EyeLink Eye-Tracker Publications / Research Papers

All 7000+ peer-reviewed EyeLink eye tracking publications (up to 2018) are listed below in alphabetical order based on the first author. You can search the publications library using key words such as Visual Search, Smooth Pursuit, Parkinsons, etc. You can also search for individual author names. Eye tracking studies grouped by research area can be found on the solutions pages. If we missed any EyeLink eye tracking paper, please email us!

7170 entries « ‹ 1 of 72 › »

David Aagten-Murphy; Paul M Bays

Automatic and intentional influences on saccade landing Journal Article

Journal of Neurophysiology, 118 , pp. 1105–1122, 2017.

Abstract | Links | BibTeX

@article{Aagten-Murphy2017,
title = {Automatic and intentional influences on saccade landing},
author = {David Aagten-Murphy and Paul M Bays},
doi = {10.1152/jn.00141.2017},
year = {2017},
date = {2017-01-01},
journal = {Journal of Neurophysiology},
volume = {118},
pages = {1105--1122},
abstract = {Saccadic eye movements enable us to rapidly direct our high-resolution fovea onto relevant parts of the visual world. However, while we can intentionally select a location as a saccade target, the wider visual scene also influences our executed movements. In the presence of multiple objects, eye movements may be “captured” to the location of a distractor object, or be biased toward the intermediate position between objects (the “global effect”). Here we examined how the relative strengths of the global effect and visual object capture changed with saccade latency, the separation between visual items and stimulus contrast. Importantly, while many previous studies have omitted giving observers explicit instructions, we instructed participants to either saccade to a specified target object or to the midpoint between two stimuli. This allowed us to examine how their explicit movement goal influenced the likelihood that their saccades terminated at either the target, distractor, or intermediate locations. Using a probabilistic mixture model, we found evidence that both visual object capture and the global effect co-occurred at short latencies and declined as latency increased. As object separation increased, capture came to dominate the landing positions of fast saccades, with reduced global effect. Using the mixture model fits, we dissociated the proportion of unavoidably captured saccades to each location from those intentionally directed to the task goal. From this we could extract the time course of competition between automatic capture and intentional targeting. We show that task instructions substantially altered the distribution of saccade landing points, even at the shortest latencies. NEW & NOTEWORTHY When making an eye movement to a target location, the presence of a nearby distractor can cause the saccade to unintentionally terminate at the distractor itself or the average position in between stimuli. With probabilistic mixture models, we quantified how both unavoidable capture and goal-di rected targeting were influenced by changing the task and the target-distractor separation. Using this novel technique, we could extract the time course over which automatic and intentional processes compete for control of saccades.},
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Saccadic eye movements enable us to rapidly direct our high-resolution fovea onto relevant parts of the visual world. However, while we can intentionally select a location as a saccade target, the wider visual scene also influences our executed movements. In the presence of multiple objects, eye movements may be “captured” to the location of a distractor object, or be biased toward the intermediate position between objects (the “global effect”). Here we examined how the relative strengths of the global effect and visual object capture changed with saccade latency, the separation between visual items and stimulus contrast. Importantly, while many previous studies have omitted giving observers explicit instructions, we instructed participants to either saccade to a specified target object or to the midpoint between two stimuli. This allowed us to examine how their explicit movement goal influenced the likelihood that their saccades terminated at either the target, distractor, or intermediate locations. Using a probabilistic mixture model, we found evidence that both visual object capture and the global effect co-occurred at short latencies and declined as latency increased. As object separation increased, capture came to dominate the landing positions of fast saccades, with reduced global effect. Using the mixture model fits, we dissociated the proportion of unavoidably captured saccades to each location from those intentionally directed to the task goal. From this we could extract the time course of competition between automatic capture and intentional targeting. We show that task instructions substantially altered the distribution of saccade landing points, even at the shortest latencies. NEW & NOTEWORTHY When making an eye movement to a target location, the presence of a nearby distractor can cause the saccade to unintentionally terminate at the distractor itself or the average position in between stimuli. With probabilistic mixture models, we quantified how both unavoidable capture and goal-di rected targeting were influenced by changing the task and the target-distractor separation. Using this novel technique, we could extract the time course over which automatic and intentional processes compete for control of saccades.

Rasmus Aamand; Thomas Dalsgaard; Yi-Ching Lynn Ho; Arne Møller; Andreas Roepstorff; Torben E Lund

A NO way to BOLD?: Dietary nitrate alters the hemodynamic response to visual stimulation Journal Article

NeuroImage, 83 , pp. 397–407, 2013.

