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2015 |
Sandrine Zufferey; Willem M. Mak; Liesbeth Degand; Ted J. M. Sanders Advanced learners' comprehension of discourse connectives: The role of L1 transfer across on-line and off-line tasks Journal Article In: Second Language Research, vol. 31, no. 3, pp. 389–411, 2015. @article{Zufferey2015, 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. |
Yoshiko Yabe; Melvyn A. Goodale Time flies when we intend to act: Temporal distortion in a Go/No-Go task Journal Article In: Journal of Neuroscience, vol. 35, no. 12, pp. 5023–5029, 2015. @article{Yabe2015, Although many of our actions are triggered by sensory events, almost nothing is known about our perception of the timing of those sensory events. Here we show that, when people react to a sudden visual stimulus that triggers an action, that stimulus is perceived to occur later than an identical stimulus that does not trigger an action. In our experiments, participants fixated the center of a clock face with a rotating second hand. When the clock changed color, they were required to make a motor response and then to report the position of the second hand at the moment the clock changed color. In Experiment 1, in which participants made a target-directed saccade, the color change was perceived to occur 59 ms later than when they maintained fixation. In Experiment 2, in which we used a go/no-go paradigm, this temporal distortion was observed even when participants were required to cancel a prepared saccade. Finally, in Exper-iment 3, the same distortion in perceived time was observed for both go and no-go trials in a manual task in which no eye movements were required. These results suggest that, when a visual stimulus triggers an action, it is perceived to occur significantly later than an identical stimulus unrelated to action. Moreover, this temporal distortion appears to be related not to the execution of the action (or its effect) but rather to the programming of the action. In short, there seems to be a temporal binding between a triggering event and the triggered action |
Ming Yan Visually complex foveal words increase the amount of parafoveal information acquired Journal Article In: Vision Research, vol. 111, no. Part A, pp. 91–96, 2015. @article{Yan2015, This study investigates the effect of foveal load (i.e., processing difficulty of currently fixated words) on parafoveal information processing. Contrary to the commonly accepted view that high foveal load leads to reduced parafoveal processing efficiency, results of the present study showed that increasing foveal visual (but not linguistic) processing load actually increased the amount of parafoveal information acquired, presumably due to the fact that longer fixation duration on the pretarget word provided more time for parafoveal processing of the target word. It is therefore proposed in the present study that foveal linguistic processing load is not the only factor that determines parafoveal processing; preview time (afforded by foveal word visual processing load) may jointly influence parafoveal processing. |
Ming Yan; Reinhold Kliegl Perceptual Span Depends on Font Size During the Reading of Chinese Sentences Journal Article In: Journal of Experimental Psychology: Learning, Memory, and Cognition, vol. 41, no. 1, pp. 209–219, 2015. @article{Yan2015a, The present study explored the perceptual span (i.e., the physical extent of an area from which useful visual information is extracted during a single fixation) during the reading of Chinese sentences in 2 experiments. In Experiment 1, we tested whether the rightward span can go beyond 3 characters when visually similar masks were used. Results showed that Chinese readers needed at least 4 characters to the right of fixation to maintain a normal reading behavior when visually similar masks were used and when characters were displayed in small fonts, indicating that the span is dynamically influenced by masking materials. In Experiments 2 and 3, we asked whether the perceptual span varies as a function of font size in spaced (German) and unspaced (Chinese) scripts. Results clearly suggest perceptual span depends on font size in Chinese, but we failed to find such evidence for German. We propose that the perceptual span in Chinese is flexible; it is strongly constrained by its language-specific properties such as high information density and lack of word spacing. Implications for saccade-target selection during the reading of Chinese sentences are discussed. |
Ming Yan; Jinger Pan; Nathalie N. Bélanger; Hua Shu Chinese deaf readers have early access to parafoveal semantics Journal Article In: Journal of Experimental Psychology: Learning, Memory, and Cognition, vol. 41, no. 1, pp. 254–261, 2015. @article{Yan2015c, In the present study, we manipulated different types of information available in the parafovea during the reading of Chinese sentences and examined how deaf readers make use of the parafoveal information. Results clearly indicate that although the reading-level matched hearing readers make greater use of orthographic information in the parafovea, parafoveal semantic information is obtained earlier among the deaf readers. In addition, a phonological preview benefit effect was found for the better deaf readers (relative to less-skilled deaf readers), although we also provide an alternative explanation for this effect. Providing evidence that Chinese deaf readers have higher efficiency when processing parafoveal semantics, the study indicates flexibility across individuals in the mechanisms underlying word recognition adapting to the inputs available in the linguistic environment. |
Ming Yan; Werner Sommer Parafoveal-on-foveal effects of emotional word semantics in reading chinese sentences: Evidence from eye movements Journal Article In: Journal of Experimental Psychology: Learning, Memory, and Cognition, vol. 41, no. 4, pp. 1237–1243, 2015. @article{Yan2015b, Despite the well-known influence of emotional meaning on cognition, relatively less is known about its effects on reading behavior. We investigated whether fixation behavior during the reading of Chinese sentences is influenced by emotional word meaning in the parafovea. Two-character target words embedded into the same sentence frames provided emotionally positive, negative, or neutral contents. Fixation durations on neutral pretarget words were prolonged for positive parafoveal words and for highly frequent negative parafoveal words. In addition, fixation durations on foveal emotional words were shorter than those on neutral words. We also found that the role of emotional words varied as a function of their valence during foveal and parafoveal processing. These findings suggest a processing advantage for emotional words relative to emotionally neutral stimuli in foveal and parafoveal vision. We discuss implications for the notion of attention attraction due to emotional content. |
Ying Yan; Huazhi Yuan; Xiaofei Wang; Ting Xu; Haoxue Liu Study on driver's fixation variation at entrance and inside sections of tunnel on highway Journal Article In: Advances in Mechanical Engineering, vol. 7, no. 1, pp. 1–10, 2015. @article{Yan2015d, How drivers' visual characteristics change as they pass tunnels was studied. Firstly, nine drivers' test data at tunnel entrance and inside sections using eye movement tracking devices were recorded. Then the transfer function of BP artificial neural network was employed to simulate and analyze the variation of the drivers' eye movement parameters. The relation models between eye movement parameters and the distance of the tunnels were established. In the analysis of the fixation point distributions, the analytic coordinates of fixations in visual field were clustered to obtain different visual area of fixations by utilizing dynamic cluster theory. The results indicated that, at 100 meters before the entrance, the average fixation duration increased, but the fixations number decreased substantially. After 100 meters into the tunnel, the fixation duration started to decrease first and then increased. The variations of drivers' fixation points demonstrated such a pattern of change as scatter, focus, and scatter again. While driving through the tunnels, drivers presented a long time fixation. Nearly 61.5% subjects' average fixation duration increased significantly. In the tunnel, these drivers pay attention to seven fixation points areas from the car dashboard area to the road area in front of the car. |
Lingling Yang; Howard Leung; Markus Plank; Joe Snider; Howard Poizner EEG activity during movement planning encodes upcoming peak speed and acceleration and improves the accuracy in predicting hand kinematics Journal Article In: IEEE Journal of Biomedical and Health Informatics, vol. 19, no. 1, pp. 22–28, 2015. @article{Yang2015, The relationship between movement kinematics and human brain activity is an important and fundamental question for the development of neural prosthesis. The peak velocity and the peak acceleration could best reflect the feedforward-type movement thus it is worthwhile to investigate them further. Most related studies focused on the correlation between kinematics and brain activity during the movement execution or imagery. However, human movement is the result of the motor planning phase as well as the execution phase and researchers have demonstrated that statistical correlations exist between EEG activity during the motor planning and the peak velocity and the peak acceleration using grand-average analysis. In this paper, we examined whether the correlations were concealed in trial-to-trial decoding from the low signal-to-noise ratio of EEG activity. The alpha and beta powers from the movement planning phase were combined with the alpha and beta powers from the movement execution phase to predict the peak tangential speed and acceleration. The results showed that EEG activity from the motor planning phase could also predict the peak speed and the peak acceleration with a reasonable accuracy. Furthermore, the decoding accuracy of the peak speed and the peak acceleration could both be improved by combining band powers from the motor planning phase with the band powers from the movement execution. |
Shu-Fei Yang An eye-tracking study of the Elaboration Likelihood Model in online shopping Journal Article In: Electronic Commerce Research and Applications, vol. 14, no. 4, pp. 233–240, 2015. @article{Yang2015a, This study uses eye-tracking to explore the Elaboration Likelihood Model (ELM) in online shopping. The results show that the peripheral cue did not have moderating effect on purchase intention, but had moderating effect on eye movement. Regarding purchase intention, the high elaboration had higher purchase intention than the low elaboration with a positive peripheral cue, but there was no difference in purchase intention between the high and low elaboration with a negative peripheral cue. Regarding eye movement, with a positive peripheral cue, the high elaboration group was observed to have longer fixation duration than the low elaboration group in two areas of interest (AOIs); however, with a negative peripheral cue, the low elaboration group had longer fixation on the whole page and two AOIs. In addition, the relationship between purchase intention and eye movement of the AOIs is more significant in the high elaboration group when given a negative peripheral cue and in the low elaboration group when given a positive peripheral cue. This study not only examines the postulates of the ELM, but also contributes to a better understanding of the cognitive processes of the ELM. These findings have practical implications for e-sellers to identify characteristics of consumers' elaboration in eye movement and designing customization and persuasive context for different elaboration groups in e-commerce. |
Ting Yang; Hong Chen; Yuanyan Hu; Yingcan Zheng; Wei Wang Preferences for sexual dimorphism on attractiveness levels: An eye-tracking study Journal Article In: Personality and Individual Differences, vol. 77, pp. 179–185, 2015. @article{Yang2015b, Previous studies on sexual dimorphism showed feminine preferences in female faces and mixed findings in male faces by choosing which is more attractive in a pair of a masculine face and a feminine face. However, very little is known about how people make fine-grained visual assessments of such images and the attractiveness levels of faces are not received much attention. Recently a large number of androgynous stars appear in the media, which triggers a hot phenomenon of imitating them. Here we examine the influence of androgynous stars on people's facial preferences for sexual dimorphism in male and female faces on different attractiveness levels using eye-tracking techniques. In male faces we found both male and female participants preferred masculine faces to androgynous faces in high attractiveness, but mixed results in low attractiveness. In female faces we found both male and female participants preferred feminine faces to androgynous faces in high attractiveness, but no preferences in low attractiveness. Results suggest that attractiveness levels of faces might be a factor causing inconsistency in sexual dimorphism preference for male faces and that androgynous faces are not preferred, which reveals that androgynous phenomenon might not be caused by facial attractiveness. |
Amit Yashar; Jiageng Chen; Marisa Carrasco Rapid and long-lasting reduction of crowding through training Journal Article In: Journal of Vision, vol. 15, no. 10, pp. 1–15, 2015. @article{Yashar2015, Crowding is the failure to identify an object in the peripheral visual field in the presence of nearby objects. Recent studies have shown that crowding can be alleviated after several days of training, but the processes underlying this improvement are still unclear. Here we tested whether a few hundred trials within a short period of training can alleviate crowding, whether the learning is location specific, and whether the improvement reflects facilitation by target enhancement or flankers suppression. Observers were asked to identify the orientation of a letter in the periphery surrounded by two flanker letters. Observers were tested before (pretest) and after (posttest) training (600 trials). In Experiment 1 we tested whether learning is location specific or can transfer to a different location; the training and test occurred at the same or different hemifields. In a control experiment, we ruled out alternative explanations for the learning effect in Experiment 1. In Experiment 2, we assessed different components of feature selection by training with either the same flanker polarity as the pre/posttest but opposite polarity group (flanker polarity group) or the same target polarity as the pre/posttest but opposite flanker polarity (target polarity group). Following training, overall performance increased in all four conditions, but only the same-location group (Experiment 1) and the same flanker polarity (Experiment 2) showed a significant reduction in crowding as assessed by the distance at which the flankers no longer interfere with target identification, that is, the critical spacing. These results show that training can rapidly reduce crowding and that improvement primarily reflects learning to ignore the irrelevant flankers. Remarkably, in the two conditions in which training significantly reduced crowding, the benefit of short training persisted for up to a year. |
Menahem Yeari; Paul W. Broek; Marja Oudega Processing and memory of central versus peripheral information as a function of reading goals: evidence from eye-movements Journal Article In: Reading and Writing, vol. 28, no. 8, pp. 1071–1097, 2015. @article{Yeari2015, The present study examined the effect of reading goals on the processing and memory of central and peripheral textual information. Using eye-tracking methodology, we compared the effect of four common reading goals—entertainment, presentation, studying for a close-ended (multiple-choice) questions test, and studying for an open-ended questions test—on the specific reading time of central and peripheral information and the overall reading time of expository texts. Text memory was tested using multiple-choice questions. Results showed that readers devoted more time to central information than peripheral information during initial reading, regardless of reading goal, but that they adjusted their rereading to the reading goal, with total reading time being longer for central information under some (entertainment and presentation) but not all (open-ended and close-ended questions tests) reading goals. Moreover, readers devoted more time to reading the texts for a study purpose (test or presentation) than for an entertainment purpose, and devoted more time in reading the texts to answer open-ended questions than close-ended questions. Finally, we found that readers remembered more central information than peripheral information under all reading goals. These findings suggest that centrality affects readers' early processing of text whereas reading goals only affect subsequent processing. Interestingly, processing time during reading predicted memory for peripheral information but not for central information. |
Dov Yellin; Aviva Berkovich-Ohana; Rafael Malach Coupling between pupil fluctuations and resting-state fMRI uncovers a slow build-up of antagonistic responses in the human cortex Journal Article In: NeuroImage, vol. 106, pp. 414–427, 2015. @article{Yellin2015, Even in absence of overt tasks, the human cortex manifests rich patterns of spontaneous "resting state" BOLD-fMRI fluctuations. However, the link of these spontaneous fluctuations to behavior is presently unclear. Attempts to directly investigate this link invariably lead to disruptions of the resting state. Here we took advantage of the well-established association between pupil diameter and attentional gain to address this issue by examining the correlation between the resting state BOLD and pupil fluctuations. Our results uncover a spontaneously emerging spatiotemporal pupil-BOLD correlation whereby a slow buildup of activity in default mode areas preceded both pupil dilation and wide-spread BOLD suppression in sensorimotor cortex. Control experiments excluded a role for luminance fluctuations or fixation. Comparing the pupil-correlated patterns to activation maps during visual imagery revealed a substantial overlap. Our results indicate a link between behavior, as indexed by pupil diameter, and resting state BOLD fluctuations. These pupil dilations, assumed to be related to attentional gain, were associated with spontaneously emerging antagonism between fundamental cortical networks. |
Yaffa Yeshurun; Einat Rashal; Shira Tkacz-Domb Temporal crowding and its interplay with spatial crowding Journal Article In: Journal of Vision, vol. 15, no. 3, pp. 11, 1–16, 2015. @article{Yeshurun2015, Spatial crowding refers to impaired target identification when the target is surrounded by other stimuli in space temporal crowding refers to impaired target identification when the target is surrounded by other stimuli in time previously, when spatial and temporal crowding were measured in the fovea they were interrelated with amblyopic observers but almost absent with normal observers bonneh, sagi, & polat, 2007. In the current study we examined whether reliable temporal crowding can be found for normal observers with peripheral presentation 9° of eccentricity, and whether similar relations between temporal and spatial crowding will emerge to that end, we presented a sequence of three displays separated by a varying interstimulus interval (ISI). Each display included either one letter : experiments 1a ,: 1b ,: 1c or three letters separated by a varying interletter spacing: Experiments 2a ,: 2b). One of these displays included an oriented T. Observers indicated the T's orientation. As expected, we found spatial crowding: accuracy improved as the interletter spacing increased. Critically, we also found temporal crowding: in all experiments accuracy increased as the ISI increased, even when only stimulus-onset asynchronies (SOAs) larger than 150 ms were included, ensuring this effect does not reflect mere ordinary masking. Thus, with peripheral presentation, temporal crowding also emerged for normal observers. However, only a weak interaction between temporal and spatial crowding was found. |
