Jinxiao Zhang; Antoni B Chan; Esther Yuet Ying Lau; Janet H Hsiao Individuals with insomnia misrecognize angry faces as fearful faces while missing the eyes: An eye-tracking study Journal Article SLEEPJ, 42 (2), pp. 1–11, 2019. Abstract | Links | BibTeX @article{Zhang2019,
title = {Individuals with insomnia misrecognize angry faces as fearful faces while missing the eyes: An eye-tracking study},
author = {Jinxiao Zhang and Antoni B Chan and Esther Yuet Ying Lau and Janet H Hsiao},
doi = {10.1093/sleep/zsy220},
year = {2019},
date = {2019-01-01},
journal = {SLEEPJ},
volume = {42},
number = {2},
pages = {1--11},
abstract = {Individuals with insomnia have been found to have disturbed perception of facial expressions. Through eye movement examinations, here we test the hypothesis that this effect is due to impaired visual attention functions for retrieving diagnostic features in facial expression judgments. Twenty-three individuals with insomnia symptoms and 23 controls without insomnia completed a task to categorize happy, sad, fearful, and angry facial expressions. The participants with insomnia were less accurate in recognizing angry faces and misidentified them as fearful faces more often than the controls. A hidden Markov modeling approach for eye movement data analysis revealed that when viewing facial expressions, more individuals with insomnia adopted a nose–mouth eye movement pattern focusing on the vertical face midline while more controls adopted an eyes–mouth pattern preferentially attending to lateral features, particularly the two eyes. As previous studies found that the primary diagnostic feature for recognizing angry faces is the eyes while the diagnostic features for other facial expressions involve the mouth region, missing the eye region may contribute to specific difficulties in recognizing angry facial expressions, consistent with our behavioral finding in participants with insomnia symptoms. Taken together, the findings suggest that impaired information selection through visual attention control may be related to the compromised emotion perception in individuals with insomnia.},
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Individuals with insomnia have been found to have disturbed perception of facial expressions. Through eye movement examinations, here we test the hypothesis that this effect is due to impaired visual attention functions for retrieving diagnostic features in facial expression judgments. Twenty-three individuals with insomnia symptoms and 23 controls without insomnia completed a task to categorize happy, sad, fearful, and angry facial expressions. The participants with insomnia were less accurate in recognizing angry faces and misidentified them as fearful faces more often than the controls. A hidden Markov modeling approach for eye movement data analysis revealed that when viewing facial expressions, more individuals with insomnia adopted a nose–mouth eye movement pattern focusing on the vertical face midline while more controls adopted an eyes–mouth pattern preferentially attending to lateral features, particularly the two eyes. As previous studies found that the primary diagnostic feature for recognizing angry faces is the eyes while the diagnostic features for other facial expressions involve the mouth region, missing the eye region may contribute to specific difficulties in recognizing angry facial expressions, consistent with our behavioral finding in participants with insomnia symptoms. Taken together, the findings suggest that impaired information selection through visual attention control may be related to the compromised emotion perception in individuals with insomnia. |
Gu Zhao; Qiang Liu; Jun Jiao; Peiling Zhou; Hong Li; Hong-jin Sun Dual-state modulation of the contextual cueing effect: Evidence from eye movement recordings Journal Article Journal of Vision, 12 (6), pp. 11–11, 2012. Abstract | Links | BibTeX @article{Zhao2012,
title = {Dual-state modulation of the contextual cueing effect: Evidence from eye movement recordings},
author = {Gu Zhao and Qiang Liu and Jun Jiao and Peiling Zhou and Hong Li and Hong-jin Sun},
doi = {10.1159/000171501},
year = {2012},
date = {2012-01-01},
journal = {Journal of Vision},
volume = {12},
number = {6},
pages = {11--11},
abstract = {The repeated configurations of random elements induce a better search performance than that of the displays of novel random configurations. The mechanism of such contextual cueing effect has been investigated through the use of the RT $backslash$texttimes Set Size function. There are divergent views on whether the contextual cueing effect is driven by attentional guidance or facilitation of initial perceptual processing or response selection. To explore this question, we used eye movement recording in this study, which offers information about the substages of the search task. The results suggest that the contextual cueing effect is contributed mainly by attentional guidance, and facilitation of response selection also plays a role.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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The repeated configurations of random elements induce a better search performance than that of the displays of novel random configurations. The mechanism of such contextual cueing effect has been investigated through the use of the RT $backslash$texttimes Set Size function. There are divergent views on whether the contextual cueing effect is driven by attentional guidance or facilitation of initial perceptual processing or response selection. To explore this question, we used eye movement recording in this study, which offers information about the substages of the search task. The results suggest that the contextual cueing effect is contributed mainly by attentional guidance, and facilitation of response selection also plays a role. |
Jingjing Zhao; Yonghui Wang; Donglai Liu; Liang Zhao; Peng Liu Strength of object representation: its key role in object-based attention for determining the competition result between Gestalt and top-down objects Journal Article Attention, Perception, & Psychophysics, 77 (7), pp. 2284–2292, 2015. Abstract | Links | BibTeX @article{Zhao2015,
title = {Strength of object representation: its key role in object-based attention for determining the competition result between Gestalt and top-down objects},
author = {Jingjing Zhao and Yonghui Wang and Donglai Liu and Liang Zhao and Peng Liu},
doi = {10.3758/s13414-015-0922-5},
year = {2015},
date = {2015-01-01},
journal = {Attention, Perception, & Psychophysics},
volume = {77},
number = {7},
pages = {2284--2292},
abstract = {It was found in previous studies that two types of objects (rectangles formed according to the Gestalt principle and Chinese words formed in a top-down fashion) can both induce an object-based effect. The aim of the present study was to investigate how the strength of an object representation affects the result of the competition between these two types of objects based on research carried out by Liu, Wang and Zhou [(2011) Acta Psychologica, 138(3), 397-404]. In Experiment 1, the rectangles were filled with two different colors to increase the strength of Gestalt object representation, and we found that the object effect changed significantly for the different stimulus types. Experiment 2 used Chinese words with various familiarities to manipulate the strength of the top-down object representation. As a result, the object-based effect induced by rectangles was observed only when the Chinese word familiarity was low. These results suggest that the strength of object representation determines the result of competition between different types of objects.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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It was found in previous studies that two types of objects (rectangles formed according to the Gestalt principle and Chinese words formed in a top-down fashion) can both induce an object-based effect. The aim of the present study was to investigate how the strength of an object representation affects the result of the competition between these two types of objects based on research carried out by Liu, Wang and Zhou [(2011) Acta Psychologica, 138(3), 397-404]. In Experiment 1, the rectangles were filled with two different colors to increase the strength of Gestalt object representation, and we found that the object effect changed significantly for the different stimulus types. Experiment 2 used Chinese words with various familiarities to manipulate the strength of the top-down object representation. As a result, the object-based effect induced by rectangles was observed only when the Chinese word familiarity was low. These results suggest that the strength of object representation determines the result of competition between different types of objects. |
Jing Zhao; Hang Yang; Xuchu Weng; Zhiguo Wang Emergent attentional bias toward visual word forms in the environment: Evidence from eye movements Journal Article Frontiers in Psychology, 9 , pp. 1–7, 2018. Abstract | Links | BibTeX @article{Zhao2018,
title = {Emergent attentional bias toward visual word forms in the environment: Evidence from eye movements},
author = {Jing Zhao and Hang Yang and Xuchu Weng and Zhiguo Wang},
doi = {10.3389/fpsyg.2018.01378},
year = {2018},
date = {2018-01-01},
journal = {Frontiers in Psychology},
volume = {9},
pages = {1--7},
abstract = {Young children are frequently exposed to environmental prints (e.g., billboards and product labels) that contain visual word forms on a daily basis. As the visual word forms in environmental prints are frequently used to convey information critical to an individual's survival and wellbeing (e.g., "STOP" in the stop sign), it is conceivable that an attentional bias toward words in the environment may emerge as the reading ability of young children develops. Empirical findings relevant to this issue, however, are inconclusive so far. The present study examines this issue in children in the early stages of formal reading training (grades 1, 3, and 5) with the eye-tracking technique. Children viewed images with word and non-word visual information (environmental prints) and images with the same words in standard typeface on a plain background (standard prints). For children in grade 1, the latency of their first fixations on words in environmental prints was longer than those in standard prints. This latency cost, however, was markedly reduced in grades 3 and 5, suggesting that in older children an attentional bias toward words has emerged to help filter out the non-word visual information in environmental prints. Importantly, this attentional bias was found to correlate moderately with word reading ability. These findings show that an attentional bias toward visual word forms emerges shortly after the start of formal schooling and it is closely linked to the development of reading skills.},
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Young children are frequently exposed to environmental prints (e.g., billboards and product labels) that contain visual word forms on a daily basis. As the visual word forms in environmental prints are frequently used to convey information critical to an individual's survival and wellbeing (e.g., "STOP" in the stop sign), it is conceivable that an attentional bias toward words in the environment may emerge as the reading ability of young children develops. Empirical findings relevant to this issue, however, are inconclusive so far. The present study examines this issue in children in the early stages of formal reading training (grades 1, 3, and 5) with the eye-tracking technique. Children viewed images with word and non-word visual information (environmental prints) and images with the same words in standard typeface on a plain background (standard prints). For children in grade 1, the latency of their first fixations on words in environmental prints was longer than those in standard prints. This latency cost, however, was markedly reduced in grades 3 and 5, suggesting that in older children an attentional bias toward words has emerged to help filter out the non-word visual information in environmental prints. Importantly, this attentional bias was found to correlate moderately with word reading ability. These findings show that an attentional bias toward visual word forms emerges shortly after the start of formal schooling and it is closely linked to the development of reading skills. |
Peng Zhou; Liqun Gao Scope processing in Chinese Journal Article Journal of Psycholinguistic Research, 38 (1), pp. 11–24, 2009. Abstract | Links | BibTeX @article{Zhou2009,
title = {Scope processing in Chinese},
author = {Peng Zhou and Liqun Gao},
doi = {10.1007/s10936-008-9079-x},
year = {2009},
date = {2009-01-01},
journal = {Journal of Psycholinguistic Research},
volume = {38},
number = {1},
pages = {11--24},
abstract = {The standard view maintains that quantifier scope interpretation results from an interaction between different modules: the syntax, the semantics as well as the pragmatics. Thus, by examining the mechanism of quantifier scope interpretation, we will certainly gain some insight into how these different modules interact with one another. To observe it, two experiments, an offline judgment task and an eye-tracking experiment, were conducted to investigate the interpretation of doubly quantified sentences in Chinese, like Mei-ge qiangdao dou qiang-le yi-ge yinhang (Every robber robbed a bank). According to current literature, doubly quantified sentences in Chinese like the above are unambiguous, which can only be interpreted as "for every robber x, there is a bank y, such that x robbed y"(surface scope reading), contrary to their ambiguous English counterparts, which also allow the interpretation that "there is a bank y, such that for every robber x, x robbed y"(inverse scope reading). Specifically, three questions were examined, that is, (i) What is the initial reading of doubly quantified sentences in Chinese? (ii) Whether inverse scope interpretation can be available if appropriate contexts are provided? (iii) What are the processing time courses engaged in quantifier scope interpretation? The results showed that (i) Initially, the language processor computes the surface scope representation and the inverse scope representation in parallel, thus, doubly quantified sentences in Chinese are ambiguous; (ii) The discourse information is not employed in initial processing of relative scope, it serves to evaluate the two representations in reanalysis; (iii) The lexical information of verbs affects their scope-taking patterns. We suggest that these findings provide evidence for the Modular Model, one of the major contenders in the literature on sentence processing.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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The standard view maintains that quantifier scope interpretation results from an interaction between different modules: the syntax, the semantics as well as the pragmatics. Thus, by examining the mechanism of quantifier scope interpretation, we will certainly gain some insight into how these different modules interact with one another. To observe it, two experiments, an offline judgment task and an eye-tracking experiment, were conducted to investigate the interpretation of doubly quantified sentences in Chinese, like Mei-ge qiangdao dou qiang-le yi-ge yinhang (Every robber robbed a bank). According to current literature, doubly quantified sentences in Chinese like the above are unambiguous, which can only be interpreted as "for every robber x, there is a bank y, such that x robbed y"(surface scope reading), contrary to their ambiguous English counterparts, which also allow the interpretation that "there is a bank y, such that for every robber x, x robbed y"(inverse scope reading). Specifically, three questions were examined, that is, (i) What is the initial reading of doubly quantified sentences in Chinese? (ii) Whether inverse scope interpretation can be available if appropriate contexts are provided? (iii) What are the processing time courses engaged in quantifier scope interpretation? The results showed that (i) Initially, the language processor computes the surface scope representation and the inverse scope representation in parallel, thus, doubly quantified sentences in Chinese are ambiguous; (ii) The discourse information is not employed in initial processing of relative scope, it serves to evaluate the two representations in reanalysis; (iii) The lexical information of verbs affects their scope-taking patterns. We suggest that these findings provide evidence for the Modular Model, one of the major contenders in the literature on sentence processing. |
Huihui Zhou; Robert Desimone Feature-based attention in the Frontal Eye Field and area V4 during visual search Journal Article Neuron, 70 (6), pp. 1205–1217, 2011. Abstract | Links | BibTeX @article{Zhou2011,
title = {Feature-based attention in the Frontal Eye Field and area V4 during visual search},
author = {Huihui Zhou and Robert Desimone},
doi = {10.1016/j.neuron.2011.04.032},
year = {2011},
date = {2011-01-01},
journal = {Neuron},
volume = {70},
number = {6},
pages = {1205--1217},
publisher = {Elsevier Inc.},
abstract = {When we search for a target in a crowded visual scene, we often use the distinguishing features of the target, such as color or shape, to guide our attention and eye movements. To investigate the neural mechanisms of feature-based attention, we simultaneously recorded neural responses in the frontal eye field (FEF) and area V4 while monkeys performed a visual search task. The responses of cells in both areas were modulated by feature attention, independent of spatial attention, and the magnitude of response enhancement was inversely correlated with the number of saccades needed to find the target. However, an analysis of the latency of sensory and attentional influences on responses suggested that V4 provides bottom-up sensory information about stimulus features, whereas the FEF provides a top-down attentional bias toward target features that modulates sensory processing in V4 and that could be used to guide the eyes to a searched-for target.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
When we search for a target in a crowded visual scene, we often use the distinguishing features of the target, such as color or shape, to guide our attention and eye movements. To investigate the neural mechanisms of feature-based attention, we simultaneously recorded neural responses in the frontal eye field (FEF) and area V4 while monkeys performed a visual search task. The responses of cells in both areas were modulated by feature attention, independent of spatial attention, and the magnitude of response enhancement was inversely correlated with the number of saccades needed to find the target. However, an analysis of the latency of sensory and attentional influences on responses suggested that V4 provides bottom-up sensory information about stimulus features, whereas the FEF provides a top-down attentional bias toward target features that modulates sensory processing in V4 and that could be used to guide the eyes to a searched-for target. |
Peng Zhou; Stephen Crain; Likan Zhan Sometimes children are as good as adults -- The pragmatic use of prosody in children's on-line sentence processing Journal Article Journal of Memory and Language, 67 (8), pp. 149–164, 2012. Abstract | BibTeX @article{Zhou2012a,
title = {Sometimes children are as good as adults -- The pragmatic use of prosody in children's on-line sentence processing},
author = {Peng Zhou and Stephen Crain and Likan Zhan},
year = {2012},
date = {2012-01-01},
journal = {Journal of Memory and Language},
volume = {67},
number = {8},
pages = {149--164},
abstract = {This study examined 4-year-old Mandarin-speaking children's sensitivity to prosodic cues in resolving speech act ambiguities, using eye-movement recordings. Most previous on- line studies have focused on children's use of prosody in resolving structural ambiguities. Although children have been found to be sensitive to prosodic information, they use such information less effectively than adults in on-line sentence processing. The present study takes advantage of special properties of Mandarin Chinese to investigate the role of pros- ody in children's on-line processing of ambiguities in which prosody serves to signal the illocutionary meaning of an utterance (i.e., whether the speaker is asking a question or making a statement). We found that the effect of prosody in this case was as robust in chil- dren as it was in adults. This suggests that children are as sensitive as adults in using pros- ody in on-line sentence processing, when prosody is used to resolve a pragmatic ambiguity.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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This study examined 4-year-old Mandarin-speaking children's sensitivity to prosodic cues in resolving speech act ambiguities, using eye-movement recordings. Most previous on- line studies have focused on children's use of prosody in resolving structural ambiguities. Although children have been found to be sensitive to prosodic information, they use such information less effectively than adults in on-line sentence processing. The present study takes advantage of special properties of Mandarin Chinese to investigate the role of pros- ody in children's on-line processing of ambiguities in which prosody serves to signal the illocutionary meaning of an utterance (i.e., whether the speaker is asking a question or making a statement). We found that the effect of prosody in this case was as robust in chil- dren as it was in adults. This suggests that children are as sensitive as adults in using pros- ody in on-line sentence processing, when prosody is used to resolve a pragmatic ambiguity. |
Peng Zhou; Yi Su; Stephen Crain; Liqun Gao; Likan Zhan Children's use of phonological information in ambiguity resolution: A view from Mandarin Chinese Journal Article Journal of Child Language, 39 (4), pp. 687–730, 2012. Abstract | Links | BibTeX @article{Zhou2012b,
title = {Children's use of phonological information in ambiguity resolution: A view from Mandarin Chinese},
author = {Peng Zhou and Yi Su and Stephen Crain and Liqun Gao and Likan Zhan},
doi = {10.1017/S0305000911000249},
year = {2012},
date = {2012-01-01},
journal = {Journal of Child Language},
volume = {39},
number = {4},
pages = {687--730},
abstract = {How do children develop the mapping between prosody and other levels of linguistic knowledge? This question has received considerable attention in child language research. In the present study two experiments were conducted to investigate four- to five-year-old Mandarin-speaking children's sensitivity to prosody in ambiguity resolution. Experiment 1 used eye-tracking to assess children's use of stress in resolving structural ambiguities. Experiment 2 took advantage of special properties of Mandarin to investigate whether children can use intonational cues to resolve ambiguities involving speech acts. The results of our experiments show that children's use of prosodic information in ambiguity resolution varies depending on the type of ambiguity involved. Children can use prosodic information more effectively to resolve speech act ambiguities than to resolve structural ambiguities. This finding suggests that the mapping between prosody and semantics/pragmatics in young children is better established than the mapping between prosody and syntax.},
keywords = {},
pubstate = {published},
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How do children develop the mapping between prosody and other levels of linguistic knowledge? This question has received considerable attention in child language research. In the present study two experiments were conducted to investigate four- to five-year-old Mandarin-speaking children's sensitivity to prosody in ambiguity resolution. Experiment 1 used eye-tracking to assess children's use of stress in resolving structural ambiguities. Experiment 2 took advantage of special properties of Mandarin to investigate whether children can use intonational cues to resolve ambiguities involving speech acts. The results of our experiments show that children's use of prosodic information in ambiguity resolution varies depending on the type of ambiguity involved. Children can use prosodic information more effectively to resolve speech act ambiguities than to resolve structural ambiguities. This finding suggests that the mapping between prosody and semantics/pragmatics in young children is better established than the mapping between prosody and syntax. |
Yang Zhou; Yining Liu; Wangzikang Zhang; Mingsha Zhang Asymmetric influence of egocentric representation onto allocentric perception Journal Article Journal of Neuroscience, 32 (24), pp. 8354–8360, 2012. Abstract | Links | BibTeX @article{Zhou2012c,
title = {Asymmetric influence of egocentric representation onto allocentric perception},
author = {Yang Zhou and Yining Liu and Wangzikang Zhang and Mingsha Zhang},
doi = {10.1523/JNEUROSCI.0829-12.2012},
year = {2012},
date = {2012-01-01},
journal = {Journal of Neuroscience},
volume = {32},
number = {24},
pages = {8354--8360},
abstract = {Objects in the visual world can be represented in both egocentric and allocentric coordinates. Previous studies have found that allocentric representation can affect the accuracy of spatial judgment relative to an egocentric frame, but not vice versa. Here we asked whether egocentric representation influenced the processing speed of allocentric perception. We measured the manual reaction time of human subjects in a position discrimination task in which the behavioral response purely relied on the target's allocentric location, independent of its egocentric position. We used two conditions of stimulus location: the compatible condition-allocentric left and egocentric left or allocentric right and egocentric right; the incompatible condition-allocentric left and egocentric right or allocentric right and egocentric left. We found that egocentric representation markedly influenced allocentric perception in three ways. First, in a given egocentric location, allocentric perception was significantly faster in the compatible condition than in the incompatible condition. Second, as the target became more eccentric in the visual field, the speed of allocentric perception gradually slowed down in the incompatible condition but remained unchanged in the compatible condition. Third, egocentric-allocentric incompatibility slowed allocentric perception more in the left egocentric side than the right egocentric side. These results cannot be explained by interhemispheric visuomotor transformation and stimulus-response compatibility theory. Our findings indicate that each hemisphere preferentially processes and integrates the contralateral egocentric and allocentric spatial information, and the right hemisphere receives more ipsilateral egocentric inputs than left hemisphere does.},
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Objects in the visual world can be represented in both egocentric and allocentric coordinates. Previous studies have found that allocentric representation can affect the accuracy of spatial judgment relative to an egocentric frame, but not vice versa. Here we asked whether egocentric representation influenced the processing speed of allocentric perception. We measured the manual reaction time of human subjects in a position discrimination task in which the behavioral response purely relied on the target's allocentric location, independent of its egocentric position. We used two conditions of stimulus location: the compatible condition-allocentric left and egocentric left or allocentric right and egocentric right; the incompatible condition-allocentric left and egocentric right or allocentric right and egocentric left. We found that egocentric representation markedly influenced allocentric perception in three ways. First, in a given egocentric location, allocentric perception was significantly faster in the compatible condition than in the incompatible condition. Second, as the target became more eccentric in the visual field, the speed of allocentric perception gradually slowed down in the incompatible condition but remained unchanged in the compatible condition. Third, egocentric-allocentric incompatibility slowed allocentric perception more in the left egocentric side than the right egocentric side. These results cannot be explained by interhemispheric visuomotor transformation and stimulus-response compatibility theory. Our findings indicate that each hemisphere preferentially processes and integrates the contralateral egocentric and allocentric spatial information, and the right hemisphere receives more ipsilateral egocentric inputs than left hemisphere does. |