Abstract | Links | BibTeX

@article{Aamand2013,
title = {A NO way to BOLD?: Dietary nitrate alters the hemodynamic response to visual stimulation},
author = {Rasmus Aamand and Thomas Dalsgaard and Yi-Ching Lynn Ho and Arne Møller and Andreas Roepstorff and Torben E Lund},
doi = {10.1016/j.neuroimage.2013.06.069},
year = {2013},
date = {2013-01-01},
journal = {NeuroImage},
volume = {83},
pages = {397--407},
publisher = {Elsevier Inc.},
abstract = {Neurovascular coupling links neuronal activity to vasodilation. Nitric oxide (NO) is a potent vasodilator, and in neurovascular coupling NO production from NO synthases plays an important role. However, another pathway for NO production also exists, namely the nitrate-nitrite-NO pathway. On this basis, we hypothesized that dietary nitrate (NO3-) could influence the brain's hemodynamic response to neuronal stimulation. In the present study, 20 healthy male participants were given either sodium nitrate (NaNO3) or sodium chloride (NaCl) (saline placebo) in a crossover study and were shown visual stimuli based on the retinotopic characteristics of the visual cortex. Our primary measure of the hemodynamic response was the blood oxygenation level dependent (BOLD) response measured with high-resolution functional magnetic resonance imaging (0.64×0.64×1.8mm) in the visual cortex. From this response, we made a direct estimate of key parameters characterizing the shape of the BOLD response (i.e. lag and amplitude). During elevated nitrate intake, corresponding to the nitrate content of a large plate of salad, both the hemodynamic lag and the BOLD amplitude decreased significantly (7.0±2% and 7.9±4%, respectively), and the variation across activated voxels of both measures decreased (12.3±4% and 15.3±7%, respectively). The baseline cerebral blood flow was not affected by nitrate. Ourexperiments demonstrate, for the first time, that dietary nitrate may modulate the local cerebral hemodynamic response to stimuli. A faster and smaller BOLD response, with less variation across local cortex, is consistent with an enhanced hemodynamic coupling during elevated nitrate intake. These findings suggest that dietary patterns, via the nitrate-nitrite-NO pathway, may be a potential way to affect key properties of neurovascular coupling. This could have major clinical implications, which remain to be explored.},
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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

Journal of Applied Physiology, 116 (3), pp. 267–273, 2014.

Abstract | Links | BibTeX

@article{Aamand2014,
title = {Dietary nitrate facilitates an acetazolamide-induced increase in cerebral blood flow during visual stimulation},
author = {Rasmus Aamand and Yi-Ching Lynn Ho and Thomas Dalsgaard and Andreas Roepstorff and Torben E Lund},
doi = {10.1152/japplphysiol.00797.2013},
year = {2014},
date = {2014-01-01},
journal = {Journal of Applied Physiology},
volume = {116},
number = {3},
pages = {267--273},
abstract = {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.},
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Matthew J Abbott; Bernhard Angele; Danbi Y Ahn; Keith Rayner

Skipping syntactically illegal the previews: The role of predictability Journal Article

Journal of Experimental Psychology: Learning, Memory, and Cognition, 41 (6), pp. 1703–1714, 2015.

Abstract | Links | BibTeX

Matthew J Abbott; Adrian Staub

The effect of plausibility on eye movements in reading: Testing E-Z Reader's null predictions Journal Article

Journal of Memory and Language, 85 , pp. 76–87, 2015.

Abstract | Links | BibTeX

Parisa Abedi Khoozani; Gunnar Blohm

Neck muscle spindle noise biases reaches in a multisensory integration task Journal Article

Journal of Neurophysiology, 120 (3), pp. 893–909, 2018.

Abstract | Links | BibTeX

@article{AbediKhoozani2018,
title = {Neck muscle spindle noise biases reaches in a multisensory integration task},
author = {Parisa {Abedi Khoozani} and Gunnar Blohm},
doi = {10.1152/jn.00643.2017},
year = {2018},
date = {2018-01-01},
journal = {Journal of Neurophysiology},
volume = {120},
number = {3},
pages = {893--909},
abstract = {Reference frame Transformations (RFTs) are crucial components of sensorimotor transformations in the brain. Stochasticity in RFTs has been suggested to add noise to the transformed signal due to variability in transformation parameter estimates (e.g. angle) as well as the stochastic nature of computations in spiking networks of neurons. Here, we varied the RFT angle together with the associated variability and evaluated the behavioral impact in a reaching task that required variability-dependent visual-proprioceptive multi-sensory integration. Crucially, reaches were performed with the head either straight or rolled 30deg to either shoulder and we also applied neck loads of 0 or 1.8kg (left or right) in a 3x3 design, resulting in different combinations of estimated head roll angle magnitude and variance required in RFTs. A novel 3D stochastic model of multi-sensory integration across reference frames was fitted to the data and captured our main behavioral findings: (1) neck load biased head angle estimation across all head roll orientations resulting in systematic shifts in reach errors; (2) Increased neck muscle tone led to increased reach variability, due to signal-dependent noise; (3) both head roll and neck load created larger angular errors in reaches to visual targets away from the body compared to reaches toward the body. These results show that noise in muscle spindles and stochasticity in general have a tangible effect on RFTs underlying reach planning. Since RFTs are omnipresent in the brain, our results could have implication for processes as diverse as motor control, decision making, posture / balance control, and perception.},
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Mathias Abegg; Hyung Lee; Jason J S Barton

Systematic diagonal and vertical errors in antisaccades and memory-guided saccades Journal Article

Journal of Eye Movement Research, 3 (3), pp. 1–10, 2010.