2014 |
Douglas A. Ruff; Marlene R. Cohen Attention can either increase or decrease spike count correlations in visual cortex Journal Article In: Nature Neuroscience, vol. 17, no. 11, pp. 1591–1597, 2014. @article{Ruff2014, Visual attention enhances the responses of visual neurons that encode the attended location. Several recent studies have shown that attention also decreases correlations between fluctuations in the responses of pairs of neurons (termed spike count correlation or r(SC)). These results are consistent with two hypotheses. First, attention-related changes in rate and r(SC) might be linked (perhaps through a common mechanism), with attention always decreasing r(SC). Second, attention might either increase or decrease r(SC), possibly depending on the role of the neurons in the behavioral task. We recorded simultaneously from dozens of neurons in area V4 while monkeys performed a discrimination task. We found strong evidence in favor of the second hypothesis, showing that attention can flexibly increase or decrease correlations depending on whether the neurons provide evidence for the same or opposite choices. These results place important constraints on models of the neuronal mechanisms underlying cognitive factors. |
Shery Thomas; Mervyn G. Thomas; Caroline Andrews; Wai-Man Chan; Frank A. Proudlock; Rebecca J. McLean; Archana Pradeep; Elizabeth C. Engle; Irene Gottlob Autosomal-dominant nystagmus, foveal hypoplasia and presenile cataract associated with a novel PAX6 mutation Journal Article In: European Journal of Human Genetics, vol. 22, no. 3, pp. 344–349, 2014. @article{Thomas2014a, Autosomal-dominant idiopathic infantile nystagmus has been linked to 6p12 (OMIM 164100), 7p11.2 (OMIM 608345) and 13q31-q33 (OMIM 193003). PAX6 (11p13, OMIM 607108) mutations can also cause autosomal-dominant nystagmus, typically in association with aniridia or iris hypoplasia. We studied a large multigenerational white British family with autosomal-dominant nystagmus, normal irides and presenile cataracts. An SNP-based genome-wide analysis revealed a linkage to a 13.4-MB region on chromosome 11p13 with a maximum lod score of 2.93. A mutation analysis of the entire coding region and splice junctions of the PAX6 gene revealed a novel heterozygous missense mutation (c.227C>G) that segregated with the phenotype and is predicted to result in the amino-acid substitution of proline by arginine at codon 76 p.(P76R). The amino-acid variation p.(P76R) within the paired box domain is likely to destabilise the protein due to steric hindrance as a result of the introduction of a polar and larger amino acid. Eye movement recordings showed a significant intrafamilial variability of horizontal, vertical and torsional nystagmus. High-resolution in vivo imaging of the retina using optical coherence tomography (OCT) revealed features of foveal hypoplasia, including rudimentary foveal pit, incursion of inner retinal layers, short photoreceptor outer segments and optic nerve hypoplasia. Thus, this study presents a family that segregates a PAX6 mutation with nystagmus and foveal hypoplasia in the absence of iris abnormalities. Moreover, it is the first study showing detailed characteristics using eye movement recordings of autosomal-dominant nystagmus in a multigenerational family with a novel PAX6 mutation. |
Rasmus Aamand; Yi-Ching Lynn Ho; Thomas Dalsgaard; Andreas Roepstorff; Torben E. Lund Dietary nitrate facilitates an acetazolamide-induced increase in cerebral blood flow during visual stimulation Journal Article In: Journal of Applied Physiology, vol. 116, no. 3, pp. 267–273, 2014. @article{Aamand2014, The carbonic anhydrase (CA) inhibitor acetazolamide (AZ) is used routinely to estimate cerebrovascular reserve capacity in patients, as it reliably increases cerebral blood flow (CBF). However, the mechanism by which AZ accomplishes this CBF increase is not entirely understood. We recently discovered that CA can produce nitric oxide (NO) from nitrite, and that AZ enhances this NO production in vitro. In fact, this interaction between AZ and CA accounted for a large part of AZ's vasodilatory action, which fits well with the known vasodilatory potency of NO. The present study aimed to assess whether AZ acts similarly in vivo in the human cerebrovascular system. Hence, we increased or minimized the dietary intake of nitrate in 20 healthy male participants, showed them a full-field flickering dartboard, and measured their CBF response to this visual stimulus with arterial spin labeling. Doing so, we found a significant positive interaction between the dietary intake of nitrate and the CBF modulation afforded by AZ during visual stimulation. In addition, but contrary to studies conducted in elderly participants, we report no effect of nitrate intake on resting CBF in healthy human participants. The present study provides in vivo support for an enhancing effect of AZ on the NO production from nitrite catalyzed by CA in the cerebrovascular system. Furthermore, our results, in combination with the results of other groups, indicate that nitrate may have significant importance to vascular function when the cerebrovascular system is challenged by age or disease. |
Naotoshi Abekawa; Toshio Inui; Hiroaki Gomi Eye-hand coordination in on-line visuomotor adjustments Journal Article In: NeuroReport, vol. 25, no. 7, pp. 441–445, 2014. @article{Abekawa2014, When we perform a visually guided reaching action, the brain coordinates our hand and eye movements. Eye-hand coordination has been examined widely, but it remains unclear whether the hand and eye motor systems are coordinated during on-line visuomotor adjustments induced by a target jump during a reaching movement. As such quick motor responses are required when we interact with dynamic environments, eye and hand movements could be coordinated even during on-line motor control. Here, we examine the relationship between online hand adjustment and saccadic eye movement. In contrast to the well-known temporal order of eye and hand initiations where the hand follows the eyes, we found that on-line hand adjustment was initiated before the saccade onset. Despite this order reversal, a correlation between hand and saccade latencies was observed, suggesting that the hand motor system is not independent of eye control even when the hand response was induced before the saccade. Moreover, the latency of the hand adjustment with saccadic eye movement was significantly shorter than that with eye fixation. This hand latency modulation cannot be ascribed to any changes of visual or oculomotor reafferent information as the saccade was not yet initiated when the hand adjustment started. Taken together, the hand motor system would receive preparation signals rather than reafference signals of saccadic eye movements to provide quick manual adjustments of the goal-directed eye-hand movements. |
Irene Ablinger; Walter Huber; Ralph Radach Eye movement analyses indicate the underlying reading strategy in the recovery of lexical readers Journal Article In: Aphasiology, vol. 28, no. 6, pp. 640–657, 2014. @article{Ablinger2014, Background: Psycholinguistic error analysis of dyslexic responses in various reading tasks provides the primary basis for clinically discriminating subtypes of pathological reading. Within this framework, phonology-related errors are indicative of a sequential word processing strategy, whereas lexical and semantic errors are associated with a lexical reading strategy. Despite the large number of published intervention studies, relatively little is known about changes in error distributions during recovery in dyslexic patients.Aims: The main purpose of the present work was to extend the scope of research on the time course of recovery in readers with acquired dyslexia, using eye tracking methodology to examine word processing in real time. The guiding hypothesis was that in lexical readers a reduction of lexical errors and an emerging predominant production of phonological errors should be associated with a change to a more segmental moment-to-moment reading behaviour.Methods & Procedures: Five patients participated in an eye movement supported reading intervention, where both lexical and segmental reading was facilitated. Reading performance was assessed before (T1) and after (T2) therapy intervention via recording of eye movements. Analyses included a novel way to examine the spatiotemporal dynamics of processing using distributions of fixation positions as different time intervals. These subdistributions reveal the gradual shifting of fixation positions during word processing, providing an adequate metric for objective classification of online reading strategies.Outcome & Results: Therapy intervention led to improved reading accuracy in all subjects. In three of five participants, analyses revealed a restructuring in the underlying reading mechanisms from predominantly lexical to more segmental word processing. In contrast, two subjects maintained their lexical reading procedures. Importantly, the fundamental assumption that a high number of phonologically based reading errors must be associated with segmental word processing routines, while the production of lexical errors is indicative of a holistic reading strategy could not be verified.Conclusions: Our results indicate that despite general improvements in reading performance, only some patients reorganised their word identification process. Contradictive data raise doubts on the validity of psycholinguistic error analysis as an exclusive indicator of changes in reading strategy. We suggest this traditional approach to combine with innovative eye tracking methodology in the interest of more comprehensive diagnostic strategies. |
Irene Ablinger; Kerstin Heyden; Christian Vorstius; Katja Halm; Walter Huber; Ralph Radach An eye movement based reading intervention in lexical and segmental readers with acquired dyslexia Journal Article In: Neuropsychological Rehabilitation, vol. 24, no. 6, pp. 833–867, 2014. @article{Ablinger2014a, Due to their brain damage, aphasic patients with acquired dyslexia often rely to a greater extent on lexical or segmental reading procedures. Thus, therapy intervention is mostly targeted on the more impaired reading strategy. In the present work we introduce a novel therapy approach based on real-time measurement of patients' eye movements as they attempt to read words. More specifically, an eye movement contingent technique of stepwise letter de-masking was used to support sequential reading, whereas fixation-dependent initial masking of non-central letters stimulated a lexical (parallel) reading strategy. Four lexical and four segmental readers with acquired central dyslexia received our intensive reading intervention. All participants showed remarkable improvements as evident in reduced total reading time, a reduced number of fixations per word and improved reading accuracy. Both types of intervention led to item-specific training effects in all subjects. A generalisation to untrained items was only found in segmental readers after the lexical training. Eye movement analyses were also used to compare word processing before and after therapy, indicating that all patients, with one exclusion, maintained their preferred reading strategy. However, in several cases the balance between sequential and lexical processing became less extreme, indicating a more effective individual interplay of both word processing routes. |
Alper Açık; Andreas Bartel; Peter König Real and implied motion at the center of gaze Journal Article In: Journal of Vision, vol. 14, no. 1, pp. 1–19, 2014. @article{Acik2014, Even though the dynamicity of our environment is a given, much of what we know on fixation selection comes from studies of static scene viewing. We performed a direct comparison of fixation selection on static and dynamic visual stimuli and investigated how far identical mechanisms drive these. We recorded eye movements while participants viewed movie clips of natural scenery and static frames taken from the same movies. Both were presented in the same high spatial resolution (1080 · 1920 pixels). The static condition allowed us to check whether local movement features computed from movies are salient even when presented as single frames. We observed that during the first second of viewing, movement and static features are equally salient in both conditions. Furthermore, predictability of fixations based on movement features decreased faster when viewing static frames as compared with viewing movie clips. Yet even during the later portion of static-frame viewing, the predictive value of movement features was still high above chance. Moreover, we demonstrated that, whereas the sets of movement and static features were statistically dependent within these sets, respectively, no dependence was observed between the two sets. Based on these results, we argue that implied motion is predictive of fixation similarly to real movement and that the onset of motion in natural stimuli is more salient than ongoing movement is. The present results allow us to address to what extent and when static image viewing is similar to the perception of a dynamic environment. |
John F. Ackermann; M. S. Landy Statistical templates for visual search Journal Article In: Journal of Vision, vol. 14, no. 3, pp. 1–17, 2014. @article{Ackermann2014, How do we find a target embedded in a scene? Within the framework of signal detection theory, this task is carried out by comparing each region of the scene with a "template," i.e., an internal representation of the search target. Here we ask what form this representation takes when the search target is a complex image with uncertain orientation. We examine three possible representations. The first is the matched filter. Such a representation cannot account for the ease with which humans can find a complex search target that is rotated relative to the template. A second representation attempts to deal with this by estimating the relative orientation of target and match and rotating the intensity-based template. No intensity-based template, however, can account for the ability to easily locate targets that are defined categorically and not in terms of a specific arrangement of pixels. Thus, we define a third template that represents the target in terms of image statistics rather than pixel intensities. Subjects performed a two-alternative, forced-choice search task in which they had to localize an image that matched a previously viewed target. Target images were texture patches. In one condition, match images were the same image as the target and distractors were a different image of the same textured material. In the second condition, the match image was of the same texture as the target (but different pixels) and the distractor was an image of a different texture. Match and distractor stimuli were randomly rotated relative to the target. We compared human performance to pixel-based, pixel-based with rotation, and statistic-based search models. The statistic-based search model was most successful at matching human performance. We conclude that humans use summary statistics to search for complex visual targets. |
Hamed Zivari Adab; Ivo D. Popivanov; Wim Vanduffel; Rufin Vogels Perceptual learning of simple stimuli modifies stimulus representations in posterior inferior temporal cortex Journal Article In: Journal of Cognitive Neuroscience, vol. 26, no. 10, pp. 2187–2200, 2014. @article{Adab2014, Practicing simple visual detection and discrimination tasks improves performance, a signature of adult brain plasticity. The neural mechanisms that underlie these changes in performance are still unclear. Previously, we reported that practice in discriminating the orientation of noisy gratings (coarse orientation discrimination) increased the ability of single neurons in the early visual area V4 to discriminate the trained stimuli. Here, we ask whether practice in this task also changes the stimulus tuning properties of later visual cortical areas, despite the use of simple grating stimuli. To identify candidate areas, we used fMRI to map activations to noisy gratings in trained rhesus monkeys, revealing a region in the posterior inferior temporal (PIT) cortex. Subsequent single unit record- ings in PIT showed that the degree of orientation selectivity was similar to that of area V4 and that the PIT neurons discriminated the trained orientations better than the untrained orientations. Unlike in previous single unit studies of perceptual learning in early visual cortex, more PIT neurons preferred trained compared with untrained orientations. The effects of training on the responses to the grating stimuli were also present when the animals were performing a difficult orthogo- nal task in which the grating stimuli were task-irrelevant, suggesting that the training effect does not need attention to be expressed. The PIT neurons could support orientation discrimination at low signal-to-noise levels. These findings suggest that extensive practice in discriminating simple grating stimuli not only affects early visual cortex but also changes the stimulus tuning of a late visual cortical area. |
Jos J. Adam; Thamar J. H. Bovend'Eerdt; Fren T. Y. Smulders; Pascal W. M. Van Gerven Strategic flexibility in response preparation: Effects of cue validity on reaction time and pupil dilation Journal Article In: Journal of Cognitive Psychology, vol. 26, no. 2, pp. 166–177, 2014. @article{Adam2014, This study examined the ability of participants to strategically adapt their level of response preparation to the predictive value of preparatory cues. Participants performed the finger-precuing task under three levels of cue validity: 100, 75 and 50% valid. Response preparation was indexed by means of reaction time (RT) and pupil dilation, the latter providing a psychophysiological index of invested effort. Results showed a systematic increase in RT benefits (generated by valid cues) and RT costs (generated by invalid cues) with increments in the predictive value of cues. Converging with these behavioural effects, pupil dilation also increased systematically with greater cue validity during the cue-stimulus interval, suggesting more effortful response preparation with increases in cue validity. Together, these findings confirm the hypothesis that response preparation is flexible and that it can be strategically allocated in proportion to the relative frequency of valid/invalid preparatory cues. |