Jing Zhou; Adam Reeves; Scott N J Watamaniuk; Stephen J Heinen Shared attention for smooth pursuit and saccades Journal Article Journal of Vision, 13 (4), pp. 1–12, 2013. Abstract | Links | BibTeX @article{Zhou2013,
title = {Shared attention for smooth pursuit and saccades},
author = {Jing Zhou and Adam Reeves and Scott N J Watamaniuk and Stephen J Heinen},
doi = {10.1167/13.4.7},
year = {2013},
date = {2013-01-01},
journal = {Journal of Vision},
volume = {13},
number = {4},
pages = {1--12},
abstract = {Identification of brief luminance decrements on parafoveal stimuli presented during smooth pursuit improves when a spot pursuit target is surrounded by a larger random dot cinematogram (RDC) that moves with it (Heinen, Jin, & Watamaniuk, 2011). This was hypothesized to occur because the RDC provided an alternative, less attention-demanding pursuit drive, and therefore released attentional resources for visual perception tasks that are shared with those used to pursue the spot. Here, we used the RDC as a tool to probe whether spot pursuit also shares attentional resources with the saccadic system. To this end, we set out to determine if the RDC could release attention from pursuit of the spot to perform a saccade task. Observers made a saccade to one of four parafoveal targets that moved with the spot pursuit stimulus. The targets either moved alone or were surrounded by an RDC (100% coherence). Saccade latency decreased with the RDC, suggesting that the RDC released attention needed to pursue the spot, which was then used for the saccade task. Additional evidence that attention was released by the RDC was obtained in an experiment in which attention was anchored to the fovea by requiring observers to detect a brief color change applied 130 ms before the saccade target appeared. This manipulation eliminated the RDC advantage. The results imply that attentional resources used by the pursuit and saccadic eye movement control systems are shared.},
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pubstate = {published},
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Identification of brief luminance decrements on parafoveal stimuli presented during smooth pursuit improves when a spot pursuit target is surrounded by a larger random dot cinematogram (RDC) that moves with it (Heinen, Jin, & Watamaniuk, 2011). This was hypothesized to occur because the RDC provided an alternative, less attention-demanding pursuit drive, and therefore released attentional resources for visual perception tasks that are shared with those used to pursue the spot. Here, we used the RDC as a tool to probe whether spot pursuit also shares attentional resources with the saccadic system. To this end, we set out to determine if the RDC could release attention from pursuit of the spot to perform a saccade task. Observers made a saccade to one of four parafoveal targets that moved with the spot pursuit stimulus. The targets either moved alone or were surrounded by an RDC (100% coherence). Saccade latency decreased with the RDC, suggesting that the RDC released attention needed to pursue the spot, which was then used for the saccade task. Additional evidence that attention was released by the RDC was obtained in an experiment in which attention was anchored to the fovea by requiring observers to detect a brief color change applied 130 ms before the saccade target appeared. This manipulation eliminated the RDC advantage. The results imply that attentional resources used by the pursuit and saccadic eye movement control systems are shared. |
Wei Zhou; Reinhold Kliegl; Ming Yan A validation of parafoveal semantic information extraction in reading Chinese Journal Article Journal of Research in Reading, 36 (SUPPL.1), pp. S51–S63, 2013. Abstract | Links | BibTeX @article{Zhou2013a,
title = {A validation of parafoveal semantic information extraction in reading Chinese},
author = {Wei Zhou and Reinhold Kliegl and Ming Yan},
doi = {10.1111/j.1467-9817.2013.01556.x},
year = {2013},
date = {2013-01-01},
journal = {Journal of Research in Reading},
volume = {36},
number = {SUPPL.1},
pages = {S51--S63},
abstract = {Parafoveal semantic processing has recently been well documented in reading Chinese sentences, presumably because of language-specific features. However, because of a large variation of fixation landing positions on pretarget words, some preview words actually were located in foveal vision when readers' eyes landed close to the end of the pretarget words. None of the previous studies has completely ruled out a possibility that the semantic preview effects might mainly arise from these foveally processed preview words. This case, whether previously observed positive evidence for parafoveal semantic processing can still hold, has been called into question. Using linear mixed models, we demonstrate in this study that semantic preview benefit from word N+1 decreased if fixation on pretarget word N was close to the preview. We argue that parafoveal semantic processing is not a consequence of foveally processed preview words.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Parafoveal semantic processing has recently been well documented in reading Chinese sentences, presumably because of language-specific features. However, because of a large variation of fixation landing positions on pretarget words, some preview words actually were located in foveal vision when readers' eyes landed close to the end of the pretarget words. None of the previous studies has completely ruled out a possibility that the semantic preview effects might mainly arise from these foveally processed preview words. This case, whether previously observed positive evidence for parafoveal semantic processing can still hold, has been called into question. Using linear mixed models, we demonstrate in this study that semantic preview benefit from word N+1 decreased if fixation on pretarget word N was close to the preview. We argue that parafoveal semantic processing is not a consequence of foveally processed preview words. |
Peng Zhou; Stephen Crain; Likan Zhan Grammatical aspect and event recognition in children's online sentence comprehension Journal Article Cognition, 133 (1), pp. 262–276, 2014. Abstract | Links | BibTeX @article{Zhou2014,
title = {Grammatical aspect and event recognition in children's online sentence comprehension},
author = {Peng Zhou and Stephen Crain and Likan Zhan},
doi = {10.1016/j.cognition.2014.06.018},
year = {2014},
date = {2014-01-01},
journal = {Cognition},
volume = {133},
number = {1},
pages = {262--276},
publisher = {133},
abstract = {This study investigated whether or not the temporal information encoded in aspectual morphemes can be used immediately by young children to facilitate event recognition during online sentence comprehension. We focused on the contrast between two grammatical aspectual morphemes in Mandarin Chinese, the perfective morpheme -le and the (imperfective) durative morpheme -zhe. The perfective morpheme -le is often used to indicate that an event has been completed, whereas the durative morpheme -zhe indicates that an event is still in progress or continuing. We were interested to see whether young children are able to use the temporal reference encoded in the two aspectual morphemes (i.e., completed versus ongoing) as rapidly as adults to facilitate event recognition during online sentence comprehension. Using the visual world eye-tracking paradigm, we tested 34 Mandarin-speaking adults and 99 Mandarin-speaking children (35 three-year-olds, 32 four-year-olds and 32 five-year-olds). On each trial, participants were presented with spoken sentences containing either of the two aspectual morphemes while viewing a visual image containing two pictures, one representing a completed event and one representing an ongoing event. Participants' eye movements were recorded from the onset of the spoken sentences. The results show that both the adults and the three age groups of children exhibited a facilitatory effect trigged by the aspectual morpheme: hearing the perfective morpheme -le triggered more eye movements to the completed event area, whereas hearing the durative morpheme -zhe triggered more eye movements to the ongoing event area. This effect occurred immediately after the onset of the aspectual morpheme, both for the adults and the three groups of children. This is evidence that young children are able to use the temporal information encoded in aspectual morphemes as rapidly as adults to facilitate event recognition. Children's eye movement patterns reflect a rapid mapping of grammatical aspect onto the temporal structures of events depicted in the visual scene.},
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pubstate = {published},
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This study investigated whether or not the temporal information encoded in aspectual morphemes can be used immediately by young children to facilitate event recognition during online sentence comprehension. We focused on the contrast between two grammatical aspectual morphemes in Mandarin Chinese, the perfective morpheme -le and the (imperfective) durative morpheme -zhe. The perfective morpheme -le is often used to indicate that an event has been completed, whereas the durative morpheme -zhe indicates that an event is still in progress or continuing. We were interested to see whether young children are able to use the temporal reference encoded in the two aspectual morphemes (i.e., completed versus ongoing) as rapidly as adults to facilitate event recognition during online sentence comprehension. Using the visual world eye-tracking paradigm, we tested 34 Mandarin-speaking adults and 99 Mandarin-speaking children (35 three-year-olds, 32 four-year-olds and 32 five-year-olds). On each trial, participants were presented with spoken sentences containing either of the two aspectual morphemes while viewing a visual image containing two pictures, one representing a completed event and one representing an ongoing event. Participants' eye movements were recorded from the onset of the spoken sentences. The results show that both the adults and the three age groups of children exhibited a facilitatory effect trigged by the aspectual morpheme: hearing the perfective morpheme -le triggered more eye movements to the completed event area, whereas hearing the durative morpheme -zhe triggered more eye movements to the ongoing event area. This effect occurred immediately after the onset of the aspectual morpheme, both for the adults and the three groups of children. This is evidence that young children are able to use the temporal information encoded in aspectual morphemes as rapidly as adults to facilitate event recognition. Children's eye movement patterns reflect a rapid mapping of grammatical aspect onto the temporal structures of events depicted in the visual scene. |
Peiyun Zhou; Kiel Christianson I “hear” what you're “saying”: Auditory perceptual simulation, reading speed, and reading comprehension Journal Article Quarterly Journal of Experimental Psychology, 69 (5), pp. 972–995, 2016. Abstract | Links | BibTeX @article{Zhou2016a,
title = {I “hear” what you're “saying”: Auditory perceptual simulation, reading speed, and reading comprehension},
author = {Peiyun Zhou and Kiel Christianson},
doi = {10.1080/17470218.2015.1018282},
year = {2016},
date = {2016-01-01},
journal = {Quarterly Journal of Experimental Psychology},
volume = {69},
number = {5},
pages = {972--995},
publisher = {Taylor & Francis},
abstract = {Auditory perceptual simulation (APS) during silent reading refers to situations in which the reader actively simulates the voice of a character or other person depicted in a text. In three eye-tracking experiments, APS effects were investigated as people read utterances attributed to a native English speaker, a non-native English speaker, or no speaker at all. APS effects were measured via online eye movements and offline comprehension probes. Results demonstrated that inducing APS during silent reading resulted in observable differences in reading speed when readers simulated the speech of faster compared to slower speakers and compared to silent reading without APS. Social attitude survey results indicated that readers' attitudes towards the native and non-native speech did not consistently influence APS-related effects. APS of both native speech and non-native speech increased reading speed, facilitated deeper, less good-enough sentence processing, and improved comprehension compared to normal silent reading.},
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Auditory perceptual simulation (APS) during silent reading refers to situations in which the reader actively simulates the voice of a character or other person depicted in a text. In three eye-tracking experiments, APS effects were investigated as people read utterances attributed to a native English speaker, a non-native English speaker, or no speaker at all. APS effects were measured via online eye movements and offline comprehension probes. Results demonstrated that inducing APS during silent reading resulted in observable differences in reading speed when readers simulated the speech of faster compared to slower speakers and compared to silent reading without APS. Social attitude survey results indicated that readers' attitudes towards the native and non-native speech did not consistently influence APS-related effects. APS of both native speech and non-native speech increased reading speed, facilitated deeper, less good-enough sentence processing, and improved comprehension compared to normal silent reading. |
Huihui Zhou; Robert John Schafer; Robert Desimone Pulvinar-cortex interactions in vision and attention Journal Article Neuron, 89 (1), pp. 209–220, 2016. Abstract | Links | BibTeX @article{Zhou2016b,
title = {Pulvinar-cortex interactions in vision and attention},
author = {Huihui Zhou and Robert John Schafer and Robert Desimone},
doi = {10.1016/j.neuron.2015.11.034},
year = {2016},
date = {2016-01-01},
journal = {Neuron},
volume = {89},
number = {1},
pages = {209--220},
publisher = {Elsevier Inc.},
abstract = {The ventro-lateral pulvinar is reciprocally connected with the visual areas of the ventral stream that are important for object recognition. To understand the mechanisms of attentive stimulus processing in this pulvinar-cortex loop, we investigated the interactions between the pulvinar, area V4, and IT cortex in a spatial-attention task. Sensory processing and the influence of attention in the pulvinar appeared to reflect its cortical inputs. However, pulvinar deactivation led to a reduction of attentional effects on firing rates and gamma synchrony in V4, a reduction of sensory-evoked responses and overall gamma coherence within V4, and severe behavioral deficits in the affected portion of the visual field. Conversely, pulvinar deactivation caused an increase in low-frequency cortical oscillations, often associated with inattention or sleep. Thus, cortical interactions with the ventro-lateral pulvinar are necessary for normal attention and sensory processing and for maintaining the cortex in an active state. The pulvinar is often proposed to modulate cortical processing with attention. Zhou et al. find that beyond any role in attention, the pulvinar input to cortex seems necessary to maintain the cortex in an active state.},
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The ventro-lateral pulvinar is reciprocally connected with the visual areas of the ventral stream that are important for object recognition. To understand the mechanisms of attentive stimulus processing in this pulvinar-cortex loop, we investigated the interactions between the pulvinar, area V4, and IT cortex in a spatial-attention task. Sensory processing and the influence of attention in the pulvinar appeared to reflect its cortical inputs. However, pulvinar deactivation led to a reduction of attentional effects on firing rates and gamma synchrony in V4, a reduction of sensory-evoked responses and overall gamma coherence within V4, and severe behavioral deficits in the affected portion of the visual field. Conversely, pulvinar deactivation caused an increase in low-frequency cortical oscillations, often associated with inattention or sleep. Thus, cortical interactions with the ventro-lateral pulvinar are necessary for normal attention and sensory processing and for maintaining the cortex in an active state. The pulvinar is often proposed to modulate cortical processing with attention. Zhou et al. find that beyond any role in attention, the pulvinar input to cortex seems necessary to maintain the cortex in an active state. |
Jifan Zhou; Chia-Lin Lee; Kuei An Li; Yung Hsuan Tien; Su Ling Yeh Does temporal integration occur for unrecognizable words in visual crowding? Journal Article PLoS ONE, 11 (2), pp. 1–15, 2016. Abstract | Links | BibTeX @article{Zhou2016c,
title = {Does temporal integration occur for unrecognizable words in visual crowding?},
author = {Jifan Zhou and Chia-Lin Lee and Kuei An Li and Yung Hsuan Tien and Su Ling Yeh},
doi = {10.1371/journal.pone.0149355},
year = {2016},
date = {2016-01-01},
journal = {PLoS ONE},
volume = {11},
number = {2},
pages = {1--15},
abstract = {? 2016 Zhou et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Visual crowding - the inability to see an object when it is surrounded by flankers in the periphery - does not block semantic activation: unrecognizable words due to visual crowding still generated robust semantic priming in subsequent lexical decision tasks. Based on the previous finding, the current study further explored whether unrecognizable crowded words can be temporally integrated into a phrase. By showing one word at a time, we presented Chinese four-word idioms with either a congruent or incongruent ending word in order to examine whether the three preceding crowded words can be temporally integrated to form a semantic context so as to affect the processing of the ending word. Results from both behavioral (Experiment 1) and Event-Related Potential (Experiment 2 and 3) measures showed congruency effect in only the non-crowded condition, which does not support the existence of unconscious multi-word integration. Aside from four-word idioms, we also found that two-word (modifier + adjective combination) integration - the simplest kind of temporal semantic integration - did not occur in visual crowding (Experiment 4). Our findings suggest that integration of temporally separated words might require conscious awareness, at least under the timing conditions tested in the current study.},
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? 2016 Zhou et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Visual crowding - the inability to see an object when it is surrounded by flankers in the periphery - does not block semantic activation: unrecognizable words due to visual crowding still generated robust semantic priming in subsequent lexical decision tasks. Based on the previous finding, the current study further explored whether unrecognizable crowded words can be temporally integrated into a phrase. By showing one word at a time, we presented Chinese four-word idioms with either a congruent or incongruent ending word in order to examine whether the three preceding crowded words can be temporally integrated to form a semantic context so as to affect the processing of the ending word. Results from both behavioral (Experiment 1) and Event-Related Potential (Experiment 2 and 3) measures showed congruency effect in only the non-crowded condition, which does not support the existence of unconscious multi-word integration. Aside from four-word idioms, we also found that two-word (modifier + adjective combination) integration - the simplest kind of temporal semantic integration - did not occur in visual crowding (Experiment 4). Our findings suggest that integration of temporally separated words might require conscious awareness, at least under the timing conditions tested in the current study. |
Lei Zhou; Yang Yang Zhang; Zuo Jun Wang; Li Lin Rao; Wei Wang; Shu Li; Xingshan Li; Zhu Yuan Liang A scanpath analysis of the risky decision-making process Journal Article Journal of Behavioral Decision Making, 29 (2-3), pp. 169–182, 2016. Abstract | Links | BibTeX @article{Zhou2016c,
title = {A scanpath analysis of the risky decision-making process},
author = {Lei Zhou and Yang Yang Zhang and Zuo Jun Wang and Li Lin Rao and Wei Wang and Shu Li and Xingshan Li and Zhu Yuan Liang},
doi = {10.1002/bdm.1943},
year = {2016},
date = {2016-01-01},
journal = {Journal of Behavioral Decision Making},
volume = {29},
number = {2-3},
pages = {169--182},
abstract = {In the field of eye tracking, scanpath analysis can reflect the sequential and temporal properties of the cognitive process. However, the advantages of scanpath analysis have not yet been utilized in the study of risky decision making. We explored the methodological applicability of scanpath analysis to test models of risky decision making by analyzing published data from the eye-tracking studies of Su et al. (2013); Wang and Li (2012), and Sun, Rao, Zhou, and Li (2014). These studies used a proportion task, an outcome-matched presentation condition, and a multiple-play condition as the baseline for comparison with information search and processing in the risky decision-making condition. We found that (i) the similarity scores of the intra-conditions were significantly higher than those of the inter-condition; (ii) the scanpaths of the two conditions were separable; and (iii) based on an inspection of typical trials, the patterns of the scanpaths differed between the two conditions. These findings suggest that scanpath analysis is reliable and valid for examining the process of risky decision making. In line with the findings of the three original studies, our results indicate that risky decision making is unlikely to be based on a weighting and summing process, as hypothesized by the family of expectation models. The findings highlight a new methodological direction for research on decision making.},
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In the field of eye tracking, scanpath analysis can reflect the sequential and temporal properties of the cognitive process. However, the advantages of scanpath analysis have not yet been utilized in the study of risky decision making. We explored the methodological applicability of scanpath analysis to test models of risky decision making by analyzing published data from the eye-tracking studies of Su et al. (2013); Wang and Li (2012), and Sun, Rao, Zhou, and Li (2014). These studies used a proportion task, an outcome-matched presentation condition, and a multiple-play condition as the baseline for comparison with information search and processing in the risky decision-making condition. We found that (i) the similarity scores of the intra-conditions were significantly higher than those of the inter-condition; (ii) the scanpaths of the two conditions were separable; and (iii) based on an inspection of typical trials, the patterns of the scanpaths differed between the two conditions. These findings suggest that scanpath analysis is reliable and valid for examining the process of risky decision making. In line with the findings of the three original studies, our results indicate that risky decision making is unlikely to be based on a weighting and summing process, as hypothesized by the family of expectation models. The findings highlight a new methodological direction for research on decision making. |
Peiyun Zhou; Kiel Christianson Auditory perceptual simulation: Simulating speech rates or accents? Journal Article Acta Psychologica, 168 , pp. 85–90, 2016. Abstract | Links | BibTeX @article{Zhou2016d,
title = {Auditory perceptual simulation: Simulating speech rates or accents?},
author = {Peiyun Zhou and Kiel Christianson},
doi = {10.1016/j.actpsy.2016.04.005},
year = {2016},
date = {2016-01-01},
journal = {Acta Psychologica},
volume = {168},
pages = {85--90},
publisher = {Elsevier B.V.},
abstract = {When readers engage in Auditory Perceptual Simulation (APS) during silent reading, they mentally simulate characteristics of voices attributed to a particular speaker or a character depicted in the text. Previous research found that auditory perceptual simulation of a faster native English speaker during silent reading led to shorter reading times that auditory perceptual simulation of a slower non-native English speaker. Yet, it was uncertain whether this difference was triggered by the different speech rates of the speakers, or by the difficulty of simulating an unfamiliar accent. The current study investigates this question by comparing faster Indian-English speech and slower American-English speech in the auditory perceptual simulation paradigm. Analyses of reading times of individual words and the full sentence reveal that the auditory perceptual simulation effect again modulated reading rate, and auditory perceptual simulation of the faster Indian-English speech led to faster reading rates compared to auditory perceptual simulation of the slower American-English speech. The comparison between this experiment and the data from Zhou and Christianson (2016) demonstrate further that the "speakers'" speech rates, rather than the difficulty of simulating a non-native accent, is the primary mechanism underlying auditory perceptual simulation effects.},
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When readers engage in Auditory Perceptual Simulation (APS) during silent reading, they mentally simulate characteristics of voices attributed to a particular speaker or a character depicted in the text. Previous research found that auditory perceptual simulation of a faster native English speaker during silent reading led to shorter reading times that auditory perceptual simulation of a slower non-native English speaker. Yet, it was uncertain whether this difference was triggered by the different speech rates of the speakers, or by the difficulty of simulating an unfamiliar accent. The current study investigates this question by comparing faster Indian-English speech and slower American-English speech in the auditory perceptual simulation paradigm. Analyses of reading times of individual words and the full sentence reveal that the auditory perceptual simulation effect again modulated reading rate, and auditory perceptual simulation of the faster Indian-English speech led to faster reading rates compared to auditory perceptual simulation of the slower American-English speech. The comparison between this experiment and the data from Zhou and Christianson (2016) demonstrate further that the "speakers'" speech rates, rather than the difficulty of simulating a non-native accent, is the primary mechanism underlying auditory perceptual simulation effects. |
Huixia Zhou; Sonja Rossi; Juan Li; Huanhuan Liu; Ran Chen; Baoguo Chen Effects of working memory capacity in processing wh-extractions: Eye-movement evidence from Chinese–English bilinguals Journal Article Journal of Research in Reading, 40 (4), pp. 420–438, 2017. Abstract | Links | BibTeX @article{Zhou2017a,
title = {Effects of working memory capacity in processing wh-extractions: Eye-movement evidence from Chinese–English bilinguals},
author = {Huixia Zhou and Sonja Rossi and Juan Li and Huanhuan Liu and Ran Chen and Baoguo Chen},
doi = {10.1111/1467-9817.12079},
year = {2017},
date = {2017-01-01},
journal = {Journal of Research in Reading},
volume = {40},
number = {4},
pages = {420--438},