Elsa Ahlén; Charlotte S. Hills; Hashim M. Hanif; Cristina Rubino; Jason J. S. Barton Learning to read upside-down: A study of perceptual expertise and its acquisition Journal Article In: Experimental Brain Research, vol. 232, no. 3, pp. 1025–1036, 2014. @article{Ahlen2014, Reading is an expert visual and ocular motor function, learned mainly in a single orientation. Characterizing the features of this expertise can be accomplished by contrasts between reading of normal and inverted text, in which perceptual but not linguistic factors are altered. Our goal was to examine this inversion effect in healthy subjects reading text, to derive behavioral and ocular motor markers of perceptual expertise in reading, and to study these parameters before and after training with inverted reading. Seven subjects engaged in a 10-week program of 30 half-hour sessions of reading inverted text. Before and after training, we assessed reading of upright and inverted single words for response time and word-length effects, as well as reading of paragraphs for time required, accuracy, and ocular motor parameters. Before training, inverted reading was characterized by long reading times and large word-length effects, with eye movements showing more and longer fixations, more and smaller forward saccades, and more regressive saccades. Training partially reversed many of these effects in single word and text reading, with the best gains occurring in reading aloud time and proportion of regressive saccades and the least change in forward saccade amplitude. We conclude that reading speed and ocular motor parameters can serve as markers of perceptual expertise during reading and that training with inverted text over 10 weeks results in significant gains of reading expertise in this unfamiliar orientation. This approach may be useful in the rehabilitation of patients with hemianopic dyslexia. |
Sheeraz Ahmad; He Huang; Angela J. Yu Cost-sensitive Bayesian control policy in human active sensing Journal Article In: Frontiers in Human Neuroscience, vol. 8, pp. 955, 2014. @article{Ahmad2014, An important but poorly understood aspect of sensory processing is the role of active sensing, the use of self-motion such as eye or head movements to focus sensing resources on the most rewarding or informative aspects of the sensory environment. Here, we present behavioral data from a visual search experiment, as well as a Bayesian model of within-trial dynamics of sensory processing and eye movements. Within this Bayes-optimal inference and control framework, which we call C-DAC (Context-Dependent Active Controller), various types of behavioral costs, such as temporal delay, response error, and sensor repositioning cost, are explicitly minimized. This contrasts with previously proposed algorithms that optimize abstract statistical objectives such as anticipated information gain (Infomax) (Butko and Movellan, 2010) and expected posterior maximum (greedy MAP) (Najemnik and Geisler, 2005). We find that C-DAC captures human visual search dynamics better than previous models, in particular a certain form of "confirmation bias" apparent in the way human subjects utilize prior knowledge about the spatial distribution of the search target to improve search speed and accuracy. We also examine several computationally efficient approximations to C-DAC that may present biologically more plausible accounts of the neural computations underlying active sensing, as well as practical tools for solving active sensing problems in engineering applications. To summarize, this paper makes the following key contributions: human visual search behavioral data, a context-sensitive Bayesian active sensing model, a comparative study between different models of human active sensing, and a family of efficient approximations to the optimal model. |
Noor Z. Al Dahhan; George K. Georgiou; Rickie Hung; Douglas P. Munoz; Rauno Parrila; John R. Kirby Eye movements of university students with and without reading difficulties during naming speed tasks Journal Article In: Annals of Dyslexia, vol. 64, no. 2, pp. 137–150, 2014. @article{AlDahhan2014, Although naming speed (NS) has been shown to predict reading into adulthood and differentiate between adult dyslexics and controls, the question remains why NS is related to reading. To address this question, eye movement methodology was combined with three letter NS tasks (the original letter NS task by Denckla & Rudel, Cortex 10:186-202, 1974, and two more developed by Compton, The Journal of Special Education 37:81-94, 2003, with increased phonological or visual similarity of the letters). Twenty undergraduate students with reading difficulties (RD) and 27 without (NRD) were tested on letter NS tasks (eye movements were recorded during the NS tasks), phonological processing, and reading fluency. The results indicated first that the RD group was slower than the NRD group on all NS tasks with no differences between the NS tasks. In addition, the NRD group had shorter fixation durations, longer saccades, and fewer saccades and fixations than the RD group. Fixation duration and fixation count were significant predictors of reading fluency even after controlling for phonological processing measures. Taken together, these findings suggest that the NS-reading relationship is due to two factors: less able readers require more time to acquire stimulus information during fixation and they make more saccades. |
Robert G. Alexander; Joseph Schmidt; Gregory J. Zelinsky Are summary statistics enough? Evidence for the importance of shape in guiding visual search Journal Article In: Visual Cognition, vol. 22, no. 3, pp. 595–609, 2014. @article{Alexander2014, Peripheral vision outside the focus of attention may rely on summary statistics. We used a gaze-contingent paradigm to directly test this assumption by asking whether search performance differed between targets and statistically-matched visualizations of the same targets. Four-object search displays included one statistically-matched object that was replaced by an unaltered version of the object during the first eye movement. Targets were designated by previews, which were never altered. Two types of statistically-matched objects were tested: One that maintained global shape and one that did not. Differences in guidance were found between targets and statistically-matched objects when shape was not preserved, suggesting that they were not informationally equivalent. Responses were also slower after target fixation when shape was not preserved, suggesting an extrafoveal processing of the target that again used shape information. We conclude that summary statistics must include some global shape information to approximate the peripheral information used during search. |
Eric S. Allard; Elizabeth A. Kensinger Age-related differences in neural recruitment during the use of cognitive reappraisal and selective attention as emotion regulation strategies Journal Article In: Frontiers in Psychology, vol. 5, pp. 296, 2014. @article{Allard2014, The present study examined age differences in the timing and neural recruitment within lateral and medial PFC while younger and older adults hedonically regulated their responses to unpleasant film clips. When analyses focused on activity during the emotional peak of the film clip (the most emotionally salient portion of the film), several age differences emerged. When comparing regulation to passive viewing (combined effects of selective attention and reappraisal) younger adults showed greater regulation related activity in lateral PFC (DLPFC, VLPFC, OFC) and medial PFC (ACC) while older adults showed greater activation within a region DLPFC. When assessing distinct effects of the regulation conditions, an ANOVA revealed a significant Age x Regulation Condition interaction within bilateral DLPFC and ACC; older adults but not young adults showed greater recruitment within these regions for reappraisal than selective attention. When examining activity at the onset of the film clip and at its emotional peak, the timing of reappraisal-related activity within VLPFC differed between age groups: younger adults showed greater activity at film onset while older adults showed heightened activity during the peak. Our results suggest that older adults rely more heavily on PFC recruitment when engaging cognitively demanding reappraisal strategies while PFC-mediated regulation might not be as task-specific for younger adults. Older adults' greater reliance on cognitive control processing during emotion regulation may also be reflected in the time needed to implement these strategies. |
Eric S. Allard; Elizabeth A. Kensinger Age-related differences in functional connectivity during cognitive emotion regulation Journal Article In: Journals of Gerontology - Series B Psychological Sciences and Social Sciences, vol. 69, no. 6, pp. 852–860, 2014. @article{Allard2014a, OBJECTIVES: Successful emotion regulation partly depends on our capacity to modulate emotional responses through the use of cognitive strategies. Age may affect the strategies employed most often; thus, we examined younger and older adults' neural network connectivity when employing two different strategies: cognitive reappraisal and selective attention.$backslash$n$backslash$nMETHOD: The current study used psychophysiological interaction analyses to examine functional connectivity with a region of anterior cingulate cortex (ACC) because it is a core part of an emotion regulation network showing relative structural preservation with age.$backslash$n$backslash$nRESULTS: Functional connectivity between ACC and prefrontal cortex (PFC) was greater for reappraisal relative to selective attention and passive viewing conditions for both age groups. For younger adults, ACC was more strongly connected with lateral dorsolateral PFC, ventrolateral PFC, dorsomedial PFC, and posterior cingulate regions during reappraisal. For older adults, stronger connectivity during reappraisal was observed primarily in ventromedial PFC and orbitofrontal cortex.$backslash$n$backslash$nDISCUSSION: Our results suggest that although young and older adults engage PFC networks during regulation, and particularly during reappraisal, the regions within these networks might differ. Additionally, these results clarify that, despite prior evidence for age-related declines in the structure and function of those regions, older adults are able to recruit ACC and PFC regions as part of coherent network during emotion regulation. |
Ted S. Altschuler; Sophie Molholm; John S. Butler; Manuel R. Mercier; Alice B. Brandwein; John J. Foxe In: NeuroImage, vol. 90, pp. 360–373, 2014. @article{Altschuler2014, The adult human visual system can efficiently fill-in missing object boundaries when low-level information from the retina is incomplete, but little is known about how these processes develop across childhood. A decade of visual-evoked potential (VEP) studies has produced a theoretical model identifying distinct phases of contour completion in adults. The first, termed a perceptual phase, occurs from approximately 100-200. ms and is associated with automatic boundary completion. The second is termed a conceptual phase occurring between 230 and 400. ms. The latter has been associated with the analysis of ambiguous objects which seem to require more effort to complete. The electrophysiological markers of these phases have both been localized to the lateral occipital complex, a cluster of ventral visual stream brain regions associated with object-processing. We presented Kanizsa-type illusory contour stimuli, often used for exploring contour completion processes, to neurotypical persons ages 6-31 (N. = 63), while parametrically varying the spatial extent of these induced contours, in order to better understand how filling-in processes develop across childhood and adolescence. Our results suggest that, while adults complete contour boundaries in a single discrete period during the automatic perceptual phase, children display an immature response pattern-engaging in more protracted processing across both timeframes and appearing to recruit more widely distributed regions which resemble those evoked during adult processing of higher-order ambiguous figures. However, children older than 5. years of age were remarkably like adults in that the effects of contour processing were invariant to manipulation of contour extent. |
Ilhame Ameqrane; Pierre Pouget; Nicolas Wattiez; Roger Carpenter; Marcus Missal Implicit and explicit timing in oculomotor control Journal Article In: PLoS ONE, vol. 9, no. 4, pp. e93958, 2014. @article{Ameqrane2014, The passage of time can be estimated either explicitly, e.g. before leaving home in the morning, or implicitly, e.g. when catching a flying ball. In the present study, the latency of saccadic eye movements was used to evaluate differences between implicit and explicit timing. Humans were required to make a saccade between a central and a peripheral position on a computer screen. The delay between the extinction of a central target and the appearance of an eccentric target was the independent variable that could take one out of four different values (400, 900, 1400 or 1900 ms). In target trials, the delay period lasted for one of the four durations randomly. At the end of the delay, a saccade was initiated by the appearance of an eccentric target. Cue&target trials were similar to target trials but the duration of the delay was visually cued. In probe trials, the duration of the upcoming delay was cued, but there was no eccentric target and subjects had to internally generate a saccade at the estimated end of the delay. In target and cue&target trials, the mean and variance of latency distributions decreased as delay duration increased. In cue&target trials latencies were shorter. In probe trials, the variance increased with increasing delay duration and scalar variability was observed. The major differences in saccadic latency distributions were observed between visually-guided (target and cue&target trials) and internally-generated saccades (probe trials). In target and cue&target trials the timing of the response was implicit. In probe trials, the timing of the response was internally-generated and explicitly based on the duration of the visual cue. Scalar timing was observed only during probe trials. This study supports the hypothesis that there is no ubiquitous timing system in the brain but independent timing processes active depending on task demands. |
Bernhard Angele; Abby E. Laishley; Keith Rayner; Simon P. Liversedge The effect of high- and low-frequency previews and sentential fit on word skipping during reading Journal Article In: Journal of Experimental Psychology: Learning, Memory, and Cognition, vol. 40, no. 4, pp. 1181–1203, 2014. @article{Angele2014, In a previous gaze-contingent boundary experiment, Angele and Rayner (2013) found that readers are likely to skip a word that appears to be the definite article the even when syntactic constraints do not allow for articles to occur in that position. In the present study, we investigated whether the word frequency of the preview of a 3-letter target word influences a reader's decision to fixate or skip that word. We found that the word frequency rather than the felicitousness (syntactic fit) of the preview affected how often the upcoming word was skipped. These results indicate that visual information about the upcoming word trumps information from the sentence context when it comes to making a skipping decision. Skipping parafoveal instances of the therefore may simply be an extreme case of skipping high-frequency words. |
Mari Anzai; Soich Nagao Motor learning in common marmosets: Vestibulo-ocular reflex adaptation and its sensitivity to inhibitors of Purkinje cell long-term depression Journal Article In: Neuroscience Research, vol. 83, pp. 33–42, 2014. @article{Anzai2014, Adaptation of the horizontal vestibulo-ocular reflex (HVOR) provides an experimental model for cerebellum-dependent motor learning. We developed an eye movement measuring system and a paradigm for induction of HVOR adaptation for the common marmoset. The HVOR gain in dark measured by 10° (peak-to-peak amplitude) and 0.11-0.5. Hz turntable oscillation was around unity. The gain-up and gain-down HVOR adaptation was induced by 1. h of sustained out-of-phase and in-phase 10°-0.33. Hz combined turntable-screen oscillation in the light, respectively. To examine the role of long-term depression (LTD) of parallel fiber-Purkinje cell synapses, we intraperitonially applied T-588 or nimesulide, which block the induction of LTD in vitro or in vivo preparations, 1. h before the test of HVOR adaptation. T-588 (3 and 5. mg/kg body weight) did not affect nonadapted HVOR gains, and impaired both gain-up and gain-down HVOR adaptation. Nimesulide (3 and 6. mg/kg) did not affect nonadapted HVOR gains, and impaired gain-up HVOR adaptation dose-dependently; however, it very little affected gain-down HVOR adaptation. These findings are consistent with the results of our study of nimesulide on the adaptation of horizontal optokinetic response in mice (. Le et al., 2010), and support the view that LTD underlies HVOR adaptation. |
Manabu Arai; Reiko Mazuka The development of Japanese passive syntax as indexed by structural priming in comprehension Journal Article In: Quarterly Journal of Experimental Psychology, vol. 67, no. 1, pp. 60–78, 2014. @article{Arai2014, A number of previous studies reported a phenomenon of syntactic priming with young children as evidence for cognitive representations required for processing syntactic structures. However, it remains unclear how syntactic priming reflects children's grammatical competence. The current study investigated structural priming of the Japanese passive structure with 5- and 6-year-old children in a visual-world setting. Our results showed a priming effect as anticipatory eye movements to an upcoming referent in these children but the effect was significantly stronger in magnitude in 6-year-olds than in 5-year-olds. Consistently, the responses to comprehension questions revealed that 6-year-olds produced a greater number of correct answers and more answers using the passive structure than 5-year-olds. We also tested adult participants who showed even stronger priming than the children. The results together revealed that language users with the greater linguistic competence with the passives exhibited stronger priming, demonstrating a tight relationship between the effect of priming and the development of grammatical competence. Furthermore, we found that the magnitude of the priming effect decreased over time. We interpret these results in the light of an error-based learning account. Our results also provided evidence for prehead as well as head-independent priming. |
Anne Atas; Nathan Faivre; Bert Timmermans; Axel Cleeremans; Sid Kouider Nonconscious learning from crowded sequences Journal Article In: Psychological Science, vol. 25, no. 1, pp. 113–119, 2014. @article{Atas2014, Can people learn complex information without conscious awareness? Implicit learning-learning without awareness of what has been learned-has been the focus of intense investigation over the last 50 years. However, it remains controversial whether complex knowledge can be learned implicitly. In the research reported here, we addressed this challenge by asking participants to differentiate between sequences of symbols they could not perceive consciously. Using an operant-conditioning task, we showed that participants learned to associate distinct sequences of crowded (nondiscriminable) symbols with their respective monetary outcomes (reward or punishment). Overall, our study demonstrates that sensitivity to sequential regularities can arise through the nonconscious temporal integration of perceptual information. |
Jeroen Atsma; Femke Maij; Brian D. Corneil; W. Pieter Medendorp No perisaccadic mislocalization with abruptly cancelled saccades Journal Article In: Journal of Neuroscience, vol. 34, no. 16, pp. 5497–5504, 2014. @article{Atsma2014, Every saccadic eye movement that we make changes the image of the world on our retina. Yet, despite these retinal shifts, we still perceive our visual world to be stable. Efference copy from the oculomotor system to the visual system has been suggested to contribute to this stable percept, enabling the brain to anticipate the retinal image shifts by remapping the neural image. A psychophysical phenomenon that has been linked to this predictive remapping is the mislocalization of a stimulus flashed around the time of a saccade. If this mislocalization is initiated by saccade preparation, one should also observe localization errors when a saccade is planned, but abruptly aborted just before its execution. We tested this hypothesis in human subjects using a novel paradigm that combines a flash localization task with a countermanding component that occasionally requires saccade cancellation. Surprisingly, we found no trace of mislocalization, even for saccades cancelled close to the point of no return. This strongly suggests that the actual execution of the saccade is a prerequisite for the typical localization errors, which rejects various models and constrains neural substrates. We conclude that perisaccadic mislocalization is not a direct consequence of saccade preparation, but arises after saccade execution when the flash location is constructed from memory. |
Janice Attard; Markus Bindemann Establishing the duration of crimes: An individual differences and eye-tracking investigation into time estimation Journal Article In: Applied Cognitive Psychology, vol. 28, no. 2, pp. 215–225, 2014. @article{Attard2014, The time available for viewing a perpetrator at a crime scene predicts successful person recognition in subsequent identity line-ups. This time is usually unknown and must be derived from eyewitnesses' duration estimates. This study therefore compared the estimates that different individuals provide for crimes. We then attempted to determine the accuracy of these durations by measuring observers' general time estimation ability with a set of estimator videos. Observers differed greatly in their ability to estimate time, but individual duration estimates correlated strongly for crime and estimator materials. This indicates that it might be possible to infer unknown durations of events, such as criminal incidents, from a person's ability to estimate known durations. We also measured observers' eye movements to a perpetrator during crimes. Only fixations on a perpetrator's face related to eyewitness accuracy, but these fixations did not correlate with exposure estimates for this person. The implications of these findings are discussed. |
Stefanie I. Becker; Anthony M. Harris; Dustin Venini; James D. Retell Visual search for color and shape: When is the gaze guided by feature relationships, when by feature values? Journal Article In: Journal of Experimental Psychology: Human Perception and Performance, vol. 40, no. 1, pp. 264–291, 2014. @article{Becker2014, One of the most widespread views in vision research is that top-down control over visual selection is achieved by tuning attention to a particular feature value (e.g., red/yellow). Contrary to this view, previous spatial cueing studies showed that attention can be tuned to relative features of a search target (e.g., redder): An irrelevant distractor (cue) captured attention when it had the same relative color as the target (e.g., redder), and failed to capture when it had a different relative color, regardless of whether the distractor was similar or dissimilar to the target. The present study tested whether the same effects would be observed for eye movements when observers have to search for a color or shape target and when selection errors were very noticeable (resulting in an erroneous eye movement to the distractor). The results corroborated the previous findings, showing that capture by an irrelevant distractor does not depend on the distractor's similarity to the target but on whether it matches or mismatches the relative attributes of the search target. Extending on previous work, we also found that participants can be pretrained to select a color target in virtue of its exact feature value. Contrary to the prevalent feature-based view, the results suggest that visual selection is preferentially biased toward the relative attributes of a search target. Simultaneously, however, visual selection can be biased to specific color values when the task requires it, which rules out a purely relational account of attention and eye movements. (PsycINFO Database Record (c) 2014 APA, all rights reserved). |
Stefanie I. Becker; Christian Valuch; Ulrich Ansorge Color priming in pop-out search depends on the relative color of the target Journal Article In: Frontiers in Psychology, vol. 5, pp. 289, 2014. @article{Becker2014a, In visual search for pop-out targets, search times are shorter when the target and non-target colors from the previous trial are repeated than when they change. This priming effect was originally attributed to a feature weighting mechanism that biases attention toward the target features, and away from the non-target features. However, more recent studies have shown that visual selection is strongly context-dependent: according to a relational account of feature priming, the target color is always encoded relative to the non-target color (e.g., as redder or greener). The present study provides a critical test of this hypothesis, by varying the colors of the search items such that either the relative color or the absolute color of the target always remained constant (or both). The results clearly show that color priming depends on the relative color of a target with respect to the non-targets but not on its absolute color value. Moreover, the observed priming effects did not change over the course of the experiment, suggesting that the visual system encodes colors in a relative manner from the start of the experiment. Taken together, these results strongly support a relational account of feature priming in visual search, and are inconsistent with the dominant feature-based views. |
Y. Behnke Visual qualities of future geography books Journal Article In: European Journal of Geography, vol. 5, no. 4, pp. 56–66, 2014. @article{Behnke2014, The capacity for spatial orientation and associated faculties are closely related to visual competencies. Consequently, the practice and acquisition of visual competencies are vital prerequisites to successful learning and teaching of geography. Today, geography can be understood as a visual discipline and as such may develop strong links to visual communication. In geography, textbooks may establish this link in an everyday context. This Ph.D. project aims to build the bridge between subject content and design. The result will be a visually convincing geography textbook prototype. Fifty-six geography textbooks from different European countries were analysed, focussing on the design concept. Furthermore, double-page spreads of current German geography textbooks were evaluated by observing students' textbook usage via eye tracking. Eye tracking monitors students' reactions to varying contents and designs. Findings from both analyses form the basis for the textbook concept, which is to be developed. |
Ashley Benatar; Charles Clifton Newness, givenness and discourse updating: Evidence from eye movements Journal Article In: Journal of Memory and Language, vol. 71, no. 1, pp. 1–16, 2014. @article{Benatar2014, Three experiments examined the effect of contextual givenness on eye movements in reading, following Schwarzschild's (1999) analysis of givenness and focus-marking in which relations among entities as well as the entities themselves can be given. In each study, a context question was followed by an answer in which a critical word was either given, new, or contrastively (correctively) focused. Target words were read faster when the critical word provided given information than when it provided new information, and faster when it provided new information than when it corrected prior information. Repetition of target words was controlled in two ways: by mentioning a non-given target word in the context in a relation other than that in which it occurred as a target, and by using a synonym or subordinate of a given target to refer to it in the context question. Verbatim repetition was not responsible for the observed effects of givenness and contrastiveness. Besides clarifying previous inconsistent results of the effects of focus and givenness on reading speed, these results indicate that reading speed can be influenced essentially immediately by a reader's discourse representation, and that the extent of the influence is graded, with corrections to a representation having a larger effect than simple additions. |
Erin Berenbaum; Amy E. Latimer-Cheung Examining the link between framed physical activity ads and behavior among women Journal Article In: Journal of Sport and Exercise Psychology, vol. 36, no. 3, pp. 271–280, 2014. @article{Berenbaum2014, Gain-framed messages are more effective at promoting physical activity than loss-framed messages. However, the mechanism through which this effect occurs is unclear. The current experiment examined the effects of message framing on variables described in the communication behavior change model (McGuire, 1989), as well as the mediating effects of these variables on the message-frame-behavior relationship. Sixty low-to-moderately active women viewed 20 gain- or loss-framed ads and five control ads while their eye movements were recorded via eye tracking. The gain-framed ads attracted greater attention, ps < .05; produced more positive attitudes |
Jean-Baptiste Bernard; Aurélie Calabrèse; Eric Castet Role of syllable segmentation processes in peripheral word recognition Journal Article In: Vision Research, vol. 105, pp. 226–232, 2014. @article{Bernard2014, Previous studies of foveal visual word recognition provide evidence for a low-level syllable decomposition mechanism occurring during the recognition of a word. We investigated if such a decomposition mechanism also exists in peripheral word recognition. Single words were visually presented to subjects in the peripheral field using a 6° square gaze-contingent simulated central scotoma. In the first experiment, words were either unicolor or had their adjacent syllables segmented with two different colors (color/syllable congruent condition). Reaction times for correct word identification were measured for the two different conditions and for two different print sizes. Results show a significant decrease in reaction time for the color/syllable congruent condition compared with the unicolor condition. A second experiment suggests that this effect is specific to syllable decomposition and results from strategic, presumably involving attentional factors, rather than stimulus-driven control. |
Richard A. I. Bethlehem; Serge O. Dumoulin; Edwin S. Dalmaijer; Miranda Smit; Tos T. J. M. Berendschot; Tanja C. W. Nijboer; Stefan Van Der Stigchel Decreased fixation stability of the preferred retinal location in juvenile macular degeneration Journal Article In: PLoS ONE, vol. 9, no. 6, pp. e100171, 2014. @article{Bethlehem2014, Macular degeneration is the main cause for diminished visual acuity in the elderly. The juvenile form of macular degeneration has equally detrimental consequences on foveal vision. To compensate for loss of foveal vision most patients with macular degeneration adopt an eccentric preferred retinal location that takes over tasks normally performed by the healthy fovea. It is unclear however, whether the preferred retinal locus also develops properties typical for foveal vision. Here, we investigated whether the fixation characteristics of the preferred retinal locus resemble those of the healthy fovea. For this purpose, we used the fixation-offset paradigm and tracked eye-position using a high spatial and temporal resolution infrared eye-tracker. The fixation-offset paradigm measures release from fixation under different fixation conditions and has been shown useful to distinguish between foveal and non-foveal fixation. We measured eye-movements in nine healthy age-matched controls and five patients with juvenile macular degeneration. In addition, we performed a simulation with the same task in a group of five healthy controls. Our results show that the preferred retinal locus does not adopt a foveal type of fixation but instead drifts further away from its original fixation and has overall increased fixation instability. Furthermore, the fixation instability is most pronounced in low frequency eye-movements representing a slow drift from fixation. We argue that the increased fixation instability cannot be attributed to fixation under an unnatural angle. Instead, diminished visual acuity in the periphery causes reduced oculomotor control and results in increased fixation instability. |
Lysianne Beynel; Alan Chauvin; Nathalie Guyader; Sylvain Harquel; Thierry Bougerol; Christian Marendaz; David Szekely What saccadic eye movements tell us about TMS-induced neuromodulation of the DLPFC and mood changes: A pilot study in bipolar disorders Journal Article In: Frontiers in Integrative Neuroscience, vol. 8, pp. 65, 2014. @article{Beynel2014, The study assumed that the antisaccade (AS) task is a relevant psychophysical tool to assess (i) short-term neuromodulation of the dorsolateral prefrontal cortex (DLPFC) induced by intermittent theta burst stimulation (iTBS); and (ii) mood change occurring during the course of the treatment. Saccadic inhibition is known to strongly involve the DLPFC, whose neuromodulation with iTBS requires less stimulation time and lower stimulation intensity, as well as results in longer aftereffects than the conventional repetitive transcranial magnetic stimulation (rTMS). Active or sham iTBS was applied every day for 3 weeks over the left DLPFC of 12 drug-resistant bipolar depressed patients. To assess the iTBS-induced short-term neuromodulation, the saccadic task was performed just before (S1) and just after (S2) the iTBS session, the first day of each week. Mood was evaluated through Montgomery and Asberg Depression Rating Scale (MADRS) scores and the difference in scores between the beginning and the end of treatment was correlated with AS performance change between these two periods. As expected, only patients from the active group improved their performance from S1 to S2 and mood improvement was significantly correlated with AS performance improvement. In addition, the AS task also discriminated depressive bipolar patients from healthy control subjects. Therefore, the AS task could be a relevant and useful tool for clinicians to assess if the Transcranial magnetic stimulation (TMS)-induced short-term neuromodulation of the DLPFC occurs as well as a “trait vs. state” objective marker of depressive mood disorder. |
Daniel Bishop; Gustav Kuhn; Claire Maton Telling people where to look in a soccer-based decision task: A nomothetic approach Journal Article In: Journal of Eye Movement Research, vol. 7, no. 2, pp. 1–13, 2014. @article{Bishop2014, Research has shown that identifiable visual search patterns characterize skilled performance of anticipation and decision-making tasks in sport. However, to date, the use of experts' gaze patterns to entrain novices' performance has been confined to aiming activities. Accordingly, in a first experiment, 40 participants of varying soccer experience viewed static images of oncoming soccer players and attempted to predict the direction in which those players were about to move. Multiple regression analyses showed that the sole predictor of decision-making efficiency was the time taken to initiate a saccade to the ball. In a follow-up experiment, soccer novices undertook the same task as in Experiment 1. Two experimental groups were instructed to either look at the ball, or the player's head, as quickly as possible; a control group received no instructions. The experimental groups were fastest to make a saccade to the ball or head, respectively, but decision-making efficiency was equivalent across all three groups. The fallibility of a nomothetic approach to training eye movements is discussed. |
Marie-Josée Bisson; Walter J. B. Van Heuven; Kathy Conklin; Richard J. Tunney Processing of native and foreign language subtitles in films: An eye tracking study Journal Article In: Applied Psycholinguistics, vol. 35, no. 2, pp. 399–418, 2014. @article{Bisson2014, Foreign language (FL) films with subtitles are becoming increasingly popular, and many European countries use subtitling as a cheaper alternative to dubbing. However, the extent to which people process subtitles under different subtitling conditions remains unclear. In this study, participants watched part of a film under standard (FL soundtrack and native language subtitles), reversed (native language soundtrack and FL subtitles), or intralingual (FL soundtrack and FL subtitles) subtitling conditions while their eye movements were recorded. The results revealed that participants read the subtitles irrespective of the subtitling condition. However, participants exhibited more regular reading of the subtitles when the film soundtrack was in an unknown FL. To investigate the incidental acquisition of FL vocabulary, participants also completed an unexpected auditory vocabulary test. Because the results showed no vocabulary acquisition, the need for more sensitive measures of vocabulary acquisition are discussed. Finally, the reading of the subtitles is discussed in relation to the saliency of subtitles and automatic reading behavior. |
Laura Eklinder Björnström; Charlotte S. Hills; Hashim M. Hanif; Jason J. S. Barton Visual word expertise: A study of inversion and the word-length effect, with perceptual transforms Journal Article In: Perception, vol. 43, no. 5, pp. 438–450, 2014. @article{Bjoernstroem2014, The word-length effect may indicate whether reading is proceeding in an efficient whole-word fashion or by serial letter processing. If it is an index of an orientation-dependent expert reading mechanism, then it should show an inversion effect, with a large difference between upright and upside-down text that is specific for normally configured text. We measured response time of healthy subjects reading 3- to 9-letter words presented in normal configuration, in mirror reflection or spelt backward, in either upright or inverted orientation. The word-length effect showed an inversion effect specific for normal text, as it was not seen for either backward or mirrored text, a result that differed from that for simple mean response times. Also, the word-length effect was smaller for backward than for mirrored text, suggesting that reading of transformed text uses primarily local letters rather than global word forms. We conclude that the word-length effect is a suitable index of expert reading, and reveals that reading under perceptually difficult conditions relies on a sublexical letter-based strategy. |
T. C. Blanchard; Benjamin Y. Hayden Neurons in dorsal anterior cingulate cortex signal postdecisional variables in a foraging task Journal Article In: Journal of Neuroscience, vol. 34, no. 2, pp. 646–655, 2014. @article{Blanchard2014, The dorsal anterior cingulate cortex (dACC) is a key hub of the brain's executive control system. Although a great deal is known about its role in outcome monitoring and behavioral adjustment, whether and how it contributes to the decision process remain unclear. Some theories suggest that dACC neurons track decision variables (e.g., option values) that feed into choice processes and is thus "predecisional." Other theories suggest that dACC activity patterns differ qualitatively depending on the choice that is made and is thus "postdecisional." To compare these hypotheses, we examined responses of 124 dACC neurons in a simple foraging task in which monkeys accepted or rejected offers of delayed rewards. In this task, options that vary in benefit (reward size) and cost (delay) appear for 1 s; accepting the option provides the cued reward after the cued delay. To get at dACC neurons' contributions to decisions, we focused on responses around the time of choice, several seconds before the reward and the end of the trial. We found that dACC neurons signal the foregone value of the rejected option, a postdecisional variable. Neurons also signal the profitability (that is, the relative value) of the offer, but even these signals are qualitatively different on accept and reject decisions, meaning that they are also postdecisional. These results suggest that dACC can be placed late in the decision process and also support models that give it a regulatory role in decision, rather than serving as a site of comparison. |