abstract = {By using the eye-tracking method, the present study explores whether working memory capacity assessed via the second language (L2) reading span (L2WMC) as well as the operational span task (OSPAN) affects the processing of subject-extraction and object-extraction in Chinese–English bilinguals. Results showed that L2WMC has no effects on the grammatical judgement accuracies, the first fixation duration, gaze duration, go-past times and total fixation duration of the critical regions in wh-extractions. In contrast, OSPAN influences the first fixation duration and go-past times of the critical regions in wh-extractions. Specifically, in region 1, (e.g., Who do you think loved the comedian [region 1] with [region 2] all his heart [subject-extraction]? versus Who do you think the comedian loved [region 1] with [region 2] all his heart? [object-extraction] ), participants with high OSPAN were much slower than those with low OSPAN in their first fixation duration in reading subject-extractions, whereas there were no differences between participants with different OSPANs in reading object-extractions. In region 2, participants with high OSPAN were much faster than those with low OSPAN in their go-past times of object-extractions. These results indicated that individual differences in OSPAN rather than in L2WMC more strongly affect processing of wh-extractions. Thus, OSPAN results to be more suitable to explore the influences of working memory while processing L2 sentences with complex syntax, at least for intermediate proficient bilinguals. Results of the study also provide further support for the Capacity Theory of Comprehension.},
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tppubtype = {article}
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By using the eye-tracking method, the present study explores whether working memory capacity assessed via the second language (L2) reading span (L2WMC) as well as the operational span task (OSPAN) affects the processing of subject-extraction and object-extraction in Chinese–English bilinguals. Results showed that L2WMC has no effects on the grammatical judgement accuracies, the first fixation duration, gaze duration, go-past times and total fixation duration of the critical regions in wh-extractions. In contrast, OSPAN influences the first fixation duration and go-past times of the critical regions in wh-extractions. Specifically, in region 1, (e.g., Who do you think loved the comedian [region 1] with [region 2] all his heart [subject-extraction]? versus Who do you think the comedian loved [region 1] with [region 2] all his heart? [object-extraction] ), participants with high OSPAN were much slower than those with low OSPAN in their first fixation duration in reading subject-extractions, whereas there were no differences between participants with different OSPANs in reading object-extractions. In region 2, participants with high OSPAN were much faster than those with low OSPAN in their go-past times of object-extractions. These results indicated that individual differences in OSPAN rather than in L2WMC more strongly affect processing of wh-extractions. Thus, OSPAN results to be more suitable to explore the influences of working memory while processing L2 sentences with complex syntax, at least for intermediate proficient bilinguals. Results of the study also provide further support for the Capacity Theory of Comprehension. |
Yang Zhou; Gongchen Yu; Xuefei Yu; Si Wu; Mingsha Zhang Asymmetric representations of upper and lower visual fields in egocentric and allocentric references Journal Article Journal of Vision, 17 (1), pp. 1–11, 2017. Abstract | Links | BibTeX @article{Zhou2017b,
title = {Asymmetric representations of upper and lower visual fields in egocentric and allocentric references},
author = {Yang Zhou and Gongchen Yu and Xuefei Yu and Si Wu and Mingsha Zhang},
doi = {10.1167/17.1.9.doi},
year = {2017},
date = {2017-01-01},
journal = {Journal of Vision},
volume = {17},
number = {1},
pages = {1--11},
abstract = {Two spatial reference systems, i.e., the observer- centered (egocentric) and object-centered (allocentric) references, are most commonly used to locate the position of the external objects in space. Although we sense the world as a unified entity, visual processing is asymmetric between upper and lower visual fields (VFs). For example, the goal-directed reaching responses are more efficient in the lower VF. Such asymmetry suggests that the visual space might be composed of different realms regarding perception and action. Since the peripersonal realm includes the space that one can reach, mostly in the lower VF, it is highly likely that the peripersonal realm might mainly be represented in the egocentric reference for visuomotor operation. In contrast, the extrapersonal realm takes place away from the observer and is mostly observed in the upper VF, which is presumably represented in the allocentric reference for orientation in topographically defined space. This theory, however, has not been thoroughly tested experimentally. In the present study, we assessed the contributions of the egocentric and allocentric reference systems on visual discrimination in the upper and lower VFs through measuring the manual reaction times (RTs) of human subjects. We found that: (a) the influence of a target's egocentric location on visual discrimination was stronger in the lower VF; and (b) the influence of a target's allocentric location on visual discrimination was stronger in the upper VF. These results support the hypothesis that the upper and lower VFs are primarily represented in the allocentric and egocentric references, respectively.},
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Two spatial reference systems, i.e., the observer- centered (egocentric) and object-centered (allocentric) references, are most commonly used to locate the position of the external objects in space. Although we sense the world as a unified entity, visual processing is asymmetric between upper and lower visual fields (VFs). For example, the goal-directed reaching responses are more efficient in the lower VF. Such asymmetry suggests that the visual space might be composed of different realms regarding perception and action. Since the peripersonal realm includes the space that one can reach, mostly in the lower VF, it is highly likely that the peripersonal realm might mainly be represented in the egocentric reference for visuomotor operation. In contrast, the extrapersonal realm takes place away from the observer and is mostly observed in the upper VF, which is presumably represented in the allocentric reference for orientation in topographically defined space. This theory, however, has not been thoroughly tested experimentally. In the present study, we assessed the contributions of the egocentric and allocentric reference systems on visual discrimination in the upper and lower VFs through measuring the manual reaction times (RTs) of human subjects. We found that: (a) the influence of a target's egocentric location on visual discrimination was stronger in the lower VF; and (b) the influence of a target's allocentric location on visual discrimination was stronger in the upper VF. These results support the hypothesis that the upper and lower VFs are primarily represented in the allocentric and egocentric references, respectively. |
Yang Zhou; Lixin Liang; Yujun Pan; Ning Qian; Mingsha Zhang Sites of overt and covert attention define simultaneous spatial reference centers for visuomotor response Journal Article Scientific Reports, 7 , pp. 1–12, 2017. Abstract | Links | BibTeX @article{Zhou2017c,
title = {Sites of overt and covert attention define simultaneous spatial reference centers for visuomotor response},
author = {Yang Zhou and Lixin Liang and Yujun Pan and Ning Qian and Mingsha Zhang},
doi = {10.1038/srep46556},
year = {2017},
date = {2017-01-01},
journal = {Scientific Reports},
volume = {7},
pages = {1--12},
publisher = {Nature Publishing Group},
abstract = {The site of overt attention (fixation point) defines a spatial reference center that affects visuomotor response as indicated by the stimulus-response-compatibility (SRC) effect: When subjects press, e.g., a left key to report stimuli, their reaction time is shorter when stimuli appear to the left than to the right of the fixation. Covert attention to a peripheral site appears to define a similar reference center but previous studies did not control for confounding spatiotemporal factors or investigate the relationship between overt-and covert-attention-defined centers. Using an eye tracker to monitor fixation, we found an SRC effect relative to the site of covert attention induced by a flashed cue dot, and a concurrent reduction, but not elimination, of the overt-attention SRC effect. The two SRC effects jointly determined the overall motor reaction time. Since trials with different cue locations were randomlZhou, Y., Liang, L., Pan, Y., Qian, N., & Zhang, M. (2017). Sites of overt and covert attention define simultaneous spatial reference centers for visuomotor response. Scientific Reports, 7, 1–12. https://doi.org/10.1038/srep46556y interleaved, the integration of the two reference centers must be updated online. When the cue was invalid and diminished covert attention, the covert-attention SRC effect disappeared and the overt-attention SRC effect retained full strength, excluding non-attention-based interpretations. We conclude that both covert-and overt-attention sites define visual reference centers that simultaneously contribute to motor response.},
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The site of overt attention (fixation point) defines a spatial reference center that affects visuomotor response as indicated by the stimulus-response-compatibility (SRC) effect: When subjects press, e.g., a left key to report stimuli, their reaction time is shorter when stimuli appear to the left than to the right of the fixation. Covert attention to a peripheral site appears to define a similar reference center but previous studies did not control for confounding spatiotemporal factors or investigate the relationship between overt-and covert-attention-defined centers. Using an eye tracker to monitor fixation, we found an SRC effect relative to the site of covert attention induced by a flashed cue dot, and a concurrent reduction, but not elimination, of the overt-attention SRC effect. The two SRC effects jointly determined the overall motor reaction time. Since trials with different cue locations were randomlZhou, Y., Liang, L., Pan, Y., Qian, N., & Zhang, M. (2017). Sites of overt and covert attention define simultaneous spatial reference centers for visuomotor response. Scientific Reports, 7, 1–12. https://doi.org/10.1038/srep46556y interleaved, the integration of the two reference centers must be updated online. When the cue was invalid and diminished covert attention, the covert-attention SRC effect disappeared and the overt-attention SRC effect retained full strength, excluding non-attention-based interpretations. We conclude that both covert-and overt-attention sites define visual reference centers that simultaneously contribute to motor response. |
Ying Zhou; Bing Li; Gang Wang; Mingsha Zhang; Yujun Pan Leftward deviation and asymmetric speed of egocentric judgment between left and right visual fields Journal Article Frontiers in Neuroscience, 11 , pp. 1–10, 2017. Abstract | Links | BibTeX @article{Zhou2017d,
title = {Leftward deviation and asymmetric speed of egocentric judgment between left and right visual fields},
author = {Ying Zhou and Bing Li and Gang Wang and Mingsha Zhang and Yujun Pan},
doi = {10.3389/fnins.2017.00364},
year = {2017},
date = {2017-01-01},
journal = {Frontiers in Neuroscience},
volume = {11},
pages = {1--10},
abstract = {The egocentric reference frame is essential for body orientation and spatial localization of external objects. Recent neuroimaging and lesion studies have revealed that the right hemisphere of humans may play a more dominant role in processing egocentric information than the left hemisphere. However, previous studies of egocentric discrimination mainly focused on assessing the accuracy of egocentric judgment, leaving its timing unexplored. In addition, most previous studies never monitored the subjects' eye position during the experiments, so the influence of eye position on egocentric judgment could not be excluded. In the present study, we systematically assessed the processing of egocentric information in healthy human subjects by measuring the location of their visual subjective straight ahead (SSA) and their manual reaction time (RT) during fixation (monitored by eye tracker). In an egocentric discrimination task, subjects were required to judge the position of a visual cue relative to the subjective mid-sagittal plane and respond as quickly as possible. We found that the SSA of all subjects deviated to the left side of the body mid-sagittal plane. In addition, all subjects but one showed the longest RT at the location closest to the SSA; and in population, the RTs in the left visual field (VF) were longer than that in the right VF. These results might be due to the right hemisphere's dominant role in processing egocentric information, and its more prominent representation of the ipsilateral VF than that of the left hemisphere.},
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The egocentric reference frame is essential for body orientation and spatial localization of external objects. Recent neuroimaging and lesion studies have revealed that the right hemisphere of humans may play a more dominant role in processing egocentric information than the left hemisphere. However, previous studies of egocentric discrimination mainly focused on assessing the accuracy of egocentric judgment, leaving its timing unexplored. In addition, most previous studies never monitored the subjects' eye position during the experiments, so the influence of eye position on egocentric judgment could not be excluded. In the present study, we systematically assessed the processing of egocentric information in healthy human subjects by measuring the location of their visual subjective straight ahead (SSA) and their manual reaction time (RT) during fixation (monitored by eye tracker). In an egocentric discrimination task, subjects were required to judge the position of a visual cue relative to the subjective mid-sagittal plane and respond as quickly as possible. We found that the SSA of all subjects deviated to the left side of the body mid-sagittal plane. In addition, all subjects but one showed the longest RT at the location closest to the SSA; and in population, the RTs in the left visual field (VF) were longer than that in the right VF. These results might be due to the right hemisphere's dominant role in processing egocentric information, and its more prominent representation of the ipsilateral VF than that of the left hemisphere. |
Peng Zhou; Weiyi Ma Children's use of morphological cues in real-time event representation Journal Article Journal of Psycholinguistic Research, 47 (1), pp. 241–260, 2018. Abstract | Links | BibTeX @article{Zhou2018a,
title = {Children's use of morphological cues in real-time event representation},
author = {Peng Zhou and Weiyi Ma},
doi = {10.1007/s10936-017-9530-y},
year = {2018},
date = {2018-01-01},
journal = {Journal of Psycholinguistic Research},
volume = {47},
number = {1},
pages = {241--260},
publisher = {Springer US},
abstract = {The present study investigated whether and how fast young children can use information encoded in morphological markers during real-time event representation. Using the visual world paradigm, we tested 35 adults, 34 5-year-olds and 33 3-year-olds. The results showed that the adults, the 5-year-olds and the 3-year-olds all exhibited eye gaze patterns that reflected a rapid use of morphological cues during real-time event representation. There was no difference in the time course of the eye gaze patterns of the 5-year-olds and those of the adults, indicating that 5-year-old children already have adult-like processing abilities and they can use morphological cues as effectively as adults during real-time event representation. However, a 400 ms delay was observed in the eye gaze patterns by the 3-year-olds as compared to the 5-year-olds and the adults. We proposed that the observed difference might reflect a difference in the general cognitive processing abilities between the three age groups. Due to the immature cognitive processing abilities of 3-year-olds, it took longer for them to progress their eye movements to the target pictures as compared to older children and adults.},
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tppubtype = {article}
}
The present study investigated whether and how fast young children can use information encoded in morphological markers during real-time event representation. Using the visual world paradigm, we tested 35 adults, 34 5-year-olds and 33 3-year-olds. The results showed that the adults, the 5-year-olds and the 3-year-olds all exhibited eye gaze patterns that reflected a rapid use of morphological cues during real-time event representation. There was no difference in the time course of the eye gaze patterns of the 5-year-olds and those of the adults, indicating that 5-year-old children already have adult-like processing abilities and they can use morphological cues as effectively as adults during real-time event representation. However, a 400 ms delay was observed in the eye gaze patterns by the 3-year-olds as compared to the 5-year-olds and the adults. We proposed that the observed difference might reflect a difference in the general cognitive processing abilities between the three age groups. Due to the immature cognitive processing abilities of 3-year-olds, it took longer for them to progress their eye movements to the target pictures as compared to older children and adults. |
Yifeng Zhou; Xiaoxiao Wang; Qilin Lu; Lin Li; Bernhard A Sabel; Shihui Wei; Bensheng Qiu Visual rehabilitation training alters attentional networks in hemianopia: An fMRI study Journal Article Clinical Neurophysiology, 129 (9), pp. 1832–1841, 2018. Abstract | Links | BibTeX @article{Zhou2018b,
title = {Visual rehabilitation training alters attentional networks in hemianopia: An fMRI study},
author = {Yifeng Zhou and Xiaoxiao Wang and Qilin Lu and Lin Li and Bernhard A Sabel and Shihui Wei and Bensheng Qiu},
doi = {10.1016/j.clinph.2018.05.027},
year = {2018},
date = {2018-01-01},
journal = {Clinical Neurophysiology},
volume = {129},
number = {9},
pages = {1832--1841},
abstract = {Objective: Hemianopia is a visual field defect following post-chiasmatic damage. We now applied functional magnetic resonance imaging (fMRI) in hemianopic patients before and after visual rehabilitation training (VRT) to examine the impact of VRT on attentional function networks. Methods: Seven chronic hemianopic patients with post- chiasmatic lesions carried out a VRT for five weeks under fixation control. Before vs. after intervention, we assessed the area of residual vision (ARV), contrast sensitivity function (CSF) and functional MRI data and correlated them with each other. Results: VRT significantly improved the visual function of grating detection at the training location. Using fMRI, we found that the training led to a strengthening of connectivity between the right temporoparietal junction (rTPJ) to the insula and the anterior cingulate cortex (ACC), all of which belong to the cortical attentional network. However, no significant correlation between alterations of brain activity and improvements of either CSF or ARV was found. Conclusion: Visual rehabilitation training partially restored the deficient visual field sectors and could improve attentional network function in hemianopia. Significance: Our MRI results highlight the role of attention and the rTPJ activation as one, but not the only, component of VRT in hemianopia.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Objective: Hemianopia is a visual field defect following post-chiasmatic damage. We now applied functional magnetic resonance imaging (fMRI) in hemianopic patients before and after visual rehabilitation training (VRT) to examine the impact of VRT on attentional function networks. Methods: Seven chronic hemianopic patients with post- chiasmatic lesions carried out a VRT for five weeks under fixation control. Before vs. after intervention, we assessed the area of residual vision (ARV), contrast sensitivity function (CSF) and functional MRI data and correlated them with each other. Results: VRT significantly improved the visual function of grating detection at the training location. Using fMRI, we found that the training led to a strengthening of connectivity between the right temporoparietal junction (rTPJ) to the insula and the anterior cingulate cortex (ACC), all of which belong to the cortical attentional network. However, no significant correlation between alterations of brain activity and improvements of either CSF or ARV was found. Conclusion: Visual rehabilitation training partially restored the deficient visual field sectors and could improve attentional network function in hemianopia. Significance: Our MRI results highlight the role of attention and the rTPJ activation as one, but not the only, component of VRT in hemianopia. |
Peng Zhou; Likan Zhan; Huimin Ma Predictive language processing in preschool children with autism spectrum disorder: An eye-tracking study Journal Article Journal of Psycholinguistic Research, pp. 1–23, 2018. Abstract | Links | BibTeX @article{Zhou2018c,
title = {Predictive language processing in preschool children with autism spectrum disorder: An eye-tracking study},
author = {Peng Zhou and Likan Zhan and Huimin Ma},
doi = {10.1007/s10936-018-9612-5},
year = {2018},
date = {2018-01-01},
journal = {Journal of Psycholinguistic Research},
pages = {1--23},
publisher = {Springer US},
abstract = {Sentence comprehension relies on the abilities to rapidly integrate different types of linguistic and non-linguistic information. The present study investigated whether Mandarin-speaking preschool children with autism spectrum disorder (ASD) are able to use verb information predictively to anticipate the upcoming linguistic input during real-time sentence comprehension. 26 five-year-olds with ASD, 25 typically developing (TD) five-year-olds and 24 TD four-year-olds were tested using the visual world eye-tracking paradigm. The results showed that the 5-year-olds with ASD, like their TD peers, exhibited verb-based anticipatory eye movements during real-time sentence comprehension. No difference was observed between the ASD and TD groups in the time course of their eye gaze patterns, indicating that Mandarin-speaking preschool children with ASD are able to use verb information as effectively and rapidly as TD peers to predict the upcoming linguistic input.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Sentence comprehension relies on the abilities to rapidly integrate different types of linguistic and non-linguistic information. The present study investigated whether Mandarin-speaking preschool children with autism spectrum disorder (ASD) are able to use verb information predictively to anticipate the upcoming linguistic input during real-time sentence comprehension. 26 five-year-olds with ASD, 25 typically developing (TD) five-year-olds and 24 TD four-year-olds were tested using the visual world eye-tracking paradigm. The results showed that the 5-year-olds with ASD, like their TD peers, exhibited verb-based anticipatory eye movements during real-time sentence comprehension. No difference was observed between the ASD and TD groups in the time course of their eye gaze patterns, indicating that Mandarin-speaking preschool children with ASD are able to use verb information as effectively and rapidly as TD peers to predict the upcoming linguistic input. |
Wei Zhou; Hua Shu; Kevin Miller; Ming Yan Reliance on orthography and phonology in reading of Chinese: A developmental study Journal Article Journal of Research in Reading, 41 (2), pp. 370–391, 2018. Abstract | Links | BibTeX @article{Zhou2018d,
title = {Reliance on orthography and phonology in reading of Chinese: A developmental study},
author = {Wei Zhou and Hua Shu and Kevin Miller and Ming Yan},
doi = {10.1111/1467-9817.12111},
year = {2018},
date = {2018-01-01},
journal = {Journal of Research in Reading},
volume = {41},
number = {2},
pages = {370--391},
abstract = {Background: Disruptions of reading processes due to text substitutions can measure how readers use lexical information. Methods: With eye-movement recording, children and adults viewed sentences with either identical, orthographically similar, homophonic or unrelated substitutions of the first characters in target words. To the extent that readers rely on orthographic or phonological cues, substitutions that contain such cues should cause less disruption reading than do unrelated substitutions. Results: On pretarget words, there was a reliable reduction in gaze duration due to homophonic substitution only for children. On target words, we observed reliable recovery effects due to orthographic similarity for adults. On post-target words, adults had better orthographic-based and phonological-based recovery abilities than children. Conclusions: The combination of eye movement recording and the error detection paradigm offers a novel implicit paradigm for studying reading development: during sentence reading, beginning readers of Chinese may rely on phonological mediation, while skilled readers have more direct access to semantics from orthography.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: Disruptions of reading processes due to text substitutions can measure how readers use lexical information. Methods: With eye-movement recording, children and adults viewed sentences with either identical, orthographically similar, homophonic or unrelated substitutions of the first characters in target words. To the extent that readers rely on orthographic or phonological cues, substitutions that contain such cues should cause less disruption reading than do unrelated substitutions. Results: On pretarget words, there was a reliable reduction in gaze duration due to homophonic substitution only for children. On target words, we observed reliable recovery effects due to orthographic similarity for adults. On post-target words, adults had better orthographic-based and phonological-based recovery abilities than children. Conclusions: The combination of eye movement recording and the error detection paradigm offers a novel implicit paradigm for studying reading development: during sentence reading, beginning readers of Chinese may rely on phonological mediation, while skilled readers have more direct access to semantics from orthography. |
Wei Zhou; Aiping Wang; Hua Shu; Reinhold Kliegl; Ming Yan Word segmentation by alternating colors facilitates eye guidance in Chinese reading Journal Article Memory and Cognition, 46 (5), pp. 729–740, 2018. Abstract | Links | BibTeX @article{Zhou2018db,
title = {Word segmentation by alternating colors facilitates eye guidance in Chinese reading},
author = {Wei Zhou and Aiping Wang and Hua Shu and Reinhold Kliegl and Ming Yan},
doi = {10.3758/s13421-018-0797-5},
year = {2018},
date = {2018-01-01},
journal = {Memory and Cognition},
volume = {46},
number = {5},
pages = {729--740},
publisher = {Memory & Cognition},
abstract = {During sentence reading, low spatial frequency information afforded by spaces between words is the primary factor for eye guidance in spaced writing systems, whereas saccade generation for unspaced writing systems is less clear and under debate. In the present study, we investigated whether word-boundary information, provided by alternating colors (consistent or inconsistent with word-boundary information) influences saccade-target selection in Chinese. In Experiment 1, as compared to a baseline (i.e., uniform color) condition, word segmentation with alternating color shifted fixation location towards the center of words. In contrast, incorrect word segmentation shifted fixation location towards the beginning of words. In Experiment 2, we used a gaze-contingent paradigm to restrict the color manipulation only to the upcoming parafoveal words and replicated the results, including fixation location effects, as observed in Experiment 1. These results indicate that Chinese readers are capable of making use of parafoveal word-boundary knowledge for saccade generation, even if such information is unfamiliar to them. The present study provides novel support for the hypothesis that word segmentation is involved in the decision about where to fixate next during Chinese reading.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