Tommy C. Blanchard; Andreas Wilke; Benjamin Y. Hayden Hot-hand bias in rhesus monkeys Journal Article In: Journal of Experimental Psychology: Animal Behavior Processes, vol. 40, no. 3, pp. 280–286, 2014. @article{Blanchard2014a, Human decision-makers often exhibit the hot-hand phenomenon, a tendency to perceive positive serial autocorrelations in independent sequential events. The term is named after the observation that basketball fans and players tend to perceive streaks of high accuracy shooting when they are demonstrably absent. That is, both observing fans and participating players tend to hold the belief that a player's chance of hitting a shot are greater following a hit than following a miss. We hypothesize that this bias reflects a strong and stable tendency among primates (including humans) to perceive positive autocorrelations in temporal sequences, that this bias is an adaptation to clumpy foraging environments, and that it may even be ecologically rational. Several studies support this idea in humans, but a stronger test would be to determine whether nonhuman primates also exhibit a hot-hand bias. Here we report behavior of 3 monkeys performing a novel gambling task in which correlation between sequential gambles (i.e., temporal clumpiness) is systematically manipulated. We find that monkeys have better performance (meaning, more optimal behavior) for clumped (positively correlated) than for dispersed (negatively correlated) distributions. These results identify and quantify a new bias in monkeys' risky decisions, support accounts that specifically incorporate cognitive biases into risky choice, and support the suggestion that the hot-hand phenomenon is an evolutionary ancient bias. |
Tommy C. Blanchard; Lauren S. Wolfe; Ivo Vlaev; Joel S. Winston; Benjamin Y. Hayden Biases in preferences for sequences of outcomes in monkeys Journal Article In: Cognition, vol. 130, no. 3, pp. 289–299, 2014. @article{Blanchard2014b, Movies, vacations, and meals are all examples of events composed of a sequence of smaller events. How do we go from our evaluations of each scene in a movie to an evaluation of the sequence as a wholeα In theory, we should simply average the values of the individual events. In practice, however, we are biased towards sequences where each element tends to be better than the previous, where the last value is large, and we overweight the best (or worst) part of the sequence. To study how general these biases are we examined monkeys' preferences for sequences of rewards in a novel reward repeat task. Monkeys were first given a sequence of rewards and then chose between repeating the sequence or receiving a standard comparator sequence. We found that, like humans, monkeys overweight events that happen later in a sequence, so much so that adding a small reward to the end of a sequence can paradoxically reduce its value. Monkeys were also biased towards sequences with large peak values (the highest value in the sequence), but only following a working memory challenge, suggesting that this preference may be driven by memory limitations. These results demonstrate the cross-species nature of biases in preferences for sequences of outcomes. In addition, monkeys' consistent preference for sequences in which large values occur later challenges the generality of discounting models of intertemporal choice in animals. |
Julieanne Blum; Nicholas S. C. Price Reflexive tracking eye movements and motion perception: One or two neural populations? Journal Article In: Journal of Vision, vol. 14, no. 3, pp. 1–14, 2014. @article{Blum2014, Motion-sensitive neurons in the middle temporal (MT) and medial superior temporal (MST) areas perform the sensory analysis required for both motion perception and controlling smooth eye movements. The perceptual and oculomotor systems are characterized by high variability, even when responding to identical stimulus repetitions. If a single population of neurons performs the motion analysis driving perception and eye movements, errors in perception and action might show similar direction-dependent biases, or their variability might be correlated across trials. However, previous studies have produced conflicting reports of the presence of significant single-trial correlations between motion perception and the velocity of smooth pursuit, a volitional tracking eye movement. We studied ocular following, a reflexive tracking eye movement, simultaneously measuring eye movement direction and perceived direction of a moving random dot field. Oculomotor errors were largest for near-cardinal directions, providing the first evidence for cardinal repulsion in reflexive eye movements. Biases in perceptual and oculomotor errors were correlated across test directions, but not across single trials with the same direction. Based on the similar direction-dependent anisotropies in eye movements and perception, there is reason to believe that partially overlapping populations of sensory neurons underlie motion perception and oculomotor behaviors, with independent downstream sources of noise masking trial-by-trial correlations between perception and action. |
Hazel I. Blythe; Rebecca L. Johnson; Simon P. Liversedge; Keith Rayner Reading transposed text: effects of transposed letter distance and consonant-vowel status on eye movements Journal Article In: Attention, Perception, & Psychophysics, vol. 76, no. 8, pp. 2424–2440, 2014. @article{Blythe2014, Two experiments were conducted to investigate the flexibility of letter-position encoding in word identification during reading. In both experiments, two tasks were used. First, participants' eye movements were measured as they read sentences containing transposed letter (TL) strings. Second, participants were presented with the TL strings in isolation and were asked to discriminate them from nonwords. In Experiment 1, we manipulated the distance between transposed letters (ligament vs. liagment vs. limagent vs. lieamgnt). Reading/response times increased with the distance between TLs. In Experiment 2, we manipulated whether the TLs were consonants, vowels, or one of each (ssytem vs. faeture vs. fromat). Reading/response times showed that CV transpositions were the most disruptive. In both experiments, response accuracy was particularly poor for words presented in isolation when there was an intervening letter between TLs. These data show that processing across multiple fixations, and the presence of a meaningful sentence context, are important for flexible letter position encoding in lexical identification. |
Sheena K. Au-Yeung; Johanna K. Kaakinen; Valerie Benson Cognitive perspective-taking during scene perception in autism spectrum disorder: Evidence from eye movements Journal Article In: Autism Research, vol. 7, no. 1, pp. 84–93, 2014. @article{AuYeung2014, The present study examined how eye movements during scene viewing are modulated by adopting psychological perspectives in both adults with autism spectrum disorders (ASD) and typically developing adults. In the current study, participants viewed house scenes with either non-perspective-taking (look for valuable items/features of the house that need fixing) or perspective-taking instructions (imagine that you are a burglar/repairman) while their eye movements were recorded. The eye movement measures revealed that for the “look for the valuable items” and burglar perspective task, the ASD group showed typical relevance effects (the preference to look at schema-relevant compared with schema-irrelevant targets) in their eye movements. However, we found subtle processing differences between the groups that were related to initial orienting to and processing of schema-relevant items for the “look for the features that need fixing” and the repairman perspective-taking task. There was an absence of a relevance effect for the ASD group for the repairman perspective and its non-perspective-taking equivalent instruction showing that the identification of items relevant to those schemas was more difficult for the ASD group. The present findings suggest that resolving ambiguity may be a defining feature of complex information processing deficits in ASD. |
Reza Azadi; Mark R. Harwood Visual cues that are effective for contextual saccade adaptation Journal Article In: Journal of Neurophysiology, vol. 111, no. 11, pp. 2307–2319, 2014. @article{Azadi2014, The accuracy of saccades, as maintained by saccade adaptation, has been shown to be context dependent: able to have different amplitude movements to the same retinal displacement dependent on motor contexts such as orbital starting location. There is conflicting evidence as to whether purely visual cues also effect contextual saccade adaptation and, if so, what function this might serve. We tested what visual cues might evoke contextual adaptation. Over 5 experiments, 78 naive subjects made saccades to circularly moving targets, which stepped outward or inward during the saccade depending on target movement direction, speed, or color and shape. To test if the movement or context postsaccade were critical, we stopped the postsaccade target motion ( experiment 4 ) or neutralized the contexts by equating postsaccade target speed to an intermediate value ( experiment 5 ). We found contextual adaptation in all conditions except those defined by color and shape. We conclude that some, but not all, visual cues before the saccade are sufficient for contextual adaptation. We conjecture that this visual contextuality functions to allow for different motor states for different coordinated movement patterns, such as coordinated saccade and pursuit motor planning. |
Raiju J. Babu; Susan J. Leat; Elizabeth L. Irving Effect of age and pop out distracter on attended field of view Journal Article In: Journal of Optometry, vol. 7, pp. 229–237, 2014. @article{Babu2014, Purpose: To investigate the functional field of view (FFOV) of younger and older individuals using the attended field of view (AFOV), a method which allows for eye and head movement. The impact of a pop out distracter and a dual task on the FFOV measure was also investigated. Methods: Nine young adult (25 ± 6 years) and 9 older participants (72 ± 4 years) took part in the experiment. The AFOV test involved the binocular detection and localization of a white target (Landolt-C) in a field of 24 white rings (distracters). The further AFOV tests were modified to include the presence of a pop out distracter, a dual task condition, and a combination of the two. Results: Older observers had lower viewing efficiency (log [1/presentation time]) in all con- ditions (pooled mean across conditions: older: 0.05 ± 0.02; younger: 0.48 ± 0.04) than the younger group. The addition of dual or a pop out distracter did not affect the older group (mean difference ∼104 ± 150 ms and ∼124 ± 122 ms respectively) but the additional pop out distracter reduced the efficiency of the younger group for targets near fixation (mean difference ∼68 ± 35 ms). Conclusion: Better viewing efficiency was observed in younger individuals compared to older individuals. Difficulty in disregarding irrelevant stimuli and thereby resorting to inefficient search strategy is proposed as the reason for the differences. The finding that both older and younger individuals are not affected significantly by the presence of the irrelevant pop out distracter has implications in situations such as driving or hazard avoidance. In such scenarios, search performance is likely not impaired beyond what is found with distracters (visual clutter) in the environment. |
Dong-Hyun Baek; Jeyeon Lee; Hang Byeon; Hoseok Choi; In Young Kim; Kyoung-Min Lee; James Jungho Pak; Dong Pyo Jang; Sang-Hoon Lee A thin film polyimide mesh microelectrode for chronic epidural electrocorticography recording with enhanced contactability Journal Article In: Journal of Neural Engineering, vol. 11, no. 4, pp. 1–10, 2014. @article{Baek2014, Objective. Epidural electrocorticography (ECoG) activity may be more reliable and stable than single-unit-activity or local field potential. Invasive brain computer interface (BCI) devices are limited by mechanical mismatching and cellular reactive responses due to differences in the elastic modulus and the motion of stiff electrodes. We propose a mesh-shaped electrode to enhance the contactability between surface of dura and electrode. Approach. We designed a polyimide (PI) electrode with a mesh pattern for more conformal contact with a curved surface. We compared the contact capability of mesh PI electrodes with conventionally used sheet PI electrode. The electrical properties of the mesh PI electrode were evaluated for four weeks. We recorded the epidural ECoG (eECoG) activity on the surface of rhesus monkey brains while they performed a saccadic task for four months. Main results. The mesh PI electrode showed good contact with the agarose brain surface, as evaluated by visual inspection and signal measurement. It was about 87% accurate in predicting the direction of saccade eye movement. Significance. Our results indicate that the mesh PI electrode was flexible and good contact on the curved surface and can record eECoG activity maintaining close contact to dura, which was proved by in vivo and in vitro test. |
Daniel Baldauf; Robert Desimone Neural mechanisms of object-based attention Journal Article In: Science, vol. 344, no. 6182, pp. 424–427, 2014. @article{Baldauf2014, How we attend to objects and their features that cannot be separated by location is not understood. We presented two temporally and spatially overlapping streams of objects, faces versus houses, and used magnetoencephalography and functional magnetic resonance imaging to separate neuronal responses to attended and unattended objects. Attention to faces versus houses enhanced the sensory responses in the fusiform face area (FFA) and parahippocampal place area (PPA), respectively. The increases in sensory responses were accompanied by induced gamma synchrony between the inferior frontal junction, IFJ, and either FFA or PPA, depending on which object was attended. The IFJ appeared to be the driver of the synchrony, as gamma phases were advanced by 20 ms in IFJ compared to FFA or PPA. Thus, the IFJ may direct the flow of visual processing during object-based attention, at least in part through coupled oscillations with specialized areas such as FFA and PPA. W |
D. A. Barany; V. Della-Maggiore; Shivakumar Viswanathan; M. Cieslak; Scott T. Grafton Feature Iinteractions enable decoding of sensorimotor transformations for goal-directed movement Journal Article In: Journal of Neuroscience, vol. 34, no. 20, pp. 6860–6873, 2014. @article{Barany2014, Neurophysiology and neuroimaging evidence shows that the brain represents multiple environmental and body-related features to compute transformations from sensory input to motor output. However, it is unclear how these features interact during goal-directed movement. To investigate this issue, we examined the representations of sensory and motor features of human hand movements within the left-hemisphere motor network. In a rapid event-related fMRI design, we measured cortical activity as participants performed right-handed movements at the wrist, with either of two postures and two amplitudes, to move a cursor to targets at different locations. Using a multivoxel analysis technique with rigorous generalization tests, we reliably distinguished representations of task-related features (primarily target location, movement direction, and posture) in multiple regions. In particular, we identified an interaction between target location and movement direction in the superior parietal lobule, which may underlie a transformation from the location of the target in space to a movement vector. In addition, we found an influence of posture on primary motor, premotor, and parietal regions. Together, these results reveal the complex interactions between different sensory and motor features that drive the computation of sensorimotor transformations. |
Ellen Gurman Bard; Robin L. Hill; Mary Ellen Foster; Manabu Arai Tuning accessibility of referring expressions in situated dialogue Journal Article In: Language, Cognition and Neuroscience, vol. 29, no. 8, pp. 928–949, 2014. @article{Bard2014, Accessibility theory associates more complex referring expressions with less accessible referents. Felicitous referring expressions should reflect accessibility from the addressee's perspective, which may be difficult for speakers to assess incrementally. If mechanisms shared by perception and production help interlocutors align internal representations, then dyads with different roles and different things to say should profit less from alignment. We examined introductory mentions of on-screen shapes within a joint task for effects of access to the addressee's attention, of players' actions and of speakers' roles. Only speakers' actions affected the form of referring expression and only different role dyads made egocentric use of actions hidden from listeners. Analysis of players' gaze around referring expressions confirmed this pattern; only same role dyads coordinated attention as the accessibility theory predicts. The results are discussed within a model distributing collaborative effort under the cons... |
Anthony S. Barnhart; Stephen D. Goldinger Blinded by magic: Eye-movements reveal the misdirection of attention Journal Article In: Frontiers in Psychology, vol. 5, pp. 1461, 2014. @article{Barnhart2014, Recent studies (e.g., Kuhn and Tatler, 2005) have suggested that magic tricks can provide a powerful and compelling domain for the study of attention and perception. In particular, many stage illusions involve attentional misdirection, guiding the observer's gaze to a salient object or event, while another critical action, such as sleight of hand, is taking place. Even if the critical action takes place in full view, people typically fail to see it due to inattentional blindness (IB). In an eye-tracking experiment, participants watched videos of a new magic trick, wherein a coin placed beneath a napkin disappears, reappearing under a different napkin. Appropriately deployed attention would allow participants to detect the "secret" event that underlies the illusion (a moving coin), as it happens in full view and is visible for approximately 550 ms. Nevertheless, we observed high rates of IB. Unlike prior research, eye-movements during the critical event showed different patterns for participants, depending upon whether they saw the moving coin. The results also showed that when participants watched several "practice" videos without any moving coin, they became far more likely to detect the coin in the critical trial. Taken together, the findings are consistent with perceptual load theory (Lavie and Tsal, 1994). |
Dale J. Barr; Laura Jackson; Isobel Phillips Using a voice to put a name to a face: The psycholinguistics of proper name comprehension Journal Article In: Journal of Experimental Psychology: General, vol. 143, no. 1, pp. 404–413, 2014. @article{Barr2014, We propose that hearing a proper name (e.g., Kevin) in a particular voice serves as a compound memory cue that directly activates representations of a mutually known target person, often permitting reference resolution without any complex computation of shared knowledge. In a referential communication study, pairs of friends played a communication game, in which we monitored the eyes of one friend (the addressee) while he or she sought to identify the target person, in a set of four photos, on the basis of a name spoken aloud. When the name was spoken by a friend, addressees rapidly identified the target person, and this facilitation was independent of whether the friend was articulating a message he or she had designed versus one from a third party with whom the target person was not shared. Our findings suggest that the comprehension system takes advantage of regularities in the environment to minimize effortful computation about who knows what. |
Pablo A. Barrionuevo; Nathaniel Nicandro; J. Jason McAnany; Andrew J. Zele; Paul Gamlin; Dingcai Cao Assessing rod, cone, and melanopsin contributions to human pupil flicker responses Journal Article In: Investigative Ophthalmology & Visual Science, vol. 55, no. 2, pp. 719–727, 2014. @article{Barrionuevo2014, PURPOSE: We determined the relative contributions of rods, cones, and melanopsin to pupil responses in humans using temporal sinusoidal stimulation for light levels spanning the low mesopic to photopic range. METHODS: A four-primary Ganzfeld photostimulator controlled flicker stimulations at seven light levels (-2.7 to 2 log cd/m(2)) and five frequencies (0.5-8 Hz). Pupil diameter was measured using a high-resolution eye tracker. Three kinds of sinusoidal photoreceptor modulations were generated using silent substitution: rod modulation, cone modulation, and combined rod and cone modulation in phase (experiment 1) or cone phase shifted (experiment 2) from a fixed rod phase. The melanopsin excitation was computed for each condition. A vector sum model was used to estimate the relative contribution of rods, cones, and melanopsin to the pupil response. RESULTS: From experiment 1, the pupil frequency response peaked at 1 Hz at two mesopic light levels for the three modulation conditions. Analyzing the rod-cone phase difference for the combined modulations (experiment 2) identified a V-shaped response amplitude with a minimum between 135° and 180°. The pupil response phases increased as cone modulation phase increased. The pupil amplitude increased with increasing light level for cone, and combined (in-phase rod and cone) modulation, but not for the rod modulation. CONCLUSIONS: These results demonstrate that cone- and rod-pathway contributions are more predominant than melanopsin contribution to the phasic pupil response. The combined rod, cone, and melanopsin inputs to the phasic state of the pupil light reflex follow linear summation. |
Rebecca L. Bassett-Gunter; Amy E. Latimer-Cheung; Kathleen A. Martin Ginis; Monica S. Castelhano I spy with my little eye: Cognitive processing of framed physical activity messages Journal Article In: Journal of Health Communication, vol. 19, no. 6, pp. 676–691, 2014. @article{BassettGunter2014, The primary purpose was to examine the relative cognitive processing of gain-framed versus loss-framed physical activity messages following exposure to health risk information. Guided by the Extended Parallel Process Model, the secondary purpose was to examine the relation between dwell time, message recall, and message-relevant thoughts, as well as perceived risk, personal relevance, and fear arousal. Baseline measures of perceived risk for inactivity-related disease and health problems were administered to 77 undergraduate students. Participants read population-specific health risk information while wearing a head-mounted eye tracker, which measured dwell time on message content. Perceived risk was then reassessed. Next, participants read PA messages while the eye tracker measured dwell time on message content. Immediately following message exposure, recall, thought-listing, fear arousal, and personal relevance were measured. Dwell time on gain-framed messages was significantly greater than loss-framed messages. However, message recall and thought-listing did not differ by message frame. Dwell time was not significantly related to recall or thought-listing. Consistent with the Extended Parallel Process Model, fear arousal was significantly related to recall, thought-listing, and personal relevance. In conclusion, gain-framed messages may evoke greater dwell time than loss-famed messages. However, dwell time alone may be insufficient for evoking further cognitive processing |
Oliver Baumann; Jason B. Mattingley Effects of attention and perceptual uncertainty on cerebellar activity during visual motion perception Journal Article In: Cerebellum, vol. 13, no. 1, pp. 46–54, 2014. @article{Baumann2014, Recent clinical and neuroimaging studies have revealed that the human cerebellum plays a role in visual motion perception, but the nature of its contribution to this function is not understood. Some reports suggest that the cerebellum might facilitate motion perception by aiding attentive tracking of visual objects. Others have identified a particular role for the cerebellum in discriminating motion signals in perceptually uncertain conditions. Here, we used functional magnetic resonance imaging to determine the degree to which cerebellar involvement in visual motion perception can be explained by a role in sustained attentive tracking of moving stimuli in contrast to a role in visual motion discrimination. While holding the visual displays constant, we manipulated attention by having participants attend covertly to a field of random-dot motion or a colored spot at fixation. Perceptual uncertainty was manipulated by varying the percentage of signal dots contained within the random-dot arrays. We found that attention to motion under high perceptual uncertainty was associated with strong activity in left cerebellar lobules VI and VII. By contrast, attending to motion under low perceptual uncertainty did not cause differential activation in the cerebellum. We found no evidence to support the suggestion that the cerebellum is involved in simple attentive tracking of salient moving objects. Instead, our results indicate that specific subregions of the cerebellum are involved in facilitating the detection and discrimination of task-relevant moving objects under conditions of high perceptual uncertainty. We conclude that the cerebellum aids motion perception under conditions of high perceptual demand. |
Carol L. Baym; Naiman A. Khan; Jim M. Monti; Lauren B. Raine; Eric S. Drollette; R. Davis Moore; Mark R. Scudder; Arthur F. Kramer; Charles H. Hillman; Neal J. Cohen Dietary lipids are differentially associated with hippocampal-dependent relational memory in prepubescent children Journal Article In: American Journal of Clinical Nutrition, vol. 99, no. 5, pp. 1026–1033, 2014. @article{Baym2014, BACKGROUND: Studies in rodents and older humans have shown that the hippocampus-a brain structure critical to relational/associative memory-has remarkable plasticity as a result of lifestyle factors (eg, exercise). However, the effect of dietary intake on hippocampal-dependent memory during childhood has remained unexamined.$backslash$n$backslash$nOBJECTIVE: We investigated the cross-sectional relation of dietary components characteristic of the Western diet, including saturated fatty acids (SFAs), omega-3 (n-3) fatty acids, and refined sugar, with hippocampal-dependent relational memory in prepubescent children.$backslash$n$backslash$nDESIGN: Participants aged 7-9 y (n = 52) reported their dietary intake by using the Youth-Adolescent Food-Frequency Questionnaire and completed memory tasks designed to assess relational (hippocampal-dependent) and item (hippocampal-independent) memory. Performance on the memory tasks was assessed with both direct (accuracy) and indirect (eye movement) measures.$backslash$n$backslash$nRESULTS: Partial correlations adjusted for body mass index showed a positive relation between relational memory accuracy and intake of omega-3 fatty acids and a negative relation of both relational and item memory accuracy with intake of SFAs. Potential confounding factors of age, sex, intelligence quotient, socioeconomic status, pubertal timing, and aerobic fitness (maximal oxygen volume) were not significantly related to any of the dietary intake measures. Eye movement measures of relational memory (preferential viewing to the target stimulus) showed a negative relation with intake of added sugar.$backslash$n$backslash$nCONCLUSIONS: SFA intake was negatively associated with both forms of memory, whereas omega-3 fatty acid intake was selectively positively associated with hippocampal-dependent relational memory. These findings are among the first to show a link between habitual dietary intake and cognitive health as pertaining to hippocampal function in childhood. |
Paul M. Bays Noise in neural populations accounts for errors in working memory Journal Article In: Journal of Neuroscience, vol. 34, no. 10, pp. 3632–3645, 2014. @article{Bays2014, Errors in short-term memory increase with the quantity of information stored, limiting the complexity of cognition and behavior. In visual memory, attempts to account for errors in terms of allocation of a limited pool of working memory resources have met with some success, but the biological basis for this cognitive architecture is unclear. An alternative perspective attributes recall errors to noise in tuned populations of neurons that encode stimulus features in spiking activity. I show that errors associated with decreasing signal strength in probabilistically spiking neurons reproduce the pattern of failures in human recall under increasing memory load. In particular, deviations from the normal distribution that are characteristic of working memory errors and have been attributed previously to guesses or variability in precision are shown to arise as a natural consequence of decoding populations of tuned neurons. Observers possess fine control over memory representations and prioritize accurate storage of behaviorally relevant information, at a cost to lower priority stimuli. I show that changing the input drive to neurons encoding a prioritized stimulus biases population activity in a manner that reproduces this empirical tradeoff in memory precision. In a task in which predictive cues indicate stimuli most probable for test, human observers use the cues in an optimal manner to maximize performance, within the constraints imposed by neural noise. |
Olivia Beaudry; Annie Roy-Charland; Melanie Perron; Isabelle Cormier; Roxane Tapp Featural processing in recognition of emotional facial expressions Journal Article In: Cognition and Emotion, vol. 28, no. 3, pp. 416–432, 2014. @article{Beaudry2014, The present study aimed to clarify the role played by the eye/brow and mouth areas in the recognition of the six basic emotions. In Experiment 1, accuracy was examined while participants viewed partial and full facial expressions; in Experiment 2, participants viewed full facial expressions while their eye movements were recorded. Recognition rates were consistent with previous research: happiness was highest and fear was lowest. The mouth and eye/brow areas were not equally important for the recognition of all emotions. More precisely, while the mouth was revealed to be important in the recognition of happiness and the eye/brow area of sadness, results are not as consistent for the other emotions. In Experiment 2, consistent with previous studies, the eyes/brows were fixated for longer periods than the mouth for all emotions. Again, variations occurred as a function of the emotions, the mouth having an important role in happiness and the eyes/brows in sadness. The general pattern of results for the other four emotions was inconsistent between the experiments as well as across different measures. The complexity of the results suggests that the recognition process of emotional facial expressions cannot be reduced to a simple feature processing or holistic processing for all emotions. |
Genna M. Bebko; Steven L. Franconeri; Kevin N. Ochsner; Joan Y. Chiao Attentional deployment is not necessary for successful emotion regulation via cognitive reappraisal or expressive suppression Journal Article In: Emotion, vol. 14, no. 3, pp. 504–512, 2014. @article{Bebko2014, According to appraisal theories of emotion, cognitive reappraisal is a successful emotion regulation strategy because it involves cognitively changing our thoughts, which, in turn, change our emotions. However, recent evidence has challenged the importance of cognitive change and, instead, has suggested that attentional deployment may at least partly explain the emotion regulation success of cognitive reappraisal. The purpose of the current study was to examine the causal relationship between attentional deployment and emotion regulation success. We examined 2 commonly used emotion regulation strategies-cognitive reappraisal and expressive suppression-because both depend on attention but have divergent behavioral, experiential, and physiological outcomes. Participants were either instructed to regulate emotions during free-viewing (unrestricted image viewing) or gaze-controlled (restricted image viewing) conditions and to self-report negative emotional experience. For both emotion regulation strategies, emotion regulation success was not altered by changes in participant control over the (a) direction of attention (free-viewing vs. gaze-controlled) during image viewing and (b) valence (negative vs. neutral) of visual stimuli viewed when gaze was controlled. Taken together, these findings provide convergent evidence that attentional deployment does not alter subjective negative emotional experience during either cognitive reappraisal or expressive suppression, suggesting that strategy-specific processes, such as cognitive appraisal and response modulation, respectively, may have a greater impact on emotional regulation success than processes common to both strategies, such as attention. |
Elizabeth H. Beck; Anthony A. Amato; Steven A. Greenberg; Elizabeth H. Beck Improvement of internuclear ophthalmoparesis in multiple sclerosis with dalfampridine Journal Article In: Neurology, vol. 83, pp. 192–194, 2014. @article{Beck2014, Internuclear ophthalmoparesis (INO) in multiple sclerosis (MS) is due to demyelination of the medial longitudinal fasciculus (MLF) and provides an acces- sible model for studying consequences of raised body temperature and fatigue on central demyelination.1,2 Prompted by one of our patient's report of vision improvement after initiating dalfampridine, a potas- sium channel blocker prescribed for gait impairment,3 we measured this drug's effects on 3 patients with MS with bilateral INO. All showed changes in horizontal saccadic conjugacy consistent with improved trans- mission of the neural pulse responsible for adducting movements. |
Melissa R. Beck; S. Lee Hong; Amanda E. Lamsweerde; Justin M. Ericson In: PLoS ONE, vol. 9, no. 4, pp. e94539, 2014. @article{Beck2014a, Responses are quicker to predictable stimuli than if the time and place of appearance is uncertain. Studies that manipulate target predictability often involve overt cues to speed up response times. However, less is known about whether individuals will exhibit faster response times when target predictability is embedded within the inter-trial relationships. The current research examined the combined effects of spatial and temporal target predictability on reaction time (RT) and allocation of overt attention in a sustained attention task. Participants responded as quickly as possible to stimuli while their RT and eye movements were measured. Target temporal and spatial predictability were manipulated by altering the number of: 1) different time intervals between a response and the next target; and 2) possible spatial locations of the target. The effects of target predictability on target detection (Experiment 1) and target discrimination (Experiment 2) were tested. For both experiments, shorter RTs as target predictability increased across both space and time were found. In addition, the influences of spatial and temporal target predictability on RT and the overt allocation of attention were task dependent; suggesting that effective orienting of attention relies on both spatial and temporal predictability. These results indicate that stimulus predictability can be increased without overt cues and detected purely through inter-trial relationships over the course of repeated stimulus presentations. |
Paul M. J. Thomas; Margaret C. Jackson; Jane E. Raymond A threatening face in the crowd: Effects of emotional singletons on visual working memory Journal Article In: Journal of Experimental Psychology: Human Perception and Performance, vol. 40, no. 1, pp. 253–263, 2014. @article{Thomas2014, Faces with threatening versus positive expressions are better remembered in visual working memory (WM) and are especially effective at capturing attention. We asked how the presence of a single threatening or happy face affects WM for concurrently viewed faces with neutral expressions. If threat captures attention and attention determines WM, then a WM performance cost for neutral faces should be evident. However, if threat boosts processing in an object-specific, noncompetitive manner, then no such costs should be produced. Participants viewed three neutral and one angry or happy face for 2 s. Face recognition was tested 1 s later. Although WM was better for singletons than nonsingletons and better for angry versus happy singletons, WM for neutral faces remained unaffected by either singleton. These results, combined with eye movement and response time analyses, argue against a selective attention account of threat-based benefits to WM and support object-specific enhancement via threat processing. |
Aidan A. Thompson; Patrick A. Byrne; Denise Y. P. Henriques Visual targets aren't irreversibly converted to motor coordinates: Eye-centered updating of visuospatial memory in online reach control Journal Article In: PLoS ONE, vol. 9, no. 3, pp. e92455, 2014. @article{Thompson2014, Counter to current and widely accepted hypotheses that sensorimotor transformations involve converting target locations in spatial memory from an eye-fixed reference frame into a more stable motor-based reference frame, we show that this is not strictly the case. Eye-centered representations continue to dominate reach control even during movement execution; the eye-centered target representation persists after conversion to a motor-based frame and is continuously updated as the eyes move during reach, and is used to modify the reach plan accordingly during online control. While reaches are known to be adjusted online when targets physically shift, our results are the first to show that similar adjustments occur in response to changes in representations of remembered target locations. Specifically, we find that shifts in gaze direction, which produce predictable changes in the internal (specifically eye-centered) representation of remembered target locations also produce mid-transport changes in reach kinematics. This indicates that representations of remembered reach targets (and visuospatial memory in general) continue to be updated relative to gaze even after reach onset. Thus, online motor control is influenced dynamically by both the external and internal updating mechanisms. |