During sentence reading, low spatial frequency information afforded by spaces between words is the primary factor for eye guidance in spaced writing systems, whereas saccade generation for unspaced writing systems is less clear and under debate. In the present study, we investigated whether word-boundary information, provided by alternating colors (consistent or inconsistent with word-boundary information) influences saccade-target selection in Chinese. In Experiment 1, as compared to a baseline (i.e., uniform color) condition, word segmentation with alternating color shifted fixation location towards the center of words. In contrast, incorrect word segmentation shifted fixation location towards the beginning of words. In Experiment 2, we used a gaze-contingent paradigm to restrict the color manipulation only to the upcoming parafoveal words and replicated the results, including fixation location effects, as observed in Experiment 1. These results indicate that Chinese readers are capable of making use of parafoveal word-boundary knowledge for saccade generation, even if such information is unfamiliar to them. The present study provides novel support for the hypothesis that word segmentation is involved in the decision about where to fixate next during Chinese reading. |
Wenxi Zhou; Haoyu Chen; Jiongjiong Yang Discriminative learning of similar objects enhances memory for the objects and contexts Journal Article Learning and Memory, 25 (12), pp. 601–610, 2018. Abstract | Links | BibTeX @article{Zhou2018e,
title = {Discriminative learning of similar objects enhances memory for the objects and contexts},
author = {Wenxi Zhou and Haoyu Chen and Jiongjiong Yang},
doi = {10.1101/lm.047514.118},
year = {2018},
date = {2018-01-01},
journal = {Learning and Memory},
volume = {25},
number = {12},
pages = {601--610},
abstract = {How to improve our episodic memory is an important issue in the field of memory. In the present study, we used a discriminative learning paradigm that was similar to a paradigm used in animal studies. In Experiment 1, a picture (e.g., a dog) was either paired with an identical picture, with a similar picture of the same concept (e.g., another dog), or with a picture of a different concept (e.g., a cat). Then, after intervals of 10 min, 1 d, and 1 wk, participants were asked to perform a 2-alternative forced-choice (2AFC) task to discriminate between a repeated and a similar picture, followed by the contextual judgment. In Experiment 2, eye movements were measured when participants encoded the pairs of pictures. The results showed that by discriminative learning, there was better memory performance in the 2AFC task for the "same" and "similar" conditions than for the "different" condition. In addition, there was better contextual memory performance for the "similar" condition than for the other two conditions. With regard to the eye movements, the participants were more likely to fixate on the lure objects and made more saccades between the target and lure objects in the "similar" (versus "different") condition. The number of saccades predicted how well the targets were remembered in both the 2AFC and contextual memory tasks. These results suggested that with discriminative learning of similar objects, detailed information could be better encoded by distinguishing the object from similar interferences, making the details and the contexts better remembered and retained over time.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
How to improve our episodic memory is an important issue in the field of memory. In the present study, we used a discriminative learning paradigm that was similar to a paradigm used in animal studies. In Experiment 1, a picture (e.g., a dog) was either paired with an identical picture, with a similar picture of the same concept (e.g., another dog), or with a picture of a different concept (e.g., a cat). Then, after intervals of 10 min, 1 d, and 1 wk, participants were asked to perform a 2-alternative forced-choice (2AFC) task to discriminate between a repeated and a similar picture, followed by the contextual judgment. In Experiment 2, eye movements were measured when participants encoded the pairs of pictures. The results showed that by discriminative learning, there was better memory performance in the 2AFC task for the "same" and "similar" conditions than for the "different" condition. In addition, there was better contextual memory performance for the "similar" condition than for the other two conditions. With regard to the eye movements, the participants were more likely to fixate on the lure objects and made more saccades between the target and lure objects in the "similar" (versus "different") condition. The number of saccades predicted how well the targets were remembered in both the 2AFC and contextual memory tasks. These results suggested that with discriminative learning of similar objects, detailed information could be better encoded by distinguishing the object from similar interferences, making the details and the contexts better remembered and retained over time. |
Junyi Zhou; Guojie Ma; Xingshan Li; Marcus Taft The time course of incremental word processing during Chinese reading Journal Article Reading and Writing, 31 (3), pp. 607–625, 2018. Abstract | Links | BibTeX @article{Zhou2018f,
title = {The time course of incremental word processing during Chinese reading},
author = {Junyi Zhou and Guojie Ma and Xingshan Li and Marcus Taft},
doi = {10.1007/s11145-017-9800-y},
year = {2018},
date = {2018-01-01},
journal = {Reading and Writing},
volume = {31},
number = {3},
pages = {607--625},
publisher = {Springer Netherlands},
abstract = {In the current study, we report two eye movement experiments investigating how Chinese readers process incremental words during reading. These are words where some of the component characters constitute another word (an embedded word). In two experiments, eye movements were monitored while the participants read sentences with incremental words whose first two characters (Experiment 1) or last two characters (Experiment 2) constituted a word (referred to respectively as “head-embedded” and “tail embedded”). Reading times on these words were longer when the frequencies of the embedded words were lower. However, this was only seen on first fixation duration for head-embedded words. These results suggest that embedded words are activated when Chinese readers process incremental words, and that this activation is earlier for a head-embedded word than for a tail-embedded word. These results support a hierarchical model which assumes that the representation for whole word is activated via the representation of its constituent morphemes.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In the current study, we report two eye movement experiments investigating how Chinese readers process incremental words during reading. These are words where some of the component characters constitute another word (an embedded word). In two experiments, eye movements were monitored while the participants read sentences with incremental words whose first two characters (Experiment 1) or last two characters (Experiment 2) constituted a word (referred to respectively as “head-embedded” and “tail embedded”). Reading times on these words were longer when the frequencies of the embedded words were lower. However, this was only seen on first fixation duration for head-embedded words. These results suggest that embedded words are activated when Chinese readers process incremental words, and that this activation is earlier for a head-embedded word than for a tail-embedded word. These results support a hierarchical model which assumes that the representation for whole word is activated via the representation of its constituent morphemes. |
Weina Zhu; Jan Drewes; Karl R Gegenfurtner Animal detection in natural images: effects of color and image database Journal Article PLoS ONE, 8 (10), 2013. Abstract | Links | BibTeX @article{Zhu2013,
title = {Animal detection in natural images: effects of color and image database},
author = {Weina Zhu and Jan Drewes and Karl R Gegenfurtner},
doi = {10.1371/journal.pone.0075816},
year = {2013},
date = {2013-01-01},
journal = {PLoS ONE},
volume = {8},
number = {10},
abstract = {The visual system has a remarkable ability to extract categorical information from complex natural scenes. In order to elucidate the role of low-level image features for the recognition of objects in natural scenes, we recorded saccadic eye movements and event-related potentials (ERPs) in two experiments, in which human subjects had to detect animals in previously unseen natural images. We used a new natural image database (ANID) that is free of some of the potential artifacts that have plagued the widely used COREL images. Color and grayscale images picked from the ANID and COREL databases were used. In all experiments, color images induced a greater N1 EEG component at earlier time points than grayscale images. We suggest that this influence of color in animal detection may be masked by later processes when measuring reation times. The ERP results of go/nogo and forced choice tasks were similar to those reported earlier. The non-animal stimuli induced bigger N1 than animal stimuli both in the COREL and ANID databases. This result indicates ultra-fast processing of animal images is possible irrespective of the particular database. With the ANID images, the difference between color and grayscale images is more pronounced than with the COREL images. The earlier use of the COREL images might have led to an underestimation of the contribution of color. Therefore, we conclude that the ANID image database is better suited for the investigation of the processing of natural scenes than other databases commonly used.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The visual system has a remarkable ability to extract categorical information from complex natural scenes. In order to elucidate the role of low-level image features for the recognition of objects in natural scenes, we recorded saccadic eye movements and event-related potentials (ERPs) in two experiments, in which human subjects had to detect animals in previously unseen natural images. We used a new natural image database (ANID) that is free of some of the potential artifacts that have plagued the widely used COREL images. Color and grayscale images picked from the ANID and COREL databases were used. In all experiments, color images induced a greater N1 EEG component at earlier time points than grayscale images. We suggest that this influence of color in animal detection may be masked by later processes when measuring reation times. The ERP results of go/nogo and forced choice tasks were similar to those reported earlier. The non-animal stimuli induced bigger N1 than animal stimuli both in the COREL and ANID databases. This result indicates ultra-fast processing of animal images is possible irrespective of the particular database. With the ANID images, the difference between color and grayscale images is more pronounced than with the COREL images. The earlier use of the COREL images might have led to an underestimation of the contribution of color. Therefore, we conclude that the ANID image database is better suited for the investigation of the processing of natural scenes than other databases commonly used. |
Xiao Lin Zhu; Shu Ping Tan; Fu De Yang; Wei Sun; Chong Sheng Song; Jie Feng Cui; Yan Li Zhao; Feng Mei Fan; Ya Jun Li; Yun Long Tan; Yi Zhuang Zou Visual scanning of emotional faces in schizophrenia Journal Article Neuroscience Letters, 552 , pp. 46–51, 2013. Abstract | Links | BibTeX @article{Zhu2013a,
title = {Visual scanning of emotional faces in schizophrenia},
author = {Xiao Lin Zhu and Shu Ping Tan and Fu {De Yang} and Wei Sun and Chong Sheng Song and Jie Feng Cui and Yan Li Zhao and Feng Mei Fan and Ya Jun Li and Yun Long Tan and Yi Zhuang Zou},
doi = {10.1016/j.neulet.2013.07.046},
year = {2013},
date = {2013-01-01},
journal = {Neuroscience Letters},
volume = {552},
pages = {46--51},
publisher = {Elsevier Ireland Ltd},
abstract = {This study investigated eye movement differences during facial emotion recognition between 101 patients with chronic schizophrenia and 101 controls. Independent of facial emotion, patients with schizophrenia processed facial information inefficiently; they showed significantly more direct fixations that lasted longer to interest areas (IAs), such as the eyes, nose, mouth, and nasion. The total fixation number, mean fixation duration, and total fixation duration were significantly increased in schizophrenia. Additionally, the number of fixations per second to IAs (IA fixation number/s) was significantly lower in schizophrenia. However, no differences were found between the two groups in the proportion of number of fixations to IAs or total fixation number (IA fixation number %). Interestingly, the negative symptoms of patients with schizophrenia negatively correlated with IA fixation number %. Both groups showed significantly greater attention to positive faces. Compared to controls, patients with schizophrenia exhibited significantly more fixations directed to IAs, a higher total fixation number, and lower IA fixation number/s for negative faces. These results indicate that facial processing efficiency is significantly decreased in schizophrenia, but no difference was observed in processing strategy. Patients with schizophrenia may have special deficits in processing negative faces, and negative symptoms may affect visual scanning parameters.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This study investigated eye movement differences during facial emotion recognition between 101 patients with chronic schizophrenia and 101 controls. Independent of facial emotion, patients with schizophrenia processed facial information inefficiently; they showed significantly more direct fixations that lasted longer to interest areas (IAs), such as the eyes, nose, mouth, and nasion. The total fixation number, mean fixation duration, and total fixation duration were significantly increased in schizophrenia. Additionally, the number of fixations per second to IAs (IA fixation number/s) was significantly lower in schizophrenia. However, no differences were found between the two groups in the proportion of number of fixations to IAs or total fixation number (IA fixation number %). Interestingly, the negative symptoms of patients with schizophrenia negatively correlated with IA fixation number %. Both groups showed significantly greater attention to positive faces. Compared to controls, patients with schizophrenia exhibited significantly more fixations directed to IAs, a higher total fixation number, and lower IA fixation number/s for negative faces. These results indicate that facial processing efficiency is significantly decreased in schizophrenia, but no difference was observed in processing strategy. Patients with schizophrenia may have special deficits in processing negative faces, and negative symptoms may affect visual scanning parameters. |
Rongjuan Zhu; Yangmei Luo; Xuqun You; Ziyu Wang Spatial bias induced by simple addition and subtraction: From eye movement evidence Journal Article Perception, 47 (2), pp. 143–157, 2018. Abstract | Links | BibTeX @article{Zhu2018,
title = {Spatial bias induced by simple addition and subtraction: From eye movement evidence},
author = {Rongjuan Zhu and Yangmei Luo and Xuqun You and Ziyu Wang},
doi = {10.1177/0301006617738718},
year = {2018},
date = {2018-01-01},
journal = {Perception},
volume = {47},
number = {2},
pages = {143--157},
abstract = {The associations between number and space have been intensively investigated. Recent studies indicated that this association could extend to more complex tasks, such as mental arithmetic. However, the mechanism of arithmetic-space associations in mental arithmetic was still a topic of debate. Thus, in the current study, we adopted an eye-tracking technology to investigate whether spatial bias induced by mental arithmetic was related with spatial attention shifts on the mental number line or with semantic link between the operator and space. In Experiment 1, participants moved their eyes to the corresponding response area according to the cues after solving addition and subtraction problems. The results showed that the participants moved their eyes faster to the leftward space after solving subtraction problems and faster to the right after solving addition problems. However, there was no spatial bias observed when the second operand was zero in the same time window, which indicated that the emergence of spatial bias may be associated with spatial attention shifts on the mental number line. In Experiment 2, participants responded to the operator (operation plus and operation minus) with their eyes. The results showed that mere presentation of operator did not cause spatial bias. Therefore, the arithmetic–space associations might be related with the movement along the mental number line.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The associations between number and space have been intensively investigated. Recent studies indicated that this association could extend to more complex tasks, such as mental arithmetic. However, the mechanism of arithmetic-space associations in mental arithmetic was still a topic of debate. Thus, in the current study, we adopted an eye-tracking technology to investigate whether spatial bias induced by mental arithmetic was related with spatial attention shifts on the mental number line or with semantic link between the operator and space. In Experiment 1, participants moved their eyes to the corresponding response area according to the cues after solving addition and subtraction problems. The results showed that the participants moved their eyes faster to the leftward space after solving subtraction problems and faster to the right after solving addition problems. However, there was no spatial bias observed when the second operand was zero in the same time window, which indicated that the emergence of spatial bias may be associated with spatial attention shifts on the mental number line. In Experiment 2, participants responded to the operator (operation plus and operation minus) with their eyes. The results showed that mere presentation of operator did not cause spatial bias. Therefore, the arithmetic–space associations might be related with the movement along the mental number line. |
Maryam Ziaei; William Von Hippel; Julie D Henry; Stefanie I Becker Are age effects in positivity influenced by the valence of distractors? Journal Article PLoS ONE, 10 (9), pp. 1–15, 2015. Abstract | Links | BibTeX @article{Ziaei2015,
title = {Are age effects in positivity influenced by the valence of distractors?},
author = {Maryam Ziaei and William {Von Hippel} and Julie D Henry and Stefanie I Becker},
doi = {10.1371/journal.pone.0137604},
year = {2015},
date = {2015-01-01},
journal = {PLoS ONE},
volume = {10},
number = {9},
pages = {1--15},
abstract = {An age-related ‘positivity' effect has been identified, in which older adults show an information- processing bias towards positive emotional items in attention and memory. In the present study, we examined this positivity bias by using a novel paradigm in which emotional and neutral distractors were presented along with emotionally valenced targets. Thirty-five older and 37 younger adults were asked during encoding to attend to emotional targets paired with distractors that were either neutral or opposite in valence to the target. Pupillary responses were recorded during initial encoding as well as a later incidental recognition task. Memory and pupillary responses for negative items were not affected by the valence of distractors, suggesting that positive distractors did not automatically attract older adults' attention while they were encoding negative targets. Additionally, the pupil dilation to negative items mediated the relation between age and positivity in memory. Overall, memory and pupillary responses provide converging support for a cognitive control account of positivity effects in late adulthood and suggest a link between attentional processes and the memory positivity effect.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An age-related ‘positivity' effect has been identified, in which older adults show an information- processing bias towards positive emotional items in attention and memory. In the present study, we examined this positivity bias by using a novel paradigm in which emotional and neutral distractors were presented along with emotionally valenced targets. Thirty-five older and 37 younger adults were asked during encoding to attend to emotional targets paired with distractors that were either neutral or opposite in valence to the target. Pupillary responses were recorded during initial encoding as well as a later incidental recognition task. Memory and pupillary responses for negative items were not affected by the valence of distractors, suggesting that positive distractors did not automatically attract older adults' attention while they were encoding negative targets. Additionally, the pupil dilation to negative items mediated the relation between age and positivity in memory. Overall, memory and pupillary responses provide converging support for a cognitive control account of positivity effects in late adulthood and suggest a link between attentional processes and the memory positivity effect. |
Imme C Zillekens; Marie-Luise Brandi; Juha M Lahnakoski; Atesh Koul; Valeria Manera; Cristina Becchio; Leonhard Schilbach Increased functional coupling of the left amygdala and medial prefrontal cortex during the perception of communicative point-light stimuli Journal Article Social Cognitive and Affective Neuroscience, 14 (1), pp. 97–107, 2019. Abstract | Links | BibTeX @article{Zillekens2019,
title = {Increased functional coupling of the left amygdala and medial prefrontal cortex during the perception of communicative point-light stimuli},
author = {Imme C Zillekens and Marie-Luise Brandi and Juha M Lahnakoski and Atesh Koul and Valeria Manera and Cristina Becchio and Leonhard Schilbach},
doi = {10.1093/scan/nsy105},
year = {2019},
date = {2019-01-01},
journal = {Social Cognitive and Affective Neuroscience},
volume = {14},
number = {1},
pages = {97--107},
abstract = {Interpersonal predictive coding (IPPC) describes the behavioral phenomenon whereby seeing a communicative rather than an individual action helps to discern a masked second agent. As little is known, yet, about the neural correlates of IPPC, we conducted a functional magnetic resonance imaging study in a group of 27 healthy participants using point-light displays of moving agents embedded in distractors. We discovered that seeing communicative compared to individual actions was associated with higher activation of right superior frontal gyrus, whereas the reversed contrast elicited increased neural activation in an action observation network that was activated during all trials. Our findings, therefore, potentially indicate the formation of action predictions and a reduced demand for executive control in response to communicative actions. Further, in a regression analysis, we revealed that increased perceptual sensitivity was associated with a deactivation of the left amygdala during the perceptual task. A consecutive psychophysiological interaction analysis showed increased connectivity of the amygdala with medial prefrontal cortex in the context of communicative compared to individual actions. Thus, whereas increased amygdala signaling might interfere with task-relevant processes, increased co-activation of the amygdala and the medial prefrontal cortex in a communicative context might represent the integration of mentalizing computations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Interpersonal predictive coding (IPPC) describes the behavioral phenomenon whereby seeing a communicative rather than an individual action helps to discern a masked second agent. As little is known, yet, about the neural correlates of IPPC, we conducted a functional magnetic resonance imaging study in a group of 27 healthy participants using point-light displays of moving agents embedded in distractors. We discovered that seeing communicative compared to individual actions was associated with higher activation of right superior frontal gyrus, whereas the reversed contrast elicited increased neural activation in an action observation network that was activated during all trials. Our findings, therefore, potentially indicate the formation of action predictions and a reduced demand for executive control in response to communicative actions. Further, in a regression analysis, we revealed that increased perceptual sensitivity was associated with a deactivation of the left amygdala during the perceptual task. A consecutive psychophysiological interaction analysis showed increased connectivity of the amygdala with medial prefrontal cortex in the context of communicative compared to individual actions. Thus, whereas increased amygdala signaling might interfere with task-relevant processes, increased co-activation of the amygdala and the medial prefrontal cortex in a communicative context might represent the integration of mentalizing computations. |
Ulrike Zimmer; M H"ofler; Karl Koschutnig; Anja Ischebeck; Margit Höfler; Karl Koschutnig; Anja Ischebeck Neuronal interactions in areas of spatial attention reflect avoidance of disgust, but orienting to danger Journal Article NeuroImage, 134 , pp. 94–104, 2016. Abstract | Links | BibTeX @article{Zimmer2016,
title = {Neuronal interactions in areas of spatial attention reflect avoidance of disgust, but orienting to danger},
author = {Ulrike Zimmer and M H"ofler and Karl Koschutnig and Anja Ischebeck and Margit Höfler and Karl Koschutnig and Anja Ischebeck},
doi = {10.1016/j.neuroimage.2016.03.050},
year = {2016},
date = {2016-01-01},
journal = {NeuroImage},
volume = {134},
pages = {94--104},
abstract = {For survival, it is necessary to attend quickly towards dangerous objects, but to turn away from something that is disgusting. We tested whether fear and disgust sounds direct spatial attention differently. Using fMRI, a sound cue (disgust, fear or neutral) was presented to the left or right ear. The cue was followed by a visual target (a small arrow) which was located on the same (valid) or opposite (invalid) side as the cue. Participants were required to decide whether the arrow pointed up- or downwards while ignoring the sound cue. Behaviorally, responses were faster for invalid compared to valid targets when cued by disgust, whereas the opposite pattern was observed for targets after fearful and neutral sound cues. During target presentation, activity in the visual cortex and IPL increased for targets invalidly cued with disgust, but for targets validly cued with fear which indicated a general modulation of activation due to attention. For the TPJ, an interaction in the opposite direction was observed, consistent with its role in detecting targets at unattended positions and in relocating attention. As a whole our results indicate that a disgusting sound directs spatial attention away from its location, in contrast to fearful and neutral sounds.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
For survival, it is necessary to attend quickly towards dangerous objects, but to turn away from something that is disgusting. We tested whether fear and disgust sounds direct spatial attention differently. Using fMRI, a sound cue (disgust, fear or neutral) was presented to the left or right ear. The cue was followed by a visual target (a small arrow) which was located on the same (valid) or opposite (invalid) side as the cue. Participants were required to decide whether the arrow pointed up- or downwards while ignoring the sound cue. Behaviorally, responses were faster for invalid compared to valid targets when cued by disgust, whereas the opposite pattern was observed for targets after fearful and neutral sound cues. During target presentation, activity in the visual cortex and IPL increased for targets invalidly cued with disgust, but for targets validly cued with fear which indicated a general modulation of activation due to attention. For the TPJ, an interaction in the opposite direction was observed, consistent with its role in detecting targets at unattended positions and in relocating attention. As a whole our results indicate that a disgusting sound directs spatial attention away from its location, in contrast to fearful and neutral sounds. |