Jennifer G. Tichon; Timothy Mavin; Guy Wallis; Troy A. W. Visser; Stephan Riek Using pupillometry and electromyography to track positive and negative affect during flight simulation Journal Article In: Aviation Psychology and Applied Human Factors, vol. 4, no. 1, pp. 23–32, 2014. @article{Tichon2014, Affect is a key determinant of performance, due to its influence on cognitive processing. Negative emotions such as anxiety are recognized cognitive stressors shown to degrade decision making and situation awareness. Conversely, positive affect can improve problem solving and facilitate recall. This exploratory pilot study used electromyography and pupillometry measures to track pilots' levels of negative and positive affect while training in a flight simulator. Fixation duration and saccade rate were found to correspond reliably to pilot self-reports of anxiety. Additionally, large increases in muscle activation were also recorded when higher anxiety was reported. Decreases in positive affect correlated significantly with saccade rate, fixation duration, and mean saccade velocity. Results are discussed in terms of using psychophysiological measures to provide a continuous, objective measure of pilot affective levels as an additional evaluation method to support assessment of pilot performance in simulation training environments. |
Jennifer G. Tichon; Guy Wallis; Stephan Riek; Timothy Mavin Physiological measurement of anxiety to evaluate performance in simulation training Journal Article In: Cognition, Technology and Work, vol. 16, no. 2, pp. 203–210, 2014. @article{Tichon2014a, The ability to control emotion is a skill which contributes to performance in the same way as cognitive and technical skills do to the successful completion of high stress operations. The interdependence between emotion, problem-solving and decision-making makes a negative emotion such as anxiety of interest in evaluating trainee performance in simulations which replicate stressful work conditions. Self-report measures of anxiety require trainees to interrupt the simulation experience to either complete psychological scales or make verbal reports of state anxiety. An uninterrupted, continuous measure of anxiety is, therefore, preferable for simulation environments. During this study, the anxiety levels of trainee pilots were tracked via electromyography, eye movements and pupillometry while undertaking required tasks in a flight simulation. Fixation duration and saccade rate corresponded reliably to pilot self-reports of anxiety, while pupil size and saccade amplitude did not show a strong comparison to changes in affective state. Large increases in muscle activation where recorded when higher anxiety was reported. The results suggest that a combination of physiological measures could provide a robust, continuous indicator of anxiety level. The implications of the current study on further development of physiological measures to support tracking anxiety as a tool for simulation training assessment are discussed. © 2013 Springer-Verlag London. |
Jianliang Tong; Jun Maruta; Kristin J. Heaton; Alexis L. Maule; Jamshid Ghajar Adaptation of visual tracking synchronization after one night of sleep deprivation Journal Article In: Experimental Brain Research, vol. 232, no. 1, pp. 121–131, 2014. @article{Tong2014, The temporal delay between sensory input and motor execution is a fundamental constraint in interactions with the environment. Predicting the temporal course of a stimulus and dynamically synchronizing the required action with the stimulus are critical for offsetting this constraint, and this prediction-synchronization capacity can be tested using visual tracking of a target with predictable motion. Although the role of temporal prediction in visual tracking is assumed, little is known of how internal predictions interact with the behavioral outcome or how changes in the cognitive state influence such interaction. We quantified and compared the predictive visual tracking performance of military volunteers before and after one night of sleep deprivation. The moment-to-moment synchronization of visual tracking during sleep deprivation deteriorated with sensitivity changes greater than 40 %. However, increased anticipatory saccades maintained the overall temporal accuracy with near zero phase error. Results suggest that acute sleep deprivation induces instability in visuomotor prediction, but there is compensatory visuomotor adaptation. Detection of these visual tracking features may aid in the identification of insufficient sleep. |
Alisha Siebold; Mieke Donk On the importance of relative salience: Comparing overt selection behavior of single versus simultaneously presented stimuli Journal Article In: PLoS ONE, vol. 9, no. 6, pp. e99707, 2014. @article{Siebold2014, The goal of the current study was to investigate time-dependent effects of the number of targets presented and its interaction with stimulus salience on oculomotor selection performance. To this end, observers were asked to make a speeded eye movement to a target orientation singleton embedded in a homogeneous background of vertically oriented lines. In Experiment 1, either one or two physically identical targets were presented, whereas in Experiment 2 an additional orientation-based salience manipulation was performed. The results showed that the probability of a singleton being available for selection is reduced in the presence of an identical singleton (Experiment 1) and that this effect is modulated by the salience of the other singleton (Experiment 2). While the absolute orientation contrast of a target relative to the background contributed to the probability that it is available for selection, the crucial factor affecting selection was the relative salience between singletons. These findings are incompatible with a processing speed account, which highlights the importance of visibility and claims that a certain singleton identity has a unique speed with which it can be processed. In contrast, the finding that the number of targets presented affected a target's availability suggests an important role of the broader display context in determining oculomotor selection performance. |
Alisha Siebold; Mieke Donk Reinstating salience effects over time: The influence of stimulus changes on visual selection behavior over a sequence of eye movements Journal Article In: Attention, Perception, & Psychophysics, vol. 76, no. 6, pp. 1655–1670, 2014. @article{Siebold2014a, Recently, we showed that salience affects initial saccades only in a static stimulus environment; subsequent saccades were unaffected by salience but, instead, were directed in line with task requirements (Siebold, van Zoest, & Donk, PLoS ONE 6(9): e23552, 2011). Yet multiple studies have shown that people tend to fixate salient regions more often than nonsalient ones when they are looking at images-in particular, when salience is defined by dynamic changes. The goal of the present study was to investigate how oculomotor selection beyond an initial saccade is affected by salience as derived from changing, as opposed to static, stimuli. Observers were presented with displays containing two fixation dots, one target, one distractor, and multiple background elements. They were instructed to fixate on one of the fixation dots and make a speeded eye movement to the target, either directly or preceded by an initial eye movement to the other fixation dot. In Experiment 1, target and distractor differed in orientation contrast relative to the background, such that one was more salient than the other, whereas in Experiments 2 and 3, the orientation contrast between the two elements was identical. Here, salience was implemented by a continuous luminance flicker or by a difference in luminance contrast, respectively, which was presented either simultaneously with display onset or contingent upon the first saccade. The results showed that in all experiments, initial saccades were strongly guided by salience, whereas second saccades were consistently goal directed if the salience manipulation was present from display onset. However, if the flicker or luminance contrast was presented contingent upon the initial saccade, salience effects were reinstated. We argue that salience effects are short-lived but can be reinstated if new information is presented, even when this occurs during an eye movement. |
Eva Siegenthaler; Francisco M. Costela; Michael B. Mccamy; Leandro Luigi Di Stasi; Jorge Otero-Millan; Andreas Sonderegger; Rudolf Groner; Stephen L. Macknik; Susana Martinez-Conde Task difficulty in mental arithmetic affects microsaccadic rates and magnitudes Journal Article In: European Journal of Neuroscience, vol. 39, no. 2, pp. 287–294, 2014. @article{Siegenthaler2014, Microsaccades are involuntary, small-magnitude saccadic eye movements that occur during attempted visual fixation. Recent research has found that attention can modulate microsaccade dynamics, but few studies have addressed the effects of task difficulty on microsaccade parameters, and those have obtained contradictory results. Further, no study to date has investigated the influence of task difficulty on microsaccade production during the performance of non-visual tasks. Thus, the effects of task difficulty on microsaccades, isolated from sensory modality, remain unclear. Here we investigated the effects of task difficulty on microsaccades during the performance of a non-visual, mental arithmetic task with two levels of complexity. We found that microsaccade rates decreased and microsaccade magnitudes increased with increased task difficulty. We propose that changes in microsaccade rates and magnitudes with task difficulty are mediated by the effects of varying attentional inputs on the rostral superior colliculus activity map. |
Heida M. Sigurdardottir; Suzanne M. Michalak; David L. Sheinberg Shape beyond recognition: Form-derived directionality and its effects on visual attention and motion perception Journal Article In: Journal of Experimental Psychology: General, vol. 143, no. 1, pp. 434–454, 2014. @article{Sigurdardottir2014, The shape of an object restricts its movements and therefore its future location. The rules governing selective sampling of the environment likely incorporate any available data, including shape, that provide information about where important things are going to be in the near future so that the object can be located, tracked, and sampled for information. We asked people to assess in which direction several novel objects pointed or directed them. With independent groups of people, we investigated whether their attention and sense of motion were systematically biased in this direction. Our work shows that nearly any novel object has intrinsic directionality derived from its shape. This shape information is swiftly and automatically incorporated into the allocation of overt and covert visual orienting and the detection of motion, processes that themselves are inherently directional. The observed connection between form and space suggests that shape processing goes beyond recognition alone and may help explain why shape is a relevant dimension throughout the visual brain. |
J. D. Silvis; Stefan Van der Stigchel How memory mechanisms are a key component in the guidance of our eye movements: Evidence from the global effect Journal Article In: Psychonomic Bulletin & Review, vol. 21, no. 2, pp. 357–362, 2014. @article{Silvis2014, Investigating eye movements has been a promising approach to uncover the role of visual working memory in early attentional processes. Prior research has already demonstrated that eye movements in search tasks are more easily drawn toward stimuli that show similarities to working memory content, as compared with neutral stimuli. Previous saccade tasks, however, have always required a selection process, thereby automatically recruiting working memory. The present study was an attempt to confirm the role of working memory in oculomotor selection in an unbiased saccade task that rendered memory mechanisms irrelevant. Participants executed a saccade in a display with two elements, without any instruction to aim for one particular element. The results show that when two objects appear simultaneously, a working memory match attracts the first saccade more profoundly than do mismatch objects, an effect that was present throughout the saccade latency distribution. These findings demonstrate that memory plays a fundamental biasing role in the earliest competitive processes in the selection of visual objects, even when working memory is not recruited during selection. |
Jeroen D. Silvis; Mieke Donk The effects of saccade-contingent changes on oculomotor capture: Salience is important even beyond the first oculomotor response Journal Article In: Attention, Perception, & Psychophysics, vol. 76, no. 6, pp. 1803–1814, 2014. @article{Silvis2014a, Whenever a novel scene is presented, visual salience merely plays a transient role in oculomotor selection. Unique stimulus properties, such as a distinct and, thereby, salient color, affect the oculomotor response only when observers react relatively quickly. For slower responses, or for consecutive ones, salience-driven effects appear completely absent. To date, however, the circumstances that may reinstate the effects of salience over multiple eye movements are still unclear. Recent research shows that changes to a scene can attract gaze, even when these changes occur without a transient signal (i.e., during an eye movement). The aim of the present study was to investigate whether this capture is mediated through salience-driven or memory-guided processes. In three experiments, we examined how the nature of a change in salience that occurred during an eye movement affected consecutive saccades. The results demonstrate that the oculomotor system is exclusively susceptible to increases in salience from one fixation to the next, but only when these increases result in a uniquely high salience level. This suggests that even in the case of a saccade-contingent change, oculomotor selection behavior can be affected by salience-driven mechanisms, possibly to allow the automatic detection of uniquely distinct objects at any moment. The results and implications will be discussed in relation to current views on visual selection. |
Jedediah M. Singer; Gabriel Kreiman Short temporal asynchrony disrupts visual object recognition Journal Article In: Journal of vision, vol. 14, no. 5, pp. 1–14, 2014. @article{Singer2014, Humans can recognize objects and scenes in a small fraction of a second. The cascade of signals underlying rapid recognition might be disrupted by temporally jittering different parts of complex objects. Here we investigated the time course over which shape information can be integrated to allow for recognition of complex objects. We presented fragments of object images in an asynchronous fashion and behaviorally evaluated categorization performance. We observed that visual recognition was significantly disrupted by asynchronies of approximately 30 ms, suggesting that spatiotemporal integration begins to break down with even small deviations from simultaneity. However, moderate temporal asynchrony did not completely obliterate recognition; in fact, integration of visual shape information persisted even with an asynchrony of 100 ms. We describe the data with a concise model based on the dynamic reduction of uncertainty about what image was presented. These results emphasize the importance of timing in visual processing and provide strong constraints for the development of dynamical models of visual shape recognition. |
Chandan Singh; Dhananjay Yadav; Jinho Lee Reader comprehension ranking by monitoring eye gaze using eye tracker Journal Article In: International Journal of Intelligent Systems Technologies and Applications, vol. 13, no. 4, pp. 294–307, 2014. @article{Singh2014, This paper concentrates on measuring comprehension ability of a reader by calculating reader ranking based on correct answer lines recorded by eye gaze tracker (mounted on reader's eye) and number of correct answers given by reader. Time is measured to find the answer line (page time T1) and time spent on the answer line (score time T2). The ratio (T2/T1) of both these time parameters plays vital role in evaluation of rank of reader. Score is calculated only if reader reads the answer line/s and after that gives the correct answer otherwise the score will be zero for same question. Finally, the reader gets score and rank among the existing readers on the basis of time ratio and correctness of answers. |
Nicholas D. Smith; Fiona C. Glen; Vera M. Mönter; David P. Crabb Using eye tracking to assess reading performance in patients with glaucoma: A within-person study Journal Article In: Journal of Ophthalmology, vol. 2014, pp. 1–10, 2014. @article{Smith2014, Reading is often cited as a demanding task for patients with glaucomatous visual field (VF) loss, yet reading speed varies widely between patients and does not appear to be predicted by standard visual function measures. This within-person study aimed to investigate reading duration and eye movements when reading short passages of text in a patient's worse eye (most VF damage) when compared to their better eye (least VF damage). Reading duration and saccade rate were significantly different on average in the worse eye when compared to the better eye (P < 0.001) in 14 patients with glaucoma that had median (interquartile range) between-eye difference in mean deviation (MD; a standard clinical measure for VF loss) of 9.8 (8.3 to 14.8) dB; differences were not related to the size of the difference in MD between eyes. Patients with a more pronounced effect of longer reading duration on their worse eye made a larger proportion of "regressions" (backward saccades) and "unknown" EMs (not adhering to expected reading patterns) when reading with the worse eye when compared to the better eye. A between-eye study in patients with asymmetric disease, coupled with eye tracking, provides a useful experimental design for exploring reading performance in glaucoma. |
Beth A. Stankevich; Joy J. Geng Reward associations and spatial probabilities produce additive effects on attentional selection Journal Article In: Attention, Perception, & Psychophysics, vol. 76, no. 8, pp. 2315–2325, 2014. @article{Stankevich2014, Recent studies have shown that reward history acts as a powerful attentional bias, even overcoming top-down goals. This has led to the suggestion that rewards belong to a class of attentional cues based on selection history, which are defined by past outcomes with a stimulus feature. Selection history is thought to be separate from traditional attentional cues based on physical salience and voluntary goals, but there is relatively little understanding of how selection history operates as a mechanism of attentional selection. Critically, it has yet to be understood how multiple sources of selection history interact when presented simultaneously. For example, it may be easier to find something we like if it also appears in a predictable location. We therefore pitted spatial probabilities against reward associations and found that the two sources of information had independent and additive effects. Additionally, the strength of the two sources in biasing attentional selection could be equated. In contrast, while a nonpredictive but perceptually salient cue also exhibited independent and additive effects with reward, reward associations dominated the perceptually salient cue at all levels. Our data indicate that reward associations are part of a class of particularly potent attentional cues that guide behavior through learned expectations. However, selection history should not be thought of as a unitary concept but should be understood as a collection of independent sources of information that bias attention in a similar fashion. |