Eckart Zimmerman; Markus Lappe Motor signals in visual localization Journal Article Journal of Vision, 10 (6), pp. 1–11, 2010. Abstract | Links | BibTeX @article{Zimmerman2010,
title = {Motor signals in visual localization},
author = {Eckart Zimmerman and Markus Lappe},
doi = {10.1167/10.6.2},
year = {2010},
date = {2010-01-01},
journal = {Journal of Vision},
volume = {10},
number = {6},
pages = {1--11},
abstract = {We demonstrate a strong sensory-motor coupling in visual localization in which experimental modification of the control of saccadic eye movements leads to an associated change in the perceived location of objects. Amplitudes of saccades to peripheral targets were altered by saccadic adaptation, induced by an artificial step of the saccade target during the eye movement, which leads the oculomotor system to recalibrate saccade parameters. Increasing saccade amplitudes induced concurrent shifts in perceived location of visual objects. The magnitude of perceptual shift depended on the size and persistence of errors between intended and actual saccade amplitudes. This tight agreement between the change of eye movement control and the change of localization shows that perceptual space is shaped by motor knowledge rather than simply constructed from visual input.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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We demonstrate a strong sensory-motor coupling in visual localization in which experimental modification of the control of saccadic eye movements leads to an associated change in the perceived location of objects. Amplitudes of saccades to peripheral targets were altered by saccadic adaptation, induced by an artificial step of the saccade target during the eye movement, which leads the oculomotor system to recalibrate saccade parameters. Increasing saccade amplitudes induced concurrent shifts in perceived location of visual objects. The magnitude of perceptual shift depended on the size and persistence of errors between intended and actual saccade amplitudes. This tight agreement between the change of eye movement control and the change of localization shows that perceptual space is shaped by motor knowledge rather than simply constructed from visual input. |
Eckart Zimmermann; Markus Lappe Mislocalization of flashed and stationary visual stimuli after adaptation of reactive and scanning saccades Journal Article Journal of Neuroscience, 29 (35), pp. 11055–11064, 2009. Abstract | Links | BibTeX @article{Zimmermann2009,
title = {Mislocalization of flashed and stationary visual stimuli after adaptation of reactive and scanning saccades},
author = {Eckart Zimmermann and Markus Lappe},
doi = {10.1523/JNEUROSCI.1604-09.2009},
year = {2009},
date = {2009-01-01},
journal = {Journal of Neuroscience},
volume = {29},
number = {35},
pages = {11055--11064},
abstract = {When we look around and register the location of visual objects, our oculomotor system continuously prepares targets for saccadic eye movements. The preparation of saccade targets may be directly involved in the perception of object location because modification of saccade amplitude by saccade adaptation leads to a distortion of the visual localization of briefly flashed spatial probes. Here, we investigated effects of adaptation on the localization of continuously visible objects. We compared adaptation-induced mislocalization of probes that were present for 20 ms during the saccade preparation period and of probes that were present for textgreater1 s before saccade initiation. We studied the mislocalization of these probes for two different saccade types, reactive saccades to a suddenly appearing target and scanning saccades in the self-paced viewing of a stationary scene. Adaptation of reactive saccades induced mislocalization of flashed probes. Adaptation of scanning saccades induced in addition also mislocalization of stationary objects. The mislocalization occurred in the absence of visual landmarks and must therefore originate from the change in saccade motor parameters. After adaptation of one type of saccade, the saccade amplitude change and the mislocalization transferred only weakly to the other saccade type. Mislocalization of flashed and stationary probes thus followed the selectivity of saccade adaptation. Since the generation and adaptation of reactive and scanning saccades are known to involve partially different brain mechanisms, our results suggest that visual localization of objects in space is linked to saccade targeting at multiple sites in the brain.},
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When we look around and register the location of visual objects, our oculomotor system continuously prepares targets for saccadic eye movements. The preparation of saccade targets may be directly involved in the perception of object location because modification of saccade amplitude by saccade adaptation leads to a distortion of the visual localization of briefly flashed spatial probes. Here, we investigated effects of adaptation on the localization of continuously visible objects. We compared adaptation-induced mislocalization of probes that were present for 20 ms during the saccade preparation period and of probes that were present for textgreater1 s before saccade initiation. We studied the mislocalization of these probes for two different saccade types, reactive saccades to a suddenly appearing target and scanning saccades in the self-paced viewing of a stationary scene. Adaptation of reactive saccades induced mislocalization of flashed probes. Adaptation of scanning saccades induced in addition also mislocalization of stationary objects. The mislocalization occurred in the absence of visual landmarks and must therefore originate from the change in saccade motor parameters. After adaptation of one type of saccade, the saccade amplitude change and the mislocalization transferred only weakly to the other saccade type. Mislocalization of flashed and stationary probes thus followed the selectivity of saccade adaptation. Since the generation and adaptation of reactive and scanning saccades are known to involve partially different brain mechanisms, our results suggest that visual localization of objects in space is linked to saccade targeting at multiple sites in the brain. |
Eckart Zimmermann; David Burr; Maria Concetta Morrone Spatiotopic visual maps revealed by saccadic adaptation in humans Journal Article Current Biology, 21 (16), pp. 1380–1384, 2011. Abstract | Links | BibTeX @article{Zimmermann2011,
title = {Spatiotopic visual maps revealed by saccadic adaptation in humans},
author = {Eckart Zimmermann and David Burr and Maria Concetta Morrone},
doi = {10.1016/j.cub.2011.06.014},
year = {2011},
date = {2011-01-01},
journal = {Current Biology},
volume = {21},
number = {16},
pages = {1380--1384},
publisher = {Elsevier Ltd},
abstract = {Saccadic adaptation [1] is a powerful experimental paradigm to probe the mechanisms of eye movement control and spatial vision, in which saccadic amplitudes change in response to false visual feedback. The adaptation occurs primarily in the motor system [2, 3], but there is also evidence for visual adaptation, depending on the size and the permanence of the postsaccadic error [4-7]. Here we confirm that adaptation has a strong visual component and show that the visual component of the adaptation is spatially selective in external, not retinal coordinates. Subjects performed a memory-guided, double-saccade, outward-adaptation task designed to maximize visual adaptation and to dissociate the visual and motor corrections. When the memorized saccadic target was in the same position (in external space) as that used in the adaptation training, saccade targeting was strongly influenced by adaptation (even if not matched in retinal or cranial position), but when in the same retinal or cranial but different external spatial position, targeting was unaffected by adaptation, demonstrating unequivocal spatiotopic selectivity. These results point to the existence of a spatiotopic neural representation for eye movement control that adapts in response to saccade error signals.},
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Saccadic adaptation [1] is a powerful experimental paradigm to probe the mechanisms of eye movement control and spatial vision, in which saccadic amplitudes change in response to false visual feedback. The adaptation occurs primarily in the motor system [2, 3], but there is also evidence for visual adaptation, depending on the size and the permanence of the postsaccadic error [4-7]. Here we confirm that adaptation has a strong visual component and show that the visual component of the adaptation is spatially selective in external, not retinal coordinates. Subjects performed a memory-guided, double-saccade, outward-adaptation task designed to maximize visual adaptation and to dissociate the visual and motor corrections. When the memorized saccadic target was in the same position (in external space) as that used in the adaptation training, saccade targeting was strongly influenced by adaptation (even if not matched in retinal or cranial position), but when in the same retinal or cranial but different external spatial position, targeting was unaffected by adaptation, demonstrating unequivocal spatiotopic selectivity. These results point to the existence of a spatiotopic neural representation for eye movement control that adapts in response to saccade error signals. |
Eckart Zimmermann; Maria Concetta Morrone; David Burr Visual motion distorts visual and motor space Journal Article Journal of Vision, 12 (2), pp. 10–10, 2012. Abstract | Links | BibTeX @article{Zimmermann2012,
title = {Visual motion distorts visual and motor space},
author = {Eckart Zimmermann and Maria Concetta Morrone and David Burr},
doi = {10.1167/12.2.10},
year = {2012},
date = {2012-01-01},
journal = {Journal of Vision},
volume = {12},
number = {2},
pages = {10--10},
abstract = {Much evidence suggests that visual motion can cause severe distortions in the perception of spatial position. In this study, we show that visual motion also distorts saccadic eye movements. Landing positions of saccades performed to objects presented in the vicinity of visual motion were biased in the direction of motion. The targeting errors for both saccades and perceptual reports were maximum during motion onset and were of very similar magnitude under the two conditions. These results suggest that visual motion affects a representation of spatial position, or spatial map, in a similar fashion for visuomotor action as for perception.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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Much evidence suggests that visual motion can cause severe distortions in the perception of spatial position. In this study, we show that visual motion also distorts saccadic eye movements. Landing positions of saccades performed to objects presented in the vicinity of visual motion were biased in the direction of motion. The targeting errors for both saccades and perceptual reports were maximum during motion onset and were of very similar magnitude under the two conditions. These results suggest that visual motion affects a representation of spatial position, or spatial map, in a similar fashion for visuomotor action as for perception. |
Eckart Zimmermann The reference frames in saccade adaptation Journal Article Journal of Neurophysiology, 109 , pp. 1815, 2013. Abstract | Links | BibTeX @article{Zimmermann2013a,
title = {The reference frames in saccade adaptation},
author = {Eckart Zimmermann},
doi = {10.1152/jn.00743.2012},
year = {2013},
date = {2013-01-01},
journal = {Journal of Neurophysiology},
volume = {109},
pages = {1815},
abstract = {Saccade adaptation is a mecha- nism that adjusts saccade landing positions if they systematically fail to reach their intended target. In the laboratory, saccades can be shortened or lengthened if the saccade target is displaced during execution of the saccade. In this study, saccades were performed from different positions to an adapted saccade target to dissociate adapta- tion to a spatiotopic position in external space from a combined retinotopic and spatiotopic coding. The presentation duration of the saccade target before saccade execution was systematically varied, during adaptation and during test trials, with a delayed saccade paradigm. Spatiotopic shifts in landing positions depended on a certain preview duration of the target before saccade execution. When saccades were performed immediately to a suddenly appearing target, no spatiotopic adaptation was observed. These results suggest that a spatiotopic representation of the visual target signal builds up as a function of the duration the saccade target is visible before saccade execution. Different coordinate frames might also explain the separate adaptability of reactive and voluntary saccades. Spatiotopic effects were found only in outward adaptation but not in inward adaptation, which is consistent with the idea that outward adaptation takes place at the level of the visual target representation, whereas inward adap- tation is achieved at a purely motor level.},
keywords = {},
pubstate = {published},
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Saccade adaptation is a mecha- nism that adjusts saccade landing positions if they systematically fail to reach their intended target. In the laboratory, saccades can be shortened or lengthened if the saccade target is displaced during execution of the saccade. In this study, saccades were performed from different positions to an adapted saccade target to dissociate adapta- tion to a spatiotopic position in external space from a combined retinotopic and spatiotopic coding. The presentation duration of the saccade target before saccade execution was systematically varied, during adaptation and during test trials, with a delayed saccade paradigm. Spatiotopic shifts in landing positions depended on a certain preview duration of the target before saccade execution. When saccades were performed immediately to a suddenly appearing target, no spatiotopic adaptation was observed. These results suggest that a spatiotopic representation of the visual target signal builds up as a function of the duration the saccade target is visible before saccade execution. Different coordinate frames might also explain the separate adaptability of reactive and voluntary saccades. Spatiotopic effects were found only in outward adaptation but not in inward adaptation, which is consistent with the idea that outward adaptation takes place at the level of the visual target representation, whereas inward adap- tation is achieved at a purely motor level. |
Eckart Zimmermann; Concetta M Morrone; David C Burr Spatial position information accumulates steadily over time Journal Article Journal of Neuroscience, 33 (47), pp. 18396–18401, 2013. Abstract | Links | BibTeX @article{Zimmermann2013b,
title = {Spatial position information accumulates steadily over time},
author = {Eckart Zimmermann and Concetta M Morrone and David C Burr},
doi = {10.1523/JNEUROSCI.1864-13.2013},
year = {2013},
date = {2013-01-01},
journal = {Journal of Neuroscience},
volume = {33},
number = {47},
pages = {18396--18401},
abstract = {One of the more enduring mysteries of neuroscience is how the visual system constructs robust maps of the world that remain stable in the face of frequent eye movements. Here we show that encoding the position of objects in external space is a relatively slow process, building up over hundreds of milliseconds. We display targets to which human subjects saccade after a variable preview duration. As they saccade, the target is displaced leftwards or rightwards, and subjects report the displacement direction. When subjects saccade to targets without delay, sensitivity is poor; but if the target is viewed for 300-500 ms before saccading, sensitivity is similar to that during fixation with a strong visual mask to dampen transients. These results suggest that the poor displacement thresholds usually observed in the "saccadic suppression of displacement" paradigm are a result of the fact that the target has had insufficient time to be encoded in memory, and not a result of the action of special mechanisms conferring saccadic stability. Under more natural conditions, trans-saccadic displacement detection is as good as in fixation, when the displacement transients are masked.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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One of the more enduring mysteries of neuroscience is how the visual system constructs robust maps of the world that remain stable in the face of frequent eye movements. Here we show that encoding the position of objects in external space is a relatively slow process, building up over hundreds of milliseconds. We display targets to which human subjects saccade after a variable preview duration. As they saccade, the target is displaced leftwards or rightwards, and subjects report the displacement direction. When subjects saccade to targets without delay, sensitivity is poor; but if the target is viewed for 300-500 ms before saccading, sensitivity is similar to that during fixation with a strong visual mask to dampen transients. These results suggest that the poor displacement thresholds usually observed in the "saccadic suppression of displacement" paradigm are a result of the fact that the target has had insufficient time to be encoded in memory, and not a result of the action of special mechanisms conferring saccadic stability. Under more natural conditions, trans-saccadic displacement detection is as good as in fixation, when the displacement transients are masked. |
Eckart Zimmermann; S Born; G R Fink; P Cavanagh Masking produces compression of space and time in the absence of eye movements Journal Article Journal of Neurophysiology, 112 (12), pp. 3066–3076, 2014. Abstract | Links | BibTeX @article{Zimmermann2014a,
title = {Masking produces compression of space and time in the absence of eye movements},
author = {Eckart Zimmermann and S Born and G R Fink and P Cavanagh},
doi = {10.1152/jn.00156.2014},
year = {2014},
date = {2014-01-01},
journal = {Journal of Neurophysiology},
volume = {112},
number = {12},
pages = {3066--3076},
abstract = {Whenever the visual stream is abruptly disturbed by eye movements, blinks, masks, or flashes of light, the visual system needs to retrieve the new locations of current targets and to reconstruct the timing of events to straddle the interruption. This process may introduce position and timing errors. We here report that very similar errors are seen in human subjects across three different paradigms when disturbances are caused by either eye movements, as is well known, or, as we now show, masking. We suggest that the characteristic effects of eye movements on position and time, spatial and temporal compression and saccadic suppression of displacement, are consequences of the interruption and the subsequent reconnection and are seen also when visual input is masked without any eye movements. Our data show that compression and suppression effects are not solely a product of ocular motor activity but instead can be properties of a correspondence process that links the targets of interest across interruptions in visual input, no matter what their source.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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Whenever the visual stream is abruptly disturbed by eye movements, blinks, masks, or flashes of light, the visual system needs to retrieve the new locations of current targets and to reconstruct the timing of events to straddle the interruption. This process may introduce position and timing errors. We here report that very similar errors are seen in human subjects across three different paradigms when disturbances are caused by either eye movements, as is well known, or, as we now show, masking. We suggest that the characteristic effects of eye movements on position and time, spatial and temporal compression and saccadic suppression of displacement, are consequences of the interruption and the subsequent reconnection and are seen also when visual input is masked without any eye movements. Our data show that compression and suppression effects are not solely a product of ocular motor activity but instead can be properties of a correspondence process that links the targets of interest across interruptions in visual input, no matter what their source. |
Eckart Zimmermann; Maria Concetta Morrone; David C Burr The visual component to saccadic compression. Journal Article Journal of Vision, 14 (12), pp. 13–, 2014. Abstract | Links | BibTeX @article{Zimmermann2014b,
title = {The visual component to saccadic compression.},
author = {Eckart Zimmermann and Maria Concetta Morrone and David C Burr},
doi = {10.1167/14.12.13.doi},
year = {2014},
date = {2014-01-01},
journal = {Journal of Vision},
volume = {14},
number = {12},
pages = {13--},
abstract = {Visual objects presented around the time of saccadic eye movements are strongly mislocalized towards the saccadic target, a phenomenon known as "saccadic compression." Here we show that perisaccadic compression is modulated by the presence of a visual saccadic target. When subjects saccaded to the center of the screen with no visible target, perisaccadic localization was more veridical than when tested with a target. Presenting a saccadic target sometime before saccade initiation was sufficient to induce mislocalization. When we systematically varied the onset of the saccade target, we found that it had to be presented around 100 ms before saccade execution to cause strong mislocalization: saccadic targets presented after this time caused progressively less mislocalization. When subjects made a saccade to screen center with a reference object placed at various positions, mislocalization was focused towards the position of the reference object. The results suggest that saccadic compression is a signature of a mechanism attempting to match objects seen before the saccade with those seen after.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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Visual objects presented around the time of saccadic eye movements are strongly mislocalized towards the saccadic target, a phenomenon known as "saccadic compression." Here we show that perisaccadic compression is modulated by the presence of a visual saccadic target. When subjects saccaded to the center of the screen with no visible target, perisaccadic localization was more veridical than when tested with a target. Presenting a saccadic target sometime before saccade initiation was sufficient to induce mislocalization. When we systematically varied the onset of the saccade target, we found that it had to be presented around 100 ms before saccade execution to cause strong mislocalization: saccadic targets presented after this time caused progressively less mislocalization. When subjects made a saccade to screen center with a reference object placed at various positions, mislocalization was focused towards the position of the reference object. The results suggest that saccadic compression is a signature of a mechanism attempting to match objects seen before the saccade with those seen after. |
Eckart Zimmermann Visual mislocalization during double-step saccades Journal Article Frontiers in Systems Neuroscience, 9 (132), pp. 1–9, 2015. Abstract | Links | BibTeX @article{Zimmermann2015,
title = {Visual mislocalization during double-step saccades},
author = {Eckart Zimmermann},
doi = {10.3389/fnsys.2015.00132},
year = {2015},
date = {2015-01-01},
journal = {Frontiers in Systems Neuroscience},
volume = {9},
number = {132},
pages = {1--9},
abstract = {Visual objects presented briefly at the time of saccade onset appear compressed toward the saccade target. Compression strength depends on the presentation of a visual saccade target signal and is strongly reduced during the second saccade of a double-step saccade sequence (Zimmermann et al., 2014b). Here, I tested whether perisaccadic compression is linked to saccade planning by contrasting two double-step paradigms. In the same-direction double-step paradigm, subjects were required to perform two rightward 10° saccades successively. At various times around execution of the saccade sequence a probe dot was briefly flashed. Subjects had to localize the position of the probe dot after they had completed both saccades. I found compression of visual space only at the time of the first but not at the time of the second saccade. In the reverse-direction paradigm, subjects performed first a rightward 10° saccade followed by a leftward 10° saccade back to initial fixation. In this paradigm compression was found in similar magnitude during both saccades. Analysis of the saccade parameters did not reveal indications of saccade sequence preplanning in this paradigm. I therefore conclude that saccade planning, rather than saccade execution factors, is involved in perisaccadic compression.},
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pubstate = {published},
tppubtype = {article}
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Visual objects presented briefly at the time of saccade onset appear compressed toward the saccade target. Compression strength depends on the presentation of a visual saccade target signal and is strongly reduced during the second saccade of a double-step saccade sequence (Zimmermann et al., 2014b). Here, I tested whether perisaccadic compression is linked to saccade planning by contrasting two double-step paradigms. In the same-direction double-step paradigm, subjects were required to perform two rightward 10° saccades successively. At various times around execution of the saccade sequence a probe dot was briefly flashed. Subjects had to localize the position of the probe dot after they had completed both saccades. I found compression of visual space only at the time of the first but not at the time of the second saccade. In the reverse-direction paradigm, subjects performed first a rightward 10° saccade followed by a leftward 10° saccade back to initial fixation. In this paradigm compression was found in similar magnitude during both saccades. Analysis of the saccade parameters did not reveal indications of saccade sequence preplanning in this paradigm. I therefore conclude that saccade planning, rather than saccade execution factors, is involved in perisaccadic compression. |
Eckart Zimmermann; Maria Concetta Morrone; David Burr Visual mislocalization during saccade sequences Journal Article Experimental Brain Research, 233 (2), pp. 577–585, 2015. Abstract | Links | BibTeX @article{Zimmermann2015a,
title = {Visual mislocalization during saccade sequences},
author = {Eckart Zimmermann and Maria Concetta Morrone and David Burr},
doi = {10.1007/s00221-014-4138-z},
year = {2015},
date = {2015-01-01},
journal = {Experimental Brain Research},
volume = {233},
number = {2},
pages = {577--585},
abstract = {Visual objects briefly presented around the time of saccadic eye movements are perceived compressed towards the saccade target. Here, we investigated perisaccadic mislocalization with a double-step saccade paradigm, measuring localization of small probe dots briefly flashed at various times around the sequence of the two saccades. At onset of the first saccade, probe dots were mislocalized towards the first and, to a lesser extent, also towards the second saccade target. However, there was very little mislocalization at the onset of the second saccade. When we increased the presentation duration of the saccade targets prior to onset of the saccade sequence, perisaccadic mislocalization did occur at the onset of the second saccade.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Visual objects briefly presented around the time of saccadic eye movements are perceived compressed towards the saccade target. Here, we investigated perisaccadic mislocalization with a double-step saccade paradigm, measuring localization of small probe dots briefly flashed at various times around the sequence of the two saccades. At onset of the first saccade, probe dots were mislocalized towards the first and, to a lesser extent, also towards the second saccade target. However, there was very little mislocalization at the onset of the second saccade. When we increased the presentation duration of the saccade targets prior to onset of the saccade sequence, perisaccadic mislocalization did occur at the onset of the second saccade. |
Eckart Zimmermann; F Ostendorf; C J Ploner; M Lappe Impairment of saccade adaptation in a patient with a focal thalamic lesion Journal Article Journal of Neurophysiology, 113 (7), pp. 2351–2359, 2015. Abstract | Links | BibTeX @article{Zimmermann2015b,
title = {Impairment of saccade adaptation in a patient with a focal thalamic lesion},
author = {Eckart Zimmermann and F Ostendorf and C J Ploner and M Lappe},
doi = {10.1152/jn.00744.2014},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurophysiology},
volume = {113},
number = {7},
pages = {2351--2359},
abstract = {The frequent jumps of the eyeballs-called saccades-imply the need for a constant correction of motor errors. If systematic errors are detected in saccade landing, the saccade amplitude adapts to compensate for the error. In the laboratory, saccade adaptation can be studied by displacing the saccade target. Functional selectivity of adaptation for different saccade types suggests that adaptation occurs at multiple sites in the oculomotor system. Saccade motor learning might be the result of a comparison between a prediction of the saccade landing position and its actual postsaccadic location. To investigate whether a thalamic feedback pathway might carry such a prediction signal, we studied a patient with a lesion in the posterior ventrolateral thalamic nucleus. Saccade adaptation was tested for reactive saccades, which are performed to suddenly appearing targets, and for scanning saccades, which are performed to stationary targets. For reactive saccades, we found a clear impairment in adaptation retention ipsilateral to the lesioned side and a larger-than-normal adaptation on the contralesional side. For scanning saccades, adaptation was intact on both sides and not different from the control group. Our results provide the first lesion evidence that adaptation of reactive and scanning saccades relies on distinct feedback pathways from cerebellum to cortex. They further demonstrate that saccade adaptation in humans is not restricted to the cerebellum but also involves cortical areas. The paradoxically strong adaptation for outward target steps can be explained by stronger reliance on visual targeting errors when prediction error signaling is impaired.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The frequent jumps of the eyeballs-called saccades-imply the need for a constant correction of motor errors. If systematic errors are detected in saccade landing, the saccade amplitude adapts to compensate for the error. In the laboratory, saccade adaptation can be studied by displacing the saccade target. Functional selectivity of adaptation for different saccade types suggests that adaptation occurs at multiple sites in the oculomotor system. Saccade motor learning might be the result of a comparison between a prediction of the saccade landing position and its actual postsaccadic location. To investigate whether a thalamic feedback pathway might carry such a prediction signal, we studied a patient with a lesion in the posterior ventrolateral thalamic nucleus. Saccade adaptation was tested for reactive saccades, which are performed to suddenly appearing targets, and for scanning saccades, which are performed to stationary targets. For reactive saccades, we found a clear impairment in adaptation retention ipsilateral to the lesioned side and a larger-than-normal adaptation on the contralesional side. For scanning saccades, adaptation was intact on both sides and not different from the control group. Our results provide the first lesion evidence that adaptation of reactive and scanning saccades relies on distinct feedback pathways from cerebellum to cortex. They further demonstrate that saccade adaptation in humans is not restricted to the cerebellum but also involves cortical areas. The paradoxically strong adaptation for outward target steps can be explained by stronger reliance on visual targeting errors when prediction error signaling is impaired. |
Eckart Zimmermann Spatiotopic buildup of saccade target representation depends on target size Journal Article Journal of Vision, 16 (15), pp. 11, 2016. Abstract | Links | BibTeX @article{Zimmermann2016,
title = {Spatiotopic buildup of saccade target representation depends on target size},
author = {Eckart Zimmermann},
doi = {10.1167/16.15.11},
year = {2016},
date = {2016-01-01},
journal = {Journal of Vision},
volume = {16},
number = {15},
pages = {11},
abstract = {How we maintain spatial stability across saccade eye movements is an open question in visual neuroscience. A phenomenon that has received much attention in the field is our seemingly poor ability to discriminate the direction of transsaccadic target displacements. We have recently shown that discrimination performance increases the longer the saccade target has been previewed before saccade execution (Zimmermann, Morrone, & Burr, 2013). We have argued that the spatial representation of briefly presented stimuli is weak but that a strong representation is needed for transsaccadic, i.e., spatiotopic localization. Another factor that modulates the representation of saccade targets is stimulus size. The representation of spatially extended targets is more noisy than that of point-like targets. Here, I show that theincreaseintranssaccadic displacement discrimination as a function of saccade target preview duration depends on target size. This effect was found for spatially extended targets—thus replicating the results of Zimmermann et al. (2013)— but not for point-like targets. An analysis of saccade parameters revealed that the constant error for reaching the saccade target was bigger for spatially extended than for point-like targets, consistent with weaker representation of bigger targets. These results show that transsaccadic displacement discrimination becomes accurate when saccade targets are spatially extended and presented longer, thus resembling closer stimuli in real-world environments.},
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How we maintain spatial stability across saccade eye movements is an open question in visual neuroscience. A phenomenon that has received much attention in the field is our seemingly poor ability to discriminate the direction of transsaccadic target displacements. We have recently shown that discrimination performance increases the longer the saccade target has been previewed before saccade execution (Zimmermann, Morrone, & Burr, 2013). We have argued that the spatial representation of briefly presented stimuli is weak but that a strong representation is needed for transsaccadic, i.e., spatiotopic localization. Another factor that modulates the representation of saccade targets is stimulus size. The representation of spatially extended targets is more noisy than that of point-like targets. Here, I show that theincreaseintranssaccadic displacement discrimination as a function of saccade target preview duration depends on target size. This effect was found for spatially extended targets—thus replicating the results of Zimmermann et al. (2013)— but not for point-like targets. An analysis of saccade parameters revealed that the constant error for reaching the saccade target was bigger for spatially extended than for point-like targets, consistent with weaker representation of bigger targets. These results show that transsaccadic displacement discrimination becomes accurate when saccade targets are spatially extended and presented longer, thus resembling closer stimuli in real-world environments. |
Eckart Zimmermann; Maria Concetta Morrone; David Burr Adaptation to size affects saccades with long but not short latencies Journal Article Journal of Vision, 16 (7), pp. 2, 2016. Abstract | Links | BibTeX @article{Zimmermann2016a,
title = {Adaptation to size affects saccades with long but not short latencies},
author = {Eckart Zimmermann and Maria Concetta Morrone and David Burr},
doi = {10.1167/16.7.2},
year = {2016},
date = {2016-01-01},
journal = {Journal of Vision},
volume = {16},
number = {7},
pages = {2},
abstract = {Maintained exposure to a specific stimulus property— such as size, color, or motion—induces perceptual adaptation aftereffects, usually in the opposite direction to that of the adaptor. Here we studied how adaptation to size affects perceived position and visually guided action (saccadic eye movements) to that position. Subjects saccaded to the border of a diamond-shaped object after adaptation to a smaller diamond shape. For saccades in the normal latency range, amplitudes decreased, consistent with saccading to a larger object. Short-latency saccades, however, tended to be affected less by the adaptation, suggesting that they were only partly triggered by a signal representing the illusory target position. We also tested size perception after adaptation, followed by a mask stimulus at the probe location after various delays. Similar size adaptation magnitudes were found for all probe-mask delays. In agreement with earlier studies, these results suggest that the duration of the saccade latency period determines the reference frame that codes the probe location.},
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Maintained exposure to a specific stimulus property— such as size, color, or motion—induces perceptual adaptation aftereffects, usually in the opposite direction to that of the adaptor. Here we studied how adaptation to size affects perceived position and visually guided action (saccadic eye movements) to that position. Subjects saccaded to the border of a diamond-shaped object after adaptation to a smaller diamond shape. For saccades in the normal latency range, amplitudes decreased, consistent with saccading to a larger object. Short-latency saccades, however, tended to be affected less by the adaptation, suggesting that they were only partly triggered by a signal representing the illusory target position. We also tested size perception after adaptation, followed by a mask stimulus at the probe location after various delays. Similar size adaptation magnitudes were found for all probe-mask delays. In agreement with earlier studies, these results suggest that the duration of the saccade latency period determines the reference frame that codes the probe location. |
Eckart Zimmermann; R Weidner; R O Abdollahi; G R Fink Spatiotopic adaptation in visual areas Journal Article Journal of Neuroscience, 36 (37), pp. 9526–9534, 2016. Abstract | Links | BibTeX @article{Zimmermann2016b,
title = {Spatiotopic adaptation in visual areas},
author = {Eckart Zimmermann and R Weidner and R O Abdollahi and G R Fink},
doi = {10.1523/JNEUROSCI.0052-16.2016},
year = {2016},
date = {2016-01-01},
journal = {Journal of Neuroscience},
volume = {36},
number = {37},
pages = {9526--9534},
abstract = {The ability to perceive the visual world around us as spatially stable despite frequent eye movements is one of the long-standing mysteries of neuroscience. The existence of neural mechanisms processing spatiotopic information is indispensable for a successful interaction with the external world. However, how the brain handles spatiotopic information remains a matter of debate. We here combined behavioral and fMRI adaptation to investigate the coding of spatiotopic information in the human brain. Subjects were adapted by a prolonged presentation of a tilted grating. Thereafter, they performed a saccade followed by the brief presentation of a probe. This procedure allowed dissociating adaptation aftereffects at retinal and spatiotopic positions. We found significant behavioral and functional adaptation in both retinal and spatiotopic positions, indicating information transfer into a spatiotopic coordinate system. The brain regions involved were located in ventral visual areas V3, V4, and VO. Our findings suggest that spatiotopic representations involved in maintaining visual stability are constructed by dynamically remapping visual feature information between retinotopic regions within early visual areas.},
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The ability to perceive the visual world around us as spatially stable despite frequent eye movements is one of the long-standing mysteries of neuroscience. The existence of neural mechanisms processing spatiotopic information is indispensable for a successful interaction with the external world. However, how the brain handles spatiotopic information remains a matter of debate. We here combined behavioral and fMRI adaptation to investigate the coding of spatiotopic information in the human brain. Subjects were adapted by a prolonged presentation of a tilted grating. Thereafter, they performed a saccade followed by the brief presentation of a probe. This procedure allowed dissociating adaptation aftereffects at retinal and spatiotopic positions. We found significant behavioral and functional adaptation in both retinal and spatiotopic positions, indicating information transfer into a spatiotopic coordinate system. The brain regions involved were located in ventral visual areas V3, V4, and VO. Our findings suggest that spatiotopic representations involved in maintaining visual stability are constructed by dynamically remapping visual feature information between retinotopic regions within early visual areas. |
Eckart Zimmermann; Ralph Weidner; Gereon R Fink Spatiotopic updating of visual feature information Journal Article Journal of Vision, 17 (12), pp. 6, 2017. Abstract | Links | BibTeX @article{Zimmermann2017,
title = {Spatiotopic updating of visual feature information},
author = {Eckart Zimmermann and Ralph Weidner and Gereon R Fink},
doi = {10.1167/17.12.6.doi},
year = {2017},
date = {2017-01-01},
journal = {Journal of Vision},
volume = {17},
number = {12},
pages = {6},
abstract = {Saccades shift the retina with high-speed motion. In order to compensate for the sudden displacement, the visuomotor system needs to combine saccade-related information and visual metrics. Many neurons in oculomotor but also in visual areas shift their receptive field shortly before the execution of a saccade (Duhamel, Colby, & Goldberg, 1992; Nakamura & Colby, 2002). These shifts supposedly enable the binding of information from before and after the saccade. It is a matter of current debate whether these shifts are merely location based (i.e., involve remapping of abstract spatial coordinates) or also comprise information about visual features. We have recently presented fMRI evidence for a feature-based remapping mechanism in visual areas V3, V4, and VO (Zimmermann, Weidner, Abdollahi, & Fink, 2016). In particular, we found fMRI adaptation in cortical regions representing a stimulus' retinotopic as well as its spatiotopic position. Here, we asked whether spatiotopic adaptation exists independently from retinotopic adaptation and which type of information is behaviorally more relevant after saccade execution. We first adapted at the saccade target location only and found a spatiotopic tilt aftereffect. Then, we simultaneously adapted both the fixation and the saccade target location but with opposite tilt orientations. As a result, adaptation from the fixation location was carried retinotopically to the saccade target position. The opposite tilt orientation at the retinotopic location altered the effects induced by spatiotopic adaptation. More precisely, it cancelled out spatiotopic adaptation at the saccade target location. We conclude that retinotopic and spatiotopic visual adaptation are independent effects.},
keywords = {},
pubstate = {published},
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Saccades shift the retina with high-speed motion. In order to compensate for the sudden displacement, the visuomotor system needs to combine saccade-related information and visual metrics. Many neurons in oculomotor but also in visual areas shift their receptive field shortly before the execution of a saccade (Duhamel, Colby, & Goldberg, 1992; Nakamura & Colby, 2002). These shifts supposedly enable the binding of information from before and after the saccade. It is a matter of current debate whether these shifts are merely location based (i.e., involve remapping of abstract spatial coordinates) or also comprise information about visual features. We have recently presented fMRI evidence for a feature-based remapping mechanism in visual areas V3, V4, and VO (Zimmermann, Weidner, Abdollahi, & Fink, 2016). In particular, we found fMRI adaptation in cortical regions representing a stimulus' retinotopic as well as its spatiotopic position. Here, we asked whether spatiotopic adaptation exists independently from retinotopic adaptation and which type of information is behaviorally more relevant after saccade execution. We first adapted at the saccade target location only and found a spatiotopic tilt aftereffect. Then, we simultaneously adapted both the fixation and the saccade target location but with opposite tilt orientations. As a result, adaptation from the fixation location was carried retinotopically to the saccade target position. The opposite tilt orientation at the retinotopic location altered the effects induced by spatiotopic adaptation. More precisely, it cancelled out spatiotopic adaptation at the saccade target location. We conclude that retinotopic and spatiotopic visual adaptation are independent effects. |
E Zimmermann; M C Morrone; P Binda Perception during double-step saccades Journal Article Scientific Reports, 8 (1), pp. 1–9, 2018. Abstract | Links | BibTeX @article{Zimmermann2018,
title = {Perception during double-step saccades},
author = {E Zimmermann and M C Morrone and P Binda},
doi = {10.1038/s41598-017-18554-w},
year = {2018},
date = {2018-01-01},
journal = {Scientific Reports},
volume = {8},
number = {1},
pages = {1--9},
publisher = {Springer US},
abstract = {How the visual system achieves perceptual stability across saccadic eye movements is a long-standing question in neuroscience. It has been proposed that an efference copy informs vision about upcoming saccades, and this might lead to shifting spatial coordinates and suppressing image motion. Here we ask whether these two aspects of visual stability are interdependent or may be dissociated under special conditions. We study a memory-guided double-step saccade task, where two saccades are executed in quick succession. Previous studies have led to the hypothesis that in this paradigm the two saccades are planned in parallel, with a single efference copy signal generated at the start of the double-step sequence, i.e. before the first saccade. In line with this hypothesis, we find that visual stability is impaired during the second saccade, which is consistent with (accurate) efference copy information being unavailable during the second saccade. However, we find that saccadic suppression is normal during the second saccade. Thus, the second saccade of a double-step sequence instantiates a dissociation between visual stability and saccadic suppression: stability is impaired even though suppression is strong.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
How the visual system achieves perceptual stability across saccadic eye movements is a long-standing question in neuroscience. It has been proposed that an efference copy informs vision about upcoming saccades, and this might lead to shifting spatial coordinates and suppressing image motion. Here we ask whether these two aspects of visual stability are interdependent or may be dissociated under special conditions. We study a memory-guided double-step saccade task, where two saccades are executed in quick succession. Previous studies have led to the hypothesis that in this paradigm the two saccades are planned in parallel, with a single efference copy signal generated at the start of the double-step sequence, i.e. before the first saccade. In line with this hypothesis, we find that visual stability is impaired during the second saccade, which is consistent with (accurate) efference copy information being unavailable during the second saccade. However, we find that saccadic suppression is normal during the second saccade. Thus, the second saccade of a double-step sequence instantiates a dissociation between visual stability and saccadic suppression: stability is impaired even though suppression is strong. |
Marc Zirnsak; R G K Gerhards; R Kiani; M Lappe; F H Hamker Anticipatory saccade target processing and the presaccadic transfer of visual features Journal Article Journal of Neuroscience, 31 (49), pp. 17887–17891, 2011. Abstract | Links | BibTeX @article{Zirnsak2011,
title = {Anticipatory saccade target processing and the presaccadic transfer of visual features},
author = {Marc Zirnsak and R G K Gerhards and R Kiani and M Lappe and F H Hamker},
doi = {10.1523/JNEUROSCI.2465-11.2011},
year = {2011},
date = {2011-01-01},
journal = {Journal of Neuroscience},
volume = {31},
number = {49},
pages = {17887--17891},
abstract = {As we shift our gaze to explore the visual world, information enters cortex in a sequence of successive snapshots, interrupted by phases of blur. Our experience, in contrast, appears like a movie of a continuous stream of objects embedded in a stable world. This perception of stability across eye movements has been linked to changes in spatial sensitivity of visual neurons anticipating the upcoming saccade, often referred to as shifting receptive fields (Duhamel et al., 1992; Walker et al., 1995; Umeno and Goldberg, 1997; Nakamura and Colby, 2002). How exactly these receptive field dynamics contribute to perceptual stability is currently not clear. Anticipatory receptive field shifts toward the future, postsaccadic position may bridge the transient perisaccadic epoch (Sommer and Wurtz, 2006; Wurtz, 2008; Melcher and Colby, 2008). Alternatively, a presaccadic shift of receptive fields toward the saccade target area (Tolias et al., 2001) may serve to focus visual resources onto the most relevant objects in the postsaccadic scene (Hamker et al., 2008). In this view, shifts of feature detectors serve to facilitate the processing of the peripheral visual content before it is foveated. While this conception is consistent with previous observations on receptive field dynamics and on perisaccadic compression (Ross et al., 1997; Morrone et al., 1997; Kaiser and Lappe, 2004), it predicts that receptive fields beyond the saccade target shift toward the saccade target rather than in the direction of the saccade. We have tested this prediction in human observers via the presaccadic transfer of the tilt-aftereffect (Melcher, 2007).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
As we shift our gaze to explore the visual world, information enters cortex in a sequence of successive snapshots, interrupted by phases of blur. Our experience, in contrast, appears like a movie of a continuous stream of objects embedded in a stable world. This perception of stability across eye movements has been linked to changes in spatial sensitivity of visual neurons anticipating the upcoming saccade, often referred to as shifting receptive fields (Duhamel et al., 1992; Walker et al., 1995; Umeno and Goldberg, 1997; Nakamura and Colby, 2002). How exactly these receptive field dynamics contribute to perceptual stability is currently not clear. Anticipatory receptive field shifts toward the future, postsaccadic position may bridge the transient perisaccadic epoch (Sommer and Wurtz, 2006; Wurtz, 2008; Melcher and Colby, 2008). Alternatively, a presaccadic shift of receptive fields toward the saccade target area (Tolias et al., 2001) may serve to focus visual resources onto the most relevant objects in the postsaccadic scene (Hamker et al., 2008). In this view, shifts of feature detectors serve to facilitate the processing of the peripheral visual content before it is foveated. While this conception is consistent with previous observations on receptive field dynamics and on perisaccadic compression (Ross et al., 1997; Morrone et al., 1997; Kaiser and Lappe, 2004), it predicts that receptive fields beyond the saccade target shift toward the saccade target rather than in the direction of the saccade. We have tested this prediction in human observers via the presaccadic transfer of the tilt-aftereffect (Melcher, 2007). |
Hamed Zivari Adab; Rufin Vogels Practicing coarse orientation discrimination improves orientation signals in macaque cortical area V4 Journal Article Current Biology, 21 (19), pp. 1661–1666, 2011. Abstract | Links | BibTeX @article{ZivariAdab2011,
title = {Practicing coarse orientation discrimination improves orientation signals in macaque cortical area V4},
author = {Hamed {Zivari Adab} and Rufin Vogels},
doi = {10.1016/j.cub.2011.08.037},
year = {2011},
date = {2011-01-01},
journal = {Current Biology},
volume = {21},
number = {19},
pages = {1661--1666},
publisher = {Elsevier Ltd},
abstract = {Practice improves the performance in visual tasks, but mechanisms underlying this adult brain plasticity are unclear. Single-cell studies reported no [1], weak [2], or moderate [3, 4] perceptual learning-related changes in macaque visual areas V1 and V4, whereas none were found in middle temporal (MT) [5]. These conflicting results and modeling of human (e.g., [6, 7]) and monkey data [8] suggested that changes in the readout of visual cortical signals underlie perceptual learning, rather than changes in these signals. In the V4 learning studies, monkeys discriminated small differences in orientation, whereas in the MT study, the animals discriminated opponent motion directions. Analogous to the latter study, we trained monkeys to discriminate static orthogonal orientations masked by noise. V4 neurons showed robust increases in their capacity to discriminate the trained orientations during the course of the training. This effect was observed during discrimination and passive fixation but specifically for the trained orientations. The improvement in neural discrimination was due to decreased response variability and an increase of the difference between the mean responses for the two trained orientations. These findings demonstrate that perceptual learning in a coarse discrimination task indeed can change the response properties of a cortical sensory area.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Practice improves the performance in visual tasks, but mechanisms underlying this adult brain plasticity are unclear. Single-cell studies reported no [1], weak [2], or moderate [3, 4] perceptual learning-related changes in macaque visual areas V1 and V4, whereas none were found in middle temporal (MT) [5]. These conflicting results and modeling of human (e.g., [6, 7]) and monkey data [8] suggested that changes in the readout of visual cortical signals underlie perceptual learning, rather than changes in these signals. In the V4 learning studies, monkeys discriminated small differences in orientation, whereas in the MT study, the animals discriminated opponent motion directions. Analogous to the latter study, we trained monkeys to discriminate static orthogonal orientations masked by noise. V4 neurons showed robust increases in their capacity to discriminate the trained orientations during the course of the training. This effect was observed during discrimination and passive fixation but specifically for the trained orientations. The improvement in neural discrimination was due to decreased response variability and an increase of the difference between the mean responses for the two trained orientations. These findings demonstrate that perceptual learning in a coarse discrimination task indeed can change the response properties of a cortical sensory area. |
D Zoccolan Multiple object response normalization in monkey inferotemporal cortex Journal Article Journal of Neuroscience, 25 (36), pp. 8150–8164, 2005. Abstract | Links | BibTeX @article{Zoccolan2005,
title = {Multiple object response normalization in monkey inferotemporal cortex},
author = {D Zoccolan},
doi = {10.1523/JNEUROSCI.2058-05.2005},
year = {2005},
date = {2005-01-01},
journal = {Journal of Neuroscience},
volume = {25},
number = {36},
pages = {8150--8164},