Maria Staudte; Matthew W. Crocker; Alexis Heloir; Michael Kipp The influence of speaker gaze on listener comprehension: Contrasting visual versus intentional accounts Journal Article In: Cognition, vol. 133, no. 1, pp. 317–328, 2014. @article{Staudte2014, Previous research has shown that listeners follow speaker gaze to mentioned objects in a shared environment to ground referring expressions, both for human and robot speakers. What is less clear is whether the benefit of speaker gaze is due to the inference of referen- tial intentions (Staudte and Crocker, 2011) or simply the (reflexive) shifts in visual atten- tion. That is, is gaze special in how it affects simultaneous utterance comprehension? In four eye-tracking studies we directly contrast speech-aligned speaker gaze of a virtual agent with a non-gaze visual cue (arrow). Our findings show that both cues similarly direct listeners' attention and that listeners can benefit in utterance comprehension from both cues. Only when they are similarly precise, however, does this equality extend to incongru- ent cueing sequences: that is, even when the cue sequence does not match the concurrent sequence of spoken referents can listeners benefit from gaze as well as arrows. The results suggest that listeners are able to learn a counter-predictive mapping of both cues to the sequence of referents. Thus, gaze and arrows can in principle be applied with equal flexi- bility and efficiency during language comprehension. |
Nicholas A. Steinmetz; Tirin Moore Eye movement preparation modulates neuronal responses in area V4 when dissociated from attentional demands Journal Article In: Neuron, vol. 83, no. 2, pp. 496–506, 2014. @article{Steinmetz2014, We examined whether the preparation of saccadic eye movements, when behaviorally dissociated from covert attention, modulates activity within visual cortex. We measured single-neuron and local field potential (LFP) responses to visual stimuli in area V4 while monkeys covertly attended a stimulus at one location and prepared saccades to a potential target at another. In spite of the irrelevance of visual information at the saccade target, visual activity at that location was modulated at least as much as, and often more than, activity at the covertly attended location. Modulations of activity at the attended and saccade target locations were qualitatively similar and included increased response magnitude, stimulus selectivity, and spiking reliability, as well as increased gamma and decreased low-frequency power of LFPs. These results demonstrate that saccade preparation is sufficient to modulate visual cortical representations and suggest that the interrelationship of oculomotor and attention-related mechanisms extends to posterior visual cortex. |
Chess Stetson; Richard A. Andersen The parietal reach region selectively anti-synchronizes with dorsal premotor cortex during planning Journal Article In: Journal of Neuroscience, vol. 34, no. 36, pp. 11948–11958, 2014. @article{Stetson2014, Recent reports have indicated that oscillations shared across distant cortical regions can enhance their connectivity, but do coherent oscillations ever diminish connectivity? We investigated oscillatory activity in two distinct reach-related regions in the awake behaving monkey (Macaca mulatta): the parietal reach region (PRR) and the dorsal premotor cortex (PMd). PRR and PMd were found to oscillate at similar frequencies (beta, 15–30 Hz) during periods of fixation and movement planning. At first glance, the stronger oscillator of the two, PRR, would seem to drive the weaker, PMd. However, a more fine-grained measure, the partial spike-field coherence, revealed a different relationship. Relative to global beta-band activity in the brain, action potentials in PRR anti-synchronize with PMd oscillations. These data suggest that, rather than driving PMd during planning, PRR neurons fire in such a way that they are less likely to communicate information to PMd. |
Caleb E. Strait; Tommy C. Blanchard; Benjamin Y. Hayden Reward value comparison via mutual inhibition in ventromedial prefrontal cortex Journal Article In: Neuron, vol. 82, no. 6, pp. 1357–1366, 2014. @article{Strait2014, Recent theories suggest that reward-based choice reflects competition between value signals in the ventromedial prefrontal cortex (vmPFC). We tested this idea by recording vmPFC neurons while macaques performed a gambling task with asynchronous offer presentation. We found that neuronal activity shows four patterns consistent with selection via mutual inhibition: (1) correlated tuning for probability and reward size, suggesting that vmPFC carries an integrated value signal; (2) anti-correlated tuning curves for the two options, suggesting mutual inhibition; (3) neurons rapidly come to signal the value of the chosen offer, suggesting the circuit serves to produce a choice; and (4) after regressing out the effects of option values, firing rates still could predict choice-a choice probability signal. In addition, neurons signaled gamble outcomes, suggesting that vmPFC contributes to both monitoring and choice processes. These data suggest a possible mechanism for reward-based choice and endorse the centrality of vmPFC in that process. |
Lars Strother; Danila Alferov Inter-element orientation and distance influence the duration of persistent contour integration Journal Article In: Frontiers in Psychology, vol. 5, pp. 1273, 2014. @article{Strother2014, Contour integration is a fundamental form of perceptual organization. We introduce a new method of studying the mechanisms responsible for contour integration. This method capitalizes on the perceptual persistence of contours under conditions of impending camouflage. Observers viewed arrays of randomly arranged line segments upon which circular contours comprised of similar line segments were superimposed via abrupt onset. Crucially, these contours remained visible for up to a few seconds following onset, but eventually disappeared due to the camouflaging effects of surrounding background line segments. Our main finding was that the duration of contour visibility depended on the distance and degree of co-alignment between adjacent contour segments such that relatively dense smooth contours persisted longest. The stimulus-related effects reported here parallel similar results from contour detection studies, and complement previous reported top-down influences on contour persistence (Strother et al., 2011). We propose that persistent contour visibility reflects the sustained activity of recurrent processing loops within and between visual cortical areas involved in contour integration and other important stages of visual object recognition. |
L. L. Tanaka; J. C. Dessing; Pankhuri Malik; S. L. Prime; J. Douglas Crawford The effects of TMS over dorsolateral prefrontal cortex on trans-saccadic memory of multiple objects Journal Article In: Neuropsychologia, vol. 63, pp. 185–193, 2014. @article{Tanaka2014, Humans typically make several rapid eye movements (saccades) per second. It is thought that visual working memory can retain and spatially integrate three to four objects or features across each saccade but little is known about this neural mechanism. Previously we showed that transcranial magnetic stimulation (TMS) to the posterior parietal cortex and frontal eye fields degrade trans-saccadic memory of multiple object features (Prime, Vesia, & Crawford, 2008, Journal of Neuroscience, 28(27), 6938-6949; Prime, Vesia, & Crawford, 2010, Cerebral Cortex, 20(4), 759-772.). Here, we used a similar protocol to investigate whether dorsolateral prefrontal cortex (DLPFC), an area involved in spatial working memory, is also involved in trans-saccadic memory. Subjects were required to report changes in stimulus orientation with (saccade task) or without (fixation task) an eye movement in the intervening memory interval. We applied single-pulse TMS to left and right DLPFC during the memory delay, timed at three intervals to arrive approximately 100. ms before, 100. ms after, or at saccade onset. In the fixation task, left DLPFC TMS produced inconsistent results, whereas right DLPFC TMS disrupted performance at all three intervals (significantly for presaccadic TMS). In contrast, in the saccade task, TMS consistently facilitated performance (significantly for left DLPFC/. perisaccadic TMS and right DLPFC/. postsaccadic TMS) suggesting a dis-inhibition of trans-saccadic processing. These results are consistent with a neural circuit of trans-saccadic memory that overlaps and interacts with, but is partially separate from the circuit for visual working memory during sustained fixation. |
Krzysztof Templin; Piotr Didyk; Karol Myszkowski; Mohamed M Hefeeda; Hans-Peter Seidel; Wojciech Matusik Modeling and optimizing eye vergence response to stereoscopic cuts Journal Article In: ACM Transactions on Graphics, vol. 33, no. 4, pp. 1–8, 2014. @article{Templin2014, Sudden temporal depth changes, such as cuts that are introduced by video edits, can significantly degrade the quality of stereoscopic content. Since usually not encountered in the real world, they are very challenging for the audience. This is because the eye vergence has to constantly adapt to new disparities in spite of conflicting accommodation requirements. Such rapid disparity changes may lead to confusion, reduced understanding of the scene, and overall attractiveness of the content. In most cases the problem cannot be solved by simply matching the depth around the transition, as this would require flattening the scene completely. To better understand this limitation of the human visual system, we conducted a series of eye-tracking experiments. The data obtained allowed us to derive and evaluate a model describing adaptation of vergence to disparity changes on a stereoscopic display. Besides computing user-specific models, we also estimated parameters of an average observer model. This enables a range of strategies for minimizing the adaptation time in the audience. |
Antonia F. Ten Brink; Tanja C. W. Nijboer; Nathan Van der Stoep; Stefan Van der Stigchel The influence of vertically and horizontally aligned visual distractors on aurally guided saccadic eye movements Journal Article In: Experimental Brain Research, vol. 232, no. 4, pp. 1357–1366, 2014. @article{TenBrink2014, Eye movements towards a new target can be guided or disrupted by input from multiple modalities. The degree of oculomotor competition evoked by a distractor depends on both distractor and target properties, such as distractor salience or certainty regarding the target location. The ability to localize the target is particularly important when studying saccades made towards auditory targets, since determination of elevation and azimuth of a sound are based on different processes, and these processes may be affected independently by a distractor. We investigated the effects of a visual distractor on saccadic eye movements made to an auditory target in a two-dimensional plane. Results showed that the competition evoked by a vertical visual distractor was stronger compared with a horizontal visual distractor. The eye movements that were not captured by the vertical visual distractor were still influenced by it: a deviation of endpoints was seen in the direction of the visual distractor. Furthermore, the interference evoked by a high-contrast visual distractor was stronger compared with low-contrast visual stimuli, which was reflected by a faster initiation of an eye movement towards the high-contrast visual distractor and a stronger shift of endpoints in the direction of the high-contrast visual distractor. Together, these findings show that the influence of a visual distractor on aurally guided eye movements depends strongly on its location relative to the target, and to a lesser extent, on stimulus contrast. |
Hong-Yue Sun; Li-Lin Rao; Kun Zhou; Shu Li Formulating an emergency plan based on expectation-maximization is one thing, but applying it to a single case is another Journal Article In: Journal of Risk Research, vol. 17, no. 7, pp. 785–814, 2014. @article{Sun2014, This research extends the exploration of single-play/multiple-play distinctions from monetary gambling paradigm to emergency management situation. We conducted three studies (two survey studies and one eye tracking study) to test whether an emergency plan we formulated in advance based on expectation-maximization would be likely to be applied in a single case. In the first two survey studies we found that the plan with the higher EV was more likely to be preferred when the plan was applied 100 times or to 100 areas than when the plan was applied only once or to only one area. We also found significant framing and reflection effects, both of which violated the invariance principle in the single-application condition, but not in the multiple-application condition. Furthermore, in the eye tracking study, we found distinctly different eye movement patterns in the single-application condition and the multiple-application condition. The eye movement patterns in the multiple-application condition are more consistent with the predictions deduced from expectation computation. The overall results suggest that a gap exists between the formulation and the implementation of an emergency plan. Formulating an emergency plan based on expectation-maximization is doable, but applying it to a single case may be more challenging. |
Benjamin Swets; Matthew E. Jacovina; Richard J. Gerrig Individual differences in the scope of speech planning: Evidence from eye-movements Journal Article In: Language and Cognition, vol. 6, no. 1, pp. 12–44, 2014. @article{Swets2014, Previous research has demonstrated that the scope of speakers' planning in language production varies in response to external forces such as time pressure. This susceptibility to external pressures indicates a flexibly incremental production system: speakers plan utterances piece by piece, but external pressures affect the size of the pieces speakers buffer. In the current study, we explore internal constraints on speech planning. Specifi cally, we examine whether individual differences in working memory predict the scope and efficiency of advance planning. In our task, speakers described picture arrays to partners in a matching game. The arrays sometimes required speakers to note a contrast between a sentence-initial object (e.g., a four-legged cat) and a sentence-final object (e.g., a three-legged cat). Based on prior screening, we selected participants who differed on verbal working memory span. Eye-movement measures revealed that high-span speakers were more likely to gaze at the contrasting pictures prior to articulation than were low-span speakers. As a result, high-span speakers were also more likely to reference the contrast early in speech. We conclude that working memory plays a substantial role in the fl exibility of incremental speech planning. |
Sarit F. A. Szpiro; Miriam Spering; Marisa Carrasco Perceptual learning modifies untrained pursuit eye movements Journal Article In: Journal of Vision, vol. 14, no. 8, pp. 1–13, 2014. @article{Szpiro2014, Perceptual learning improves detection and discrimination of relevant visual information in mature humans, revealing sensory plasticity. Whether visual perceptual learning affects motor responses is unknown. Here we implemented a protocol that enabled us to address this question. We tested a perceptual response (motion direction estimation, in which observers overestimate motion direction away from a reference) and a motor response (voluntary smooth pursuit eye movements). Perceptual training led to greater overestimation and, remarkably, it modified untrained smooth pursuit. In contrast, pursuit training did not affect overestimation in either pursuit or perception, even though observers in both training groups were exposed to the same stimuli for the same time period. A second experiment revealed that estimation training also improved discrimination, indicating that overestimation may optimize perceptual sensitivity. Hence, active perceptual training is necessary to alter perceptual responses, and an acquired change in perception suffices to modify pursuit, a motor response. |
Bahareh Taghizadeh; Alexander Gail Spatial task context makes short-latency reaches prone to induced Roelofs illusion Journal Article In: Frontiers in Human Neuroscience, vol. 8, pp. 673, 2014. @article{Taghizadeh2014, The perceptual localization of an object is often more prone to illusions than an immediate visuomotor action towards that object. The induced Roelofs effect (IRE) probes the illusory influence of task-irrelevant visual contextual stimuli on the processing of task-relevant visuospatial instructions during movement preparation. In the IRE, the position of a task-irrelevant visual object induces a shift in the localization of a visual target when subjects indicate the position of the target by verbal response, key-presses or delayed pointing to the target ("perception" tasks), but not when immediately pointing or reaching towards it without instructed delay ("action" tasks). This discrepancy was taken as evidence for the dual-visual-stream or perception-action hypothesis, but was later explained by a phasic distortion of the egocentric spatial reference frame which is centered on subjective straight-ahead (SSA) and used for reach planning. Both explanations critically depend on delayed movements to explain the IRE for action tasks. Here we ask: first, if the IRE can be observed for short-latency reaches; second, if the IRE in fact depends on a distorted egocentric frame of reference. Human subjects were tested in new versions of the IRE task in which the reach goal had to be localized with respect to another object, i.e., in an allocentric reference frame. First, we found an IRE even for immediate reaches in our allocentric task, but not for an otherwise similar egocentric control task. Second, the IRE depended on the position of the task-irrelevant frame relative to the reference object, not relative to SSA. We conclude that the IRE for reaching does not mandatorily depend on prolonged response delays, nor does it depend on motor planning in an egocentric reference frame. Instead, allocentric encoding of a movement goal is sufficient to make immediate reaches susceptible to IRE, underlining the context dependence of visuomotor illusions. |
Annie Tremblay; Elsa Spinelli English listeners' use of distributional and acoustic-phonetic cues to liaison in French: Evidence from eye movements Journal Article In: Language and Speech, vol. 57, no. 3, pp. 310–337, 2014. @article{Tremblay2014, This study investigates English listeners' use of distributional and acoustic-phonetic cues to liaison in French. Liaison creates a misalignment of the syllable and word boundaries, but is signaled by distributional cues (/z/ is a frequent liaison but not a frequent word onset; /t/ is a frequent word onset but a less frequent liaison) and acoustic-phonetic cues (liaison consonants are 15 per cent shorter than word-initial consonants). English-speaking French learners completed a visual- world eye-tracking experiment in which they heard adjective-noun sequences where the pivotal consonant was /t/ (expected advantage for consonant-initial words) or /z/ (expected advantage for liaison-initial words). Their results were compared to those of native French speakers. Both groups showed an advantage for consonant-initial targets with /t/ but no advantage for consonant- or liaison-initial targets with /z/. Both groups' competitor fixations were modulated by the duration of the pivotal consonant, but only the learners' fixations to liaison-initial targets were modulated by the duration of the pivotal consonant. This suggests that English listeners use both top-down (distributional) and bottom-up (acoustic-phonetic) cues to liaison in French. Their greater reliance on acoustic-phonetic cues is hypothesized to stem in part from English, where such cues play an important role for locating word boundaries. |