abstract = {The highest stages of the visual ventral pathway are commonly assumed to provide robust representation of object identity by disregard- ingconfoundingfactorssuchas object position, size, illumination,andthe presence of other objects (clutter).However,whereasneuronal responses in monkey inferotemporal cortex (IT) can show robust tolerance to position and size changes, previous work shows that responses to preferred objects are usually reduced by the presence of nonpreferred objects. More broadly, we do not yet understand multiple object representation in IT. In this study, we systematically examined IT responses to pairs and triplets of objects in three passively viewing monkeys across a broad range of object effectiveness.Wefound that, at least under these limited clutter conditions, a large fraction of the response of each IT neuron to multiple objects is reliably predicted as the average of its responses to the constituent objects in isolation. That is, multiple object responses depend primarilyonthe relative effectiveness of the constituent objects, regardless of object identity. This average effect becomes virtually perfect when populations of IT neurons are pooled. Furthermore, the average effect cannot simply be explained by attentional shifts but behaves as a primarily feedforward response property. Together, our obser- vations are most consistent with mechanistic models in which IT neuronal outputs are normalized by summed synaptic drive into IT or spiking activity within IT and suggest that normalization mechanisms previously revealed at earlier visual areas are operating through- out the ventral visual stream.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The highest stages of the visual ventral pathway are commonly assumed to provide robust representation of object identity by disregard- ingconfoundingfactorssuchas object position, size, illumination,andthe presence of other objects (clutter).However,whereasneuronal responses in monkey inferotemporal cortex (IT) can show robust tolerance to position and size changes, previous work shows that responses to preferred objects are usually reduced by the presence of nonpreferred objects. More broadly, we do not yet understand multiple object representation in IT. In this study, we systematically examined IT responses to pairs and triplets of objects in three passively viewing monkeys across a broad range of object effectiveness.Wefound that, at least under these limited clutter conditions, a large fraction of the response of each IT neuron to multiple objects is reliably predicted as the average of its responses to the constituent objects in isolation. That is, multiple object responses depend primarilyonthe relative effectiveness of the constituent objects, regardless of object identity. This average effect becomes virtually perfect when populations of IT neurons are pooled. Furthermore, the average effect cannot simply be explained by attentional shifts but behaves as a primarily feedforward response property. Together, our obser- vations are most consistent with mechanistic models in which IT neuronal outputs are normalized by summed synaptic drive into IT or spiking activity within IT and suggest that normalization mechanisms previously revealed at earlier visual areas are operating through- out the ventral visual stream. |
Wieske van Zoest; Mieke Donk; Jan Theeuwes The role of stimulus-driven and goal-driven control in saccadic visual selection Journal Article Journal of Experimental Psychology: Human Perception and Performance, 30 (4), pp. 746–759, 2004. Abstract | Links | BibTeX @article{Zoest2004,
title = {The role of stimulus-driven and goal-driven control in saccadic visual selection},
author = {Wieske van Zoest and Mieke Donk and Jan Theeuwes},
doi = {10.1037/0096-1523.30.4.746},
year = {2004},
date = {2004-01-01},
journal = {Journal of Experimental Psychology: Human Perception and Performance},
volume = {30},
number = {4},
pages = {746--759},
abstract = {Four experiments were conducted to investigate the role of stimulus-driven and goal-driven control in saccadic eye movements. Participants were required to make a speeded saccade toward a predefined target presented concurrently with multiple nontargets and possibly 1 distractor. Target and distractor were either equally salient (Experiments 1 and 2) or not (Experiments 3 and 4). The results uniformly demonstrated that fast eye movements were completely stimulus driven, whereas slower eye movements were goal driven. These results are in line with neither a bottom-up account nor a top-down notion of visual selection. Instead, they indicate that visual selection is the outcome of 2 independent processes, one stimulus driven and the other goal driven, operating in different time windows.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Four experiments were conducted to investigate the role of stimulus-driven and goal-driven control in saccadic eye movements. Participants were required to make a speeded saccade toward a predefined target presented concurrently with multiple nontargets and possibly 1 distractor. Target and distractor were either equally salient (Experiments 1 and 2) or not (Experiments 3 and 4). The results uniformly demonstrated that fast eye movements were completely stimulus driven, whereas slower eye movements were goal driven. These results are in line with neither a bottom-up account nor a top-down notion of visual selection. Instead, they indicate that visual selection is the outcome of 2 independent processes, one stimulus driven and the other goal driven, operating in different time windows. |
Wieske van Zoest; Mieke Donk Saccadic target selection as a function of time Journal Article Spatial Vision, 19 (1), pp. 61–76, 2006. Abstract | Links | BibTeX @article{Zoest2006,
title = {Saccadic target selection as a function of time},
author = {Wieske van Zoest and Mieke Donk},
doi = {10.1007/s10530-005-5106-0},
year = {2006},
date = {2006-01-01},
journal = {Spatial Vision},
volume = {19},
number = {1},
pages = {61--76},
abstract = {Recent evidence indicates that stimulus-driven and goal-directed control of visual selection operate independently and in different time windows (van Zoest et al., 2004). The present study further investigates how eye movements are affected by stimulus-driven and goal-directed control. Observers were presented with search displays consisting of one target, multiple non-targets and one distractor element. The task of observers was to make a fast eye movement to a target immediately following the offset of a central fixation point, an event that either co-occurred with or soon followed the presentation of the search display. Distractor saliency and target-distractor similarity were independently manipulated. The results demonstrated that the effect of distractor saliency was transient and only present for the fastest eye movements, whereas the effect of target-distractor similarity was sustained and present in all but the fastest eye movements. The results support an independent timing account of visual selection.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Recent evidence indicates that stimulus-driven and goal-directed control of visual selection operate independently and in different time windows (van Zoest et al., 2004). The present study further investigates how eye movements are affected by stimulus-driven and goal-directed control. Observers were presented with search displays consisting of one target, multiple non-targets and one distractor element. The task of observers was to make a fast eye movement to a target immediately following the offset of a central fixation point, an event that either co-occurred with or soon followed the presentation of the search display. Distractor saliency and target-distractor similarity were independently manipulated. The results demonstrated that the effect of distractor saliency was transient and only present for the fastest eye movements, whereas the effect of target-distractor similarity was sustained and present in all but the fastest eye movements. The results support an independent timing account of visual selection. |
Wieske van Zoest; Mieke Donk Awareness of the saccade goal in oculomotor selection: Your eyes go before you know Journal Article Consciousness and Cognition, 19 (4), pp. 861–871, 2010. Abstract | Links | BibTeX @article{Zoest2010,
title = {Awareness of the saccade goal in oculomotor selection: Your eyes go before you know},
author = {Wieske van Zoest and Mieke Donk},
doi = {10.1016/j.concog.2010.04.001},
year = {2010},
date = {2010-01-01},
journal = {Consciousness and Cognition},
volume = {19},
number = {4},
pages = {861--871},
publisher = {Elsevier Inc.},
abstract = {The aim of the present study was to investigate how saccadic selection relates to people's awareness of the saliency and identity of a saccade goal. Observers were instructed to make an eye movement to either the most salient line segment (Experiment 1) or the only right-tilted element (Experiment 2) in a visual search display. The display was masked contingent on the first eye movement and after each trial observers indicated whether or not they had correctly selected the target. Whereas people's awareness concerning the saliency of the saccade goal was generally low, their awareness concerning the identity was high. Observers' awareness of the saccade goal was not related to saccadic performance. Whereas saccadic selection consistently varied as a function of saccade latency, people's awareness concerning the saliency or identity of the saccade goal did not. The results suggest that saccadic selection is primarily driven by subconscious processes.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The aim of the present study was to investigate how saccadic selection relates to people's awareness of the saliency and identity of a saccade goal. Observers were instructed to make an eye movement to either the most salient line segment (Experiment 1) or the only right-tilted element (Experiment 2) in a visual search display. The display was masked contingent on the first eye movement and after each trial observers indicated whether or not they had correctly selected the target. Whereas people's awareness concerning the saliency of the saccade goal was generally low, their awareness concerning the identity was high. Observers' awareness of the saccade goal was not related to saccadic performance. Whereas saccadic selection consistently varied as a function of saccade latency, people's awareness concerning the saliency or identity of the saccade goal did not. The results suggest that saccadic selection is primarily driven by subconscious processes. |
Wieske van Zoest; Amelia R Hunt Saccadic eye movements and perceptual judgments reveal a shared visual representation that is increasingly accurate over time Journal Article Vision Research, 51 (1), pp. 111–119, 2011. Abstract | Links | BibTeX @article{Zoest2011,
title = {Saccadic eye movements and perceptual judgments reveal a shared visual representation that is increasingly accurate over time},
author = {Wieske van Zoest and Amelia R Hunt},
doi = {10.1016/j.visres.2010.10.013},
year = {2011},
date = {2011-01-01},
journal = {Vision Research},
volume = {51},
number = {1},
pages = {111--119},
publisher = {Elsevier Ltd},
abstract = {Although there is evidence to suggest visual illusions affect perceptual judgments more than actions, many studies have failed to detect task-dependant dissociations. In two experiments we attempt to resolve the contradiction by exploring the time-course of visual illusion effects on both saccadic eye movements and perceptual judgments, using the Judd illusion. The results showed that, regardless of whether a saccadic response or a perceptual judgement was made, the illusory bias was larger when responses were based on less information, that is, when saccadic latencies were short, or display duration was brief. The time-course of the effect was similar for both the saccadic responses and perceptual judgements, suggesting that both modes may be driven by a shared visual representation. Changes in the strength of the illusion over time also highlight the importance of controlling for the latency of different response systems when evaluating possible dissociations between them.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Although there is evidence to suggest visual illusions affect perceptual judgments more than actions, many studies have failed to detect task-dependant dissociations. In two experiments we attempt to resolve the contradiction by exploring the time-course of visual illusion effects on both saccadic eye movements and perceptual judgments, using the Judd illusion. The results showed that, regardless of whether a saccadic response or a perceptual judgement was made, the illusory bias was larger when responses were based on less information, that is, when saccadic latencies were short, or display duration was brief. The time-course of the effect was similar for both the saccadic responses and perceptual judgements, suggesting that both modes may be driven by a shared visual representation. Changes in the strength of the illusion over time also highlight the importance of controlling for the latency of different response systems when evaluating possible dissociations between them. |
Wieske van Zoest; Mieke Donk; Stefan van der Stigchel Stimulus-salience and the time-course of saccade trajectory deviations Journal Article Journal of Vision, 12 (8), pp. 1–16, 2012. Abstract | Links | BibTeX @article{Zoest2012,
title = {Stimulus-salience and the time-course of saccade trajectory deviations},
author = {Wieske van Zoest and Mieke Donk and Stefan van der Stigchel},
doi = {10.1167/12.8.16},
year = {2012},
date = {2012-01-01},
journal = {Journal of Vision},
volume = {12},
number = {8},
pages = {1--16},
abstract = {The deviation of a saccade trajectory is a measure of the oculomotor competition evoked by a distractor. The aim of the present study was to investigate the impact of stimulus-salience on the time-course of saccade trajectory deviations to get a better insight into how stimulus-salience influences oculomotor competition over time. Two experiments were performed in which participants were required to make a vertical saccade to a target presented in an array of nontarget line elements and one additional distractor. The distractor varied in salience, where salience was defined by an orientation contrast relative to the surrounding nontargets. In Experiment 2, target-distractor similarity was additionally manipulated. In both Experiments 1 and 2, the results revealed that the eyes deviated towards the irrelevant distractor and did so more when the distractor was salient compared to when it was not salient. Critically, salience influenced performance only when people were fast to elicit an eye movement and had no effect when saccade latencies were long. Target-distractor similarity did not influence this pattern. These results show that the impact of salience in the visual system is transient.},
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The deviation of a saccade trajectory is a measure of the oculomotor competition evoked by a distractor. The aim of the present study was to investigate the impact of stimulus-salience on the time-course of saccade trajectory deviations to get a better insight into how stimulus-salience influences oculomotor competition over time. Two experiments were performed in which participants were required to make a vertical saccade to a target presented in an array of nontarget line elements and one additional distractor. The distractor varied in salience, where salience was defined by an orientation contrast relative to the surrounding nontargets. In Experiment 2, target-distractor similarity was additionally manipulated. In both Experiments 1 and 2, the results revealed that the eyes deviated towards the irrelevant distractor and did so more when the distractor was salient compared to when it was not salient. Critically, salience influenced performance only when people were fast to elicit an eye movement and had no effect when saccade latencies were long. Target-distractor similarity did not influence this pattern. These results show that the impact of salience in the visual system is transient. |
Wieske van Zoest; Dirk Kerzel The effects of saliency on manual reach trajectories and reach target selection Journal Article Vision Research, 113 , pp. 179–187, 2015. Abstract | Links | BibTeX @article{Zoest2015,
title = {The effects of saliency on manual reach trajectories and reach target selection},
author = {Wieske van Zoest and Dirk Kerzel},
doi = {10.1016/j.visres.2014.11.015},
year = {2015},
date = {2015-01-01},
journal = {Vision Research},
volume = {113},
pages = {179--187},
publisher = {Elsevier Ltd},
abstract = {Reaching trajectories curve toward salient distractors, reflecting the competing activation of reach plans toward target and distractor stimuli. We investigated whether the relative saliency of target and distractor influenced the curvature of the movement and the selection of the final endpoint of the reach. Participants were asked to reach a bar tilted to the right in a context of gray vertical bars. A bar tilted to the left served as distractor. Relative stimulus saliency was varied via color: either the distractor was red and the target was gray, or vice versa. Throughout, we observed that reach trajectories deviated toward the distractor. Surprisingly, relative saliency had no effect on the curvature of reach trajectories. Moreover, when we increased time pressure in separate experiments and analyzed the curvature as a function of reaction time, no influence of relative stimulus saliency was found, not even for the fastest reaction times. If anything, curvature decreased with strong time pressure. In contrast, reach target selection under strong time pressure was influenced by relative saliency: reaches with short reaction times were likely to go to the red distractor. The time course of reach target selection was comparable to saccadic target selection. Implications for the neural basis of trajectory deviations and target selection in manual and eye movements are discussed.},
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pubstate = {published},
tppubtype = {article}
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Reaching trajectories curve toward salient distractors, reflecting the competing activation of reach plans toward target and distractor stimuli. We investigated whether the relative saliency of target and distractor influenced the curvature of the movement and the selection of the final endpoint of the reach. Participants were asked to reach a bar tilted to the right in a context of gray vertical bars. A bar tilted to the left served as distractor. Relative stimulus saliency was varied via color: either the distractor was red and the target was gray, or vice versa. Throughout, we observed that reach trajectories deviated toward the distractor. Surprisingly, relative saliency had no effect on the curvature of reach trajectories. Moreover, when we increased time pressure in separate experiments and analyzed the curvature as a function of reaction time, no influence of relative stimulus saliency was found, not even for the fastest reaction times. If anything, curvature decreased with strong time pressure. In contrast, reach target selection under strong time pressure was influenced by relative saliency: reaches with short reaction times were likely to go to the red distractor. The time course of reach target selection was comparable to saccadic target selection. Implications for the neural basis of trajectory deviations and target selection in manual and eye movements are discussed. |
Wieske van Zoest; Benedetta Heimler; Francesco Pavani The oculomotor salience of flicker, apparent motion and continuous motion in saccade trajectories Journal Article Experimental Brain Research, 235 , pp. 181–191, 2017. Abstract | Links | BibTeX @article{Zoest2017,
title = {The oculomotor salience of flicker, apparent motion and continuous motion in saccade trajectories},
author = {Wieske van Zoest and Benedetta Heimler and Francesco Pavani},
doi = {10.1007/s00221-016-4779-1},
year = {2017},
date = {2017-01-01},
journal = {Experimental Brain Research},
volume = {235},
pages = {181--191},
publisher = {Springer Berlin Heidelberg},
abstract = {The aim of the present study was to investigate the impact of dynamic distractors on the time-course of oculomotor selection using saccade trajectory deviations. Participants were instructed to make a speeded eye move- ment (pro-saccade) to a target presented above or below the fixation point while an irrelevant distractor was presented. Four types of distractors were varied within participants: (1) static, (2) flicker, (3) rotating apparent motion and (4) continuous motion. The eccentricity of the distractor was varied between participants. The results showed that sac- cadic trajectories curved towards distractors presented near the vertical midline; no reliable deviation was found for distractors presented further away from the vertical mid- line. Differences between the flickering and rotating dis- tractor were found when distractor eccentricity was small and these specific effects developed over time such that there was a clear differentiation between saccadic deviation based on apparent motion for long-latency saccades, but not short-latency saccades. The present results suggest that the influence on performance of apparent motion stimuli is relatively delayed and acts in a more sustained manner compared to the influence of salient static, flickering and continuous moving stimuli.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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The aim of the present study was to investigate the impact of dynamic distractors on the time-course of oculomotor selection using saccade trajectory deviations. Participants were instructed to make a speeded eye move- ment (pro-saccade) to a target presented above or below the fixation point while an irrelevant distractor was presented. Four types of distractors were varied within participants: (1) static, (2) flicker, (3) rotating apparent motion and (4) continuous motion. The eccentricity of the distractor was varied between participants. The results showed that sac- cadic trajectories curved towards distractors presented near the vertical midline; no reliable deviation was found for distractors presented further away from the vertical mid- line. Differences between the flickering and rotating dis- tractor were found when distractor eccentricity was small and these specific effects developed over time such that there was a clear differentiation between saccadic deviation based on apparent motion for long-latency saccades, but not short-latency saccades. The present results suggest that the influence on performance of apparent motion stimuli is relatively delayed and acts in a more sustained manner compared to the influence of salient static, flickering and continuous moving stimuli. |
Regine Zopf; Marina Butko; Alexandra Woolgar; Mark A Williams; Anina N Rich Representing the location of manipulable objects in shape-selective occipitotemporal cortex: Beyond retinotopic reference frames? Journal Article Cortex, 106 , pp. 132–150, 2018. Abstract | Links | BibTeX @article{Zopf2018,
title = {Representing the location of manipulable objects in shape-selective occipitotemporal cortex: Beyond retinotopic reference frames?},
author = {Regine Zopf and Marina Butko and Alexandra Woolgar and Mark A Williams and Anina N Rich},
doi = {10.1016/j.cortex.2018.05.009},
year = {2018},
date = {2018-01-01},
journal = {Cortex},
volume = {106},
pages = {132--150},
abstract = {When interacting with objects, we have to represent their location relative to our bodies. To facilitate bodily reactions, location may be encoded in the brain not just with respect to the retina (retinotopic reference frame), but also in relation to the head, trunk or arm (collectively spatiotopic reference frames). While spatiotopic reference frames for location encoding can be found in brain areas for action planning, such as parietal areas, there is debate about the existence of spatiotopic reference frames in higher-level occipitotemporal visual areas. In an extensive multi-voxel pattern analysis (MVPA) fMRI study using faces, headless bodies and scenes stimuli, Golomb and Kanwisher (2012) did not find evidence for spatiotopic reference frames in shape-selective occipitotemporal cortex. This finding is important for theories of how stimulus location is encoded in the brain. It is possible, however, that their failure to find spatiotopic reference frames is related to their stimuli: we typically do not manipulate faces, headless bodies or scenes. It is plausible that we only represent body-centred location when viewing objects that are typically manipulated. Here, we tested for object location encoding in shape-selective occipitotemporal cortex using manipulable object stimuli (balls and cups) in a MVPA fMRI study. We employed Bayesian analyses to determine sample size and evaluate the sensitivity of our data to test the hypothesis that location can be encoded in a spatiotopic reference frame in shape-selective occipitotemporal cortex over the null hypothesis of no spatiotopic location encoding. We found strong evidence for retinotopic location encoding consistent with previous findings that retinotopic reference frames are common neural representations of object location. In contrast, when testing for spatiotopic encoding, we found evidence that object location information for small manipulable objects is not decodable in relation to the body in shape-selective occipitotemporal cortex. Post-hoc exploratory analyses suggested that spatiotopic aspects might modulate retinotopic location encoding.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
When interacting with objects, we have to represent their location relative to our bodies. To facilitate bodily reactions, location may be encoded in the brain not just with respect to the retina (retinotopic reference frame), but also in relation to the head, trunk or arm (collectively spatiotopic reference frames). While spatiotopic reference frames for location encoding can be found in brain areas for action planning, such as parietal areas, there is debate about the existence of spatiotopic reference frames in higher-level occipitotemporal visual areas. In an extensive multi-voxel pattern analysis (MVPA) fMRI study using faces, headless bodies and scenes stimuli, Golomb and Kanwisher (2012) did not find evidence for spatiotopic reference frames in shape-selective occipitotemporal cortex. This finding is important for theories of how stimulus location is encoded in the brain. It is possible, however, that their failure to find spatiotopic reference frames is related to their stimuli: we typically do not manipulate faces, headless bodies or scenes. It is plausible that we only represent body-centred location when viewing objects that are typically manipulated. Here, we tested for object location encoding in shape-selective occipitotemporal cortex using manipulable object stimuli (balls and cups) in a MVPA fMRI study. We employed Bayesian analyses to determine sample size and evaluate the sensitivity of our data to test the hypothesis that location can be encoded in a spatiotopic reference frame in shape-selective occipitotemporal cortex over the null hypothesis of no spatiotopic location encoding. We found strong evidence for retinotopic location encoding consistent with previous findings that retinotopic reference frames are common neural representations of object location. In contrast, when testing for spatiotopic encoding, we found evidence that object location information for small manipulable objects is not decodable in relation to the body in shape-selective occipitotemporal cortex. Post-hoc exploratory analyses suggested that spatiotopic aspects might modulate retinotopic location encoding. |
Heng Zou; Hermann J Muller; Zhuanghua Shi Non-spatial sounds regulate eye movements and enhance visual search Journal Article Journal of Vision, 12 (5), pp. 2–2, 2012. Abstract | Links | BibTeX @article{Zou2012,
title = {Non-spatial sounds regulate eye movements and enhance visual search},
author = {Heng Zou and Hermann J Muller and Zhuanghua Shi},
doi = {10.1167/12.5.2},
year = {2012},
date = {2012-01-01},
journal = {Journal of Vision},
volume = {12},
number = {5},
pages = {2--2},
abstract = {Spatially uninformative sounds can enhance visual search when the sounds are synchronized with color changes of the visual target, a phenomenon referred to as "pip-and-pop" effect (van der Burg, Olivers, Bronkhorst, & Theeuwes, 2008). The present study investigated the relationship of this effect to changes in oculomotor scanning behavior induced by the sounds. The results revealed sound events to increase fixation durations upon their occurrence and to decrease the mean number of saccades. More specifically, spatially uninformative sounds facilitated the orientation of ocular scanning away from already scanned display regions not containing a target (Experiment 1) and enhanced search performance even on target-absent trials (Experiment 2). Facilitation was also observed when the sounds were presented 100 ms prior to the target or at random (Experiment 3). These findings suggest that non-spatial sounds cause a general freezing effect on oculomotor scanning behavior, an effect which in turn benefits visual search performance by temporally and spatially extended information sampling.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Spatially uninformative sounds can enhance visual search when the sounds are synchronized with color changes of the visual target, a phenomenon referred to as "pip-and-pop" effect (van der Burg, Olivers, Bronkhorst, & Theeuwes, 2008). The present study investigated the relationship of this effect to changes in oculomotor scanning behavior induced by the sounds. The results revealed sound events to increase fixation durations upon their occurrence and to decrease the mean number of saccades. More specifically, spatially uninformative sounds facilitated the orientation of ocular scanning away from already scanned display regions not containing a target (Experiment 1) and enhanced search performance even on target-absent trials (Experiment 2). Facilitation was also observed when the sounds were presented 100 ms prior to the target or at random (Experiment 3). These findings suggest that non-spatial sounds cause a general freezing effect on oculomotor scanning behavior, an effect which in turn benefits visual search performance by temporally and spatially extended information sampling. |
Sandrine Zufferey; Willem Mak; Liesbeth Degand; Ted Sanders Advanced learners' comprehension of discourse connectives: The role of L1 transfer across on-line and off-line tasks Journal Article Second Language Research, 31 (3), pp. 389–411, 2015. Abstract | Links | BibTeX @article{Zufferey2015,
title = {Advanced learners' comprehension of discourse connectives: The role of L1 transfer across on-line and off-line tasks},
author = {Sandrine Zufferey and Willem Mak and Liesbeth Degand and Ted Sanders},
doi = {10.1177/0267658315573349},
year = {2015},
date = {2015-01-01},
journal = {Second Language Research},
volume = {31},
number = {3},
pages = {389--411},
abstract = {Discourse connectives are important indicators of textual coherence, and mastering them is an essential part of acquiring a language. In this article, we compare advanced learners' sensitivity to the meaning conveyed by connectives in an off-line grammaticality judgment task and an on-line reading experiment using eye-tracking. We also assess the influence of first language (L1) transfer by comparing learners' comprehension of two non-native-like semantic uses of connectives in English, often produced by learners due to transfer from French and Dutch. Our results indicate that in an off-line task transfer is an important factor accounting for French-and Dutch-speaking learners' non-native-like comprehension of connectives. During on-line processing, however, learners are as sensitive as native speakers to the meaning conveyed by connectives. These results raise intriguing questions regarding explicit vs. implicit knowledge in language learners.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Discourse connectives are important indicators of textual coherence, and mastering them is an essential part of acquiring a language. In this article, we compare advanced learners' sensitivity to the meaning conveyed by connectives in an off-line grammaticality judgment task and an on-line reading experiment using eye-tracking. We also assess the influence of first language (L1) transfer by comparing learners' comprehension of two non-native-like semantic uses of connectives in English, often produced by learners due to transfer from French and Dutch. Our results indicate that in an off-line task transfer is an important factor accounting for French-and Dutch-speaking learners' non-native-like comprehension of connectives. During on-line processing, however, learners are as sensitive as native speakers to the meaning conveyed by connectives. These results raise intriguing questions regarding explicit vs. implicit knowledge in language learners. |
Wietske Zuiderbaan; Ben M Harvey; Serge O Dumoulin Modeling center – surround configurations in population receptive fields using fMRI Journal Article Journal of Vision, 12 (3), pp. 1–15, 2012. Abstract | Links | BibTeX @article{Zuiderbaan2012,
title = {Modeling center – surround configurations in population receptive fields using fMRI},
author = {Wietske Zuiderbaan and Ben M Harvey and Serge O Dumoulin},
doi = {10.1167/12.3.10.Introduction},
year = {2012},
date = {2012-01-01},
journal = {Journal of Vision},
volume = {12},
number = {3},
pages = {1--15},
abstract = {Antagonistic center–surround configurations are a central organizational principle of our visual system. In visual cortex, stimulation outside the classical receptive field can decrease neural activity and also decrease functional Magnetic Resonance Imaging (fMRI) signal amplitudes. Decreased fMRI amplitudes below baseline—0% contrast—are often referred to as “negative” responses. Using neural model-based fMRI data analyses, we can estimate the region of visual space to which each cortical location responds, i.e., the population receptive field (pRF). Current models of the pRF do not account for a center–surround organization or negative fMRI responses. Here, we extend the pRF model by adding surround suppression. Where the conventional model uses a circular symmetric Gaussian function to describe the pRF, the new model uses a circular symmetric difference-of-Gaussians (DoG) function. The DoG model allows the pRF analysis to capture fMRI signals below baseline and surround suppression. Comparing the fits of the models, an increased variance explained is found for the DoG model. This improvement was predominantly present in V1/2/3 and decreased in later visual areas. The improvement of the fits was particularly striking in the parts of the fMRI signal below baseline. Estimates for the surround size of the pRF show an increase with eccentricity and over visual areas V1/2/3. For the suppression index, which is based on the ratio between the volumes of both Gaussians, we show a decrease over visual areas V1 and V2. Using non-invasive fMRI techniques, this method gives the possibility to examine assumptions about center–surround receptive fields in human subjects.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Antagonistic center–surround configurations are a central organizational principle of our visual system. In visual cortex, stimulation outside the classical receptive field can decrease neural activity and also decrease functional Magnetic Resonance Imaging (fMRI) signal amplitudes. Decreased fMRI amplitudes below baseline—0% contrast—are often referred to as “negative” responses. Using neural model-based fMRI data analyses, we can estimate the region of visual space to which each cortical location responds, i.e., the population receptive field (pRF). Current models of the pRF do not account for a center–surround organization or negative fMRI responses. Here, we extend the pRF model by adding surround suppression. Where the conventional model uses a circular symmetric Gaussian function to describe the pRF, the new model uses a circular symmetric difference-of-Gaussians (DoG) function. The DoG model allows the pRF analysis to capture fMRI signals below baseline and surround suppression. Comparing the fits of the models, an increased variance explained is found for the DoG model. This improvement was predominantly present in V1/2/3 and decreased in later visual areas. The improvement of the fits was particularly striking in the parts of the fMRI signal below baseline. Estimates for the surround size of the pRF show an increase with eccentricity and over visual areas V1/2/3. For the suppression index, which is based on the ratio between the volumes of both Gaussians, we show a decrease over visual areas V1 and V2. Using non-invasive fMRI techniques, this method gives the possibility to examine assumptions about center–surround receptive fields in human subjects. |
Jan Zwickel; Hermann J Müller Eye movements as a means to evaluate and improve robots Journal Article International Journal of Social Robotics, 1 (4), pp. 357–366, 2009. Abstract | Links | BibTeX @article{Zwickel2009,
title = {Eye movements as a means to evaluate and improve robots},
author = {Jan Zwickel and Hermann J Müller},
doi = {10.1007/s12369-009-0033-3},
year = {2009},
date = {2009-01-01},
journal = {International Journal of Social Robotics},
volume = {1},
number = {4},
pages = {357--366},
abstract = {Abstract With an increase in their capabilities, robots start to play a role in everyday settings. This necessitates a step from a robot-centered (i.e., teaching humans to adapt to robots) to a more human-centered approach (where robots integrate naturally into human activities). Achieving this will increase the effectiveness of robot usage (e.g., shortening the time required for learning), reduce errors, and increase user acceptance. Robotic camera control will play an important role for a more natural and easier-to-interpret behavior, owing to the central importance of gaze in human communication. This study is intended to provide a first step towards improving camera control by a better understanding of human gaze behavior in social situations. To this end, we registered the eye movements of humans watching different types of movies. In all movies, the same two triangles moved around in a self-propelled fashion. However, crucially, some of the movies elicited the attribution of mental states to the triangles, while others did not. This permitted us to directly distinguish eye movement patterns relating to the attribution of mental states in (perceived) social situations, from the patterns in non-social situations. We argue that a better understanding of what characterizes human gaze patterns in social situations will help shape robotic behavior, make it more natural for humans to communicate with robots, and establish joint attention (to certain objects) between humans and robots. In addition, a better understanding of human gaze in social situations will provide a measure for evaluating whether robots are perceived as social agents rather than non-intentional machines. This could help decide which behaviors a robot should display in order to be perceived as a social interaction partner.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Abstract With an increase in their capabilities, robots start to play a role in everyday settings. This necessitates a step from a robot-centered (i.e., teaching humans to adapt to robots) to a more human-centered approach (where robots integrate naturally into human activities). Achieving this will increase the effectiveness of robot usage (e.g., shortening the time required for learning), reduce errors, and increase user acceptance. Robotic camera control will play an important role for a more natural and easier-to-interpret behavior, owing to the central importance of gaze in human communication. This study is intended to provide a first step towards improving camera control by a better understanding of human gaze behavior in social situations. To this end, we registered the eye movements of humans watching different types of movies. In all movies, the same two triangles moved around in a self-propelled fashion. However, crucially, some of the movies elicited the attribution of mental states to the triangles, while others did not. This permitted us to directly distinguish eye movement patterns relating to the attribution of mental states in (perceived) social situations, from the patterns in non-social situations. We argue that a better understanding of what characterizes human gaze patterns in social situations will help shape robotic behavior, make it more natural for humans to communicate with robots, and establish joint attention (to certain objects) between humans and robots. In addition, a better understanding of human gaze in social situations will provide a measure for evaluating whether robots are perceived as social agents rather than non-intentional machines. This could help decide which behaviors a robot should display in order to be perceived as a social interaction partner. |
Jan Zwickel; L H Vö Melissa How the presence of persons biases eye movements Journal Article Psychonomic Bulletin & Review, 17 (2), pp. 257–262, 2010. Abstract | Links | BibTeX @article{Zwickel2010,
title = {How the presence of persons biases eye movements},
author = {Jan Zwickel and L H Vö Melissa},
doi = {10.3758/PBR.17.2.257},
year = {2010},
date = {2010-01-01},
journal = {Psychonomic Bulletin & Review},
volume = {17},
number = {2},
pages = {257--262},
abstract = {We investigated modulation of gaze behavior of observers viewing complex scenes that included a person. To assess spontaneous orientation-following, and in contrast to earlier studies, we did not make the person salient via instruction or low-level saliency. Still, objects that were referred to by the orientation of the person were visited earlier, more often, and longer than when they were not referred to. Analysis of fixation sequences showed that the number of saccades to the cued and uncued objects differed only for saccades that started from the head region, but not for saccades starting from a control object or from a body region. We therefore argue that viewing a person leads to an increase in spontaneous following of the person's viewing direction even when the person plays no role in scene understanding and is not made prominent.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We investigated modulation of gaze behavior of observers viewing complex scenes that included a person. To assess spontaneous orientation-following, and in contrast to earlier studies, we did not make the person salient via instruction or low-level saliency. Still, objects that were referred to by the orientation of the person were visited earlier, more often, and longer than when they were not referred to. Analysis of fixation sequences showed that the number of saccades to the cued and uncued objects differed only for saccades that started from the head region, but not for saccades starting from a control object or from a body region. We therefore argue that viewing a person leads to an increase in spontaneous following of the person's viewing direction even when the person plays no role in scene understanding and is not made prominent. |
Jan Zwickel; Mathias Hegele; Marc Grosjean Ocular tracking of biological and nonbiological motion: The effect of instructed agency Journal Article Psychonomic Bulletin & Review, 19 (1), pp. 52–57, 2012. Abstract | Links | BibTeX @article{Zwickel2012,
title = {Ocular tracking of biological and nonbiological motion: The effect of instructed agency},
author = {Jan Zwickel and Mathias Hegele and Marc Grosjean},
doi = {10.3758/s13423-011-0193-7},
year = {2012},
date = {2012-01-01},
journal = {Psychonomic Bulletin & Review},
volume = {19},
number = {1},
pages = {52--57},
abstract = {Recent findings suggest that visuomotor performance is modulated by people's beliefs about the agency (e.g., animate vs. inanimate) behind the events they perceive. This study investigated the effect of instructed agency on ocular tracking of point-light motions with biological and nonbiological velocity profiles. The motions followed either a relatively simple (ellipse) or a more complex (scribble) trajectory, and agency was manipulated by informing the participants that the motions they saw were either human or computer generated. In line with previous findings, tracking performance was better for biological than for nonbiological motions, and this effect was particularly pronounced for the simpler (elliptical) motions. The biological advantage was also larger for the human than for the computer instruction condition, but only for a measure that captured the predictive component of smooth pursuit. These results suggest that ocular tracking is influenced by the internal forward model people choose to adopt.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Recent findings suggest that visuomotor performance is modulated by people's beliefs about the agency (e.g., animate vs. inanimate) behind the events they perceive. This study investigated the effect of instructed agency on ocular tracking of point-light motions with biological and nonbiological velocity profiles. The motions followed either a relatively simple (ellipse) or a more complex (scribble) trajectory, and agency was manipulated by informing the participants that the motions they saw were either human or computer generated. In line with previous findings, tracking performance was better for biological than for nonbiological motions, and this effect was particularly pronounced for the simpler (elliptical) motions. The biological advantage was also larger for the human than for the computer instruction condition, but only for a measure that captured the predictive component of smooth pursuit. These results suggest that ocular tracking is influenced by the internal forward model people choose to adopt. |
Ariel Zylberberg; Pablo Barttfeld; Mariano Sigman The construction of confidence in a perceptual decision Journal Article Frontiers in Integrative Neuroscience, 6 (September), pp. 1–10, 2012. Abstract | Links | BibTeX @article{Zylberberg2012,
title = {The construction of confidence in a perceptual decision},
author = {Ariel Zylberberg and Pablo Barttfeld and Mariano Sigman},
doi = {10.3389/fnint.2012.00079},
year = {2012},
date = {2012-01-01},
journal = {Frontiers in Integrative Neuroscience},
volume = {6},
number = {September},
pages = {1--10},
abstract = {Decision-making involves the selection of one out of many possible courses of action. A decision may bear on other decisions, as when humans seek a second medical opinion before undergoing a risky surgical intervention. These "meta-decisions" are mediated by confidence judgments-the degree to which decision-makers consider that a choice is likely to be correct. We studied how subjective confidence is constructed from noisy sensory evidence. The psychophysical kernels used to convert sensory information into choice and confidence decisions were precisely reconstructed measuring the impact of small fluctuations in sensory input. This is shown in two independent experiments in which human participants made a decision about the direction of motion of a set of randomly moving dots, or compared the brightness of a group of fluctuating bars, followed by a confidence report. The results of both experiments converged to show that: (1) confidence was influenced by evidence during a short window of time at the initial moments of the decision, and (2) confidence was influenced by evidence for the selected choice but was virtually blind to evidence for the non-selected choice. Our findings challenge classical models of subjective confidence-which posit that the difference of evidence in favor of each choice is the seed of the confidence signal.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Decision-making involves the selection of one out of many possible courses of action. A decision may bear on other decisions, as when humans seek a second medical opinion before undergoing a risky surgical intervention. These "meta-decisions" are mediated by confidence judgments-the degree to which decision-makers consider that a choice is likely to be correct. We studied how subjective confidence is constructed from noisy sensory evidence. The psychophysical kernels used to convert sensory information into choice and confidence decisions were precisely reconstructed measuring the impact of small fluctuations in sensory input. This is shown in two independent experiments in which human participants made a decision about the direction of motion of a set of randomly moving dots, or compared the brightness of a group of fluctuating bars, followed by a confidence report. The results of both experiments converged to show that: (1) confidence was influenced by evidence during a short window of time at the initial moments of the decision, and (2) confidence was influenced by evidence for the selected choice but was virtually blind to evidence for the non-selected choice. Our findings challenge classical models of subjective confidence-which posit that the difference of evidence in favor of each choice is the seed of the confidence signal. |
Ariel Zylberberg; Manuel Oliva; Mariano Sigman Pupil dilation: A fingerprint of temporal selection during the "Attentional Blink" Journal Article Frontiers in Psychology, 3 (AUG), pp. 1–6, 2012. Abstract | Links | BibTeX @article{Zylberberg2012a,
title = {Pupil dilation: A fingerprint of temporal selection during the "Attentional Blink"},
author = {Ariel Zylberberg and Manuel Oliva and Mariano Sigman},
doi = {10.3389/fpsyg.2012.00316},
year = {2012},
date = {2012-01-01},
journal = {Frontiers in Psychology},
volume = {3},
number = {AUG},
pages = {1--6},
abstract = {Pupil dilation indexes cognitive events of behavioral relevance, like the storage of information to memory and the deployment of attention. Yet, given the slow temporal response of the pupil dilation, it is not known from previous studies whether the pupil can index cognitive events in the short time scale of ∼100 ms. Here we measured the size of the pupil in the Attentional Blink (AB) experiment, a classic demonstration of attentional limitations in processing rapidly presented stimuli. In the AB, two targets embedded in a sequence have to be reported and the second stimulus is often missed if presented between 200 and 500 ms after the first. We show that pupil dilation can be used as a marker of cognitive processing in AB, revealing both the timing and amount of cognitive processing. Specifically, we found that in the time range where the AB is known to occur: (i) the pupil dilation was delayed, mimicking the pattern of response times in the Psychological Refractory Period (PRP) paradigm, (ii) the amplitude of the pupil was reduced relative to that of larger lags, even for correctly identified targets, and (iii) the amplitude of the pupil was smaller for missed than for correctly reported targets. These results support two-stage theories of the Attentional Blink where a second processing stage is delayed inside the interference regime, and indicate that the pupil dilation can be used as a marker of cognitive processing in the time scale of ∼100 ms. Furthermore, given the known relation between the pupil dilation and the activity of the locus coeruleus, our results also support theories that link the serial stage to the action of a specific neuromodulator, norepinephrine.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Pupil dilation indexes cognitive events of behavioral relevance, like the storage of information to memory and the deployment of attention. Yet, given the slow temporal response of the pupil dilation, it is not known from previous studies whether the pupil can index cognitive events in the short time scale of ∼100 ms. Here we measured the size of the pupil in the Attentional Blink (AB) experiment, a classic demonstration of attentional limitations in processing rapidly presented stimuli. In the AB, two targets embedded in a sequence have to be reported and the second stimulus is often missed if presented between 200 and 500 ms after the first. We show that pupil dilation can be used as a marker of cognitive processing in AB, revealing both the timing and amount of cognitive processing. Specifically, we found that in the time range where the AB is known to occur: (i) the pupil dilation was delayed, mimicking the pattern of response times in the Psychological Refractory Period (PRP) paradigm, (ii) the amplitude of the pupil was reduced relative to that of larger lags, even for correctly identified targets, and (iii) the amplitude of the pupil was smaller for missed than for correctly reported targets. These results support two-stage theories of the Attentional Blink where a second processing stage is delayed inside the interference regime, and indicate that the pupil dilation can be used as a marker of cognitive processing in the time scale of ∼100 ms. Furthermore, given the known relation between the pupil dilation and the activity of the locus coeruleus, our results also support theories that link the serial stage to the action of a specific neuromodulator, norepinephrine. |
Ariel Zylberberg; Daniel M Wolpert; Michael N Shadlen Counterfactual reasoning underlies the learning of priors in decision making Journal Article Neuron, 99 (5), pp. 1083–1097, 2018. Abstract | Links | BibTeX @article{Zylberberg2018,
title = {Counterfactual reasoning underlies the learning of priors in decision making},
author = {Ariel Zylberberg and Daniel M Wolpert and Michael N Shadlen},
doi = {10.1016/j.neuron.2018.07.035},
year = {2018},
date = {2018-01-01},
journal = {Neuron},
volume = {99},
number = {5},
pages = {1083--1097},
publisher = {The Authors},
abstract = {Accurate decisions require knowledge of prior probabilities (e.g., prevalence or base rate), but it is unclear how prior probabilities are learned in the absence of a teacher. We hypothesized that humans could learn base rates from experience making decisions, even without feedback. Participants made difficult decisions about the direction of dynamic random dot motion. Across blocks of 15–42 trials, the base rate favoring left or right varied. Participants were not informed of the base rate or choice accuracy, yet they gradually biased their choices and thereby increased accuracy and confidence in their decisions. They achieved this by updating knowledge of base rate after each decision, using a counterfactual representation of confidence that simulates a neutral prior. The strategy is consistent with Bayesian updating of belief and suggests that humans represent both true confidence, which incorporates the evolving belief of the prior, and counterfactual confidence, which discounts the prior. Zylberberg et al. show that human decision makers can learn environmental biases from sequences of difficult decisions, without feedback about accuracy, by calculating the belief that the decisions would have been correct in an unbiased environment—a form of counterfactual confidence.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Accurate decisions require knowledge of prior probabilities (e.g., prevalence or base rate), but it is unclear how prior probabilities are learned in the absence of a teacher. We hypothesized that humans could learn base rates from experience making decisions, even without feedback. Participants made difficult decisions about the direction of dynamic random dot motion. Across blocks of 15–42 trials, the base rate favoring left or right varied. Participants were not informed of the base rate or choice accuracy, yet they gradually biased their choices and thereby increased accuracy and confidence in their decisions. They achieved this by updating knowledge of base rate after each decision, using a counterfactual representation of confidence that simulates a neutral prior. The strategy is consistent with Bayesian updating of belief and suggests that humans represent both true confidence, which incorporates the evolving belief of the prior, and counterfactual confidence, which discounts the prior. Zylberberg et al. show that human decision makers can learn environmental biases from sequences of difficult decisions, without feedback about accuracy, by calculating the belief that the decisions would have been correct in an unbiased environment—a form of counterfactual confidence. |