Abstract | BibTeX

Mathias Abegg; Amadeo R Rodriguez; Hyung Lee; Jason J S Barton

‘Alternate-goal bias' in antisaccades and the inXuence of expectation Journal Article

Experimental Brain Research, 203 (3), pp. 553–562, 2010.

Abstract | Links | BibTeX

Mathias Abegg; Dara S Manoach; Jason J S Barton

Knowing the future: Partial foreknowledge effects on the programming of prosaccades and antisaccades Journal Article

Vision Research, 51 (1), pp. 215–221, 2011.

Abstract | Links | BibTeX

Mathias Abegg; Nishant Sharma; Jason J S Barton

Antisaccades generate two types of saccadic inhibition Journal Article

Biological Psychology, 89 (1), pp. 191–194, 2012.

Abstract | Links | BibTeX

Mathias Abegg; Dario Pianezzi; Jason J S Barton

A vertical asymmetry in saccades Journal Article

Journal of Eye Movement Research, 8 (5), pp. 1–10, 2015.

Abstract | Links | BibTeX

Naotoshi Abekawa; H Gomi

Spatial coincidence of intentional actions modulates an implicit visuomotor control Journal Article

Journal of Neurophysiology, 103 (5), pp. 2717–2727, 2010.

Abstract | Links | BibTeX

@article{Abekawa2010,
title = {Spatial coincidence of intentional actions modulates an implicit visuomotor control},
author = {Naotoshi Abekawa and H Gomi},
doi = {10.1152/jn.91133.2008},
year = {2010},
date = {2010-01-01},
journal = {Journal of Neurophysiology},
volume = {103},
number = {5},
pages = {2717--2727},
abstract = {We investigated a visuomotor mechanism contributing to reach correction: the manual following response (MFR), which is a quick response to background visual motion that frequently occurs as a reafference when the body moves. Although several visual specificities of the MFR have been elucidated, the functional and computational mechanisms of its motor coordination remain unclear mainly because it involves complex relationships among gaze, reaching target, and visual stimuli. To directly explore how these factors interact in the MFR, we assessed the impact of spatial coincidences among gaze, arm reaching, and visual motion on the MFR. When gaze location was displaced from the reaching target with an identical visual motion kept on the retina, the amplitude of the MFR significantly decreased as displacement increased. A factorial manipulation of gaze, reaching-target, and visual motion locations showed that the response decrease is due to the spatial separation between gaze and reaching target but is not due to the spatial separation between visual motion and reaching target. Additionally, elimination of visual motion around the fovea attenuated the MFR. The effects of these spatial coincidences on the MFR are completely different from their effects on the perceptual mislocalization of targets caused by visual motion. Furthermore, we found clear differences between the modulation sensitivities of the MFR and the ocular following response to spatial mismatch between gaze and reaching locations. These results suggest that the MFR modulation observed in our experiment is not due to changes in visual interaction between target and visual motion or to modulation of motion sensitivity in early visual processing. Instead the motor command of the MFR appears to be modulated by the spatial relationship between gaze and reaching.},
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Naotoshi Abekawa; Toshio Inui; Hiroaki Gomi

Eye-hand coordination in on-line visuomotor adjustments Journal Article

NeuroReport, 25 (7), pp. 441–445, 2014.

Abstract | Links | BibTeX

Naotoshi Abekawa; Hiroaki Gomi

Online gain update for manual following response accompanied by gaze shift during arm reaching Journal Article

Journal of Neurophysiology, 113 (4), pp. 1206–1216, 2015.

Abstract | Links | BibTeX

@article{Abekawa2015,
title = {Online gain update for manual following response accompanied by gaze shift during arm reaching},
author = {Naotoshi Abekawa and Hiroaki Gomi},
doi = {10.1152/jn.00281.2014},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurophysiology},
volume = {113},
number = {4},
pages = {1206--1216},
abstract = {To capture objects by hand, online motor corrections are required to compensate for self-body movements. Recent studies have shown that background visual motion, usually caused by body movement, plays a significant role in such online corrections. Visual motion applied during a reaching movement induces a rapid and automatic manual following response (MFR) in the direction of the visual motion. Importantly, the MFR amplitude is modulated by the gaze direction relative to the reach target location (i.e., foveal or peripheral reaching). That is, the brain specifies the adequate visuomotor gain for an online controller based on gaze-reach coordination. However, the time or state point at which the brain specifies this visuomotor gain remains unclear. More specifically, does the gain change occur even during the execution of reaching? In the present study, we measured MFR amplitudes during a task in which the participant performed a saccadic eye movement that altered the gaze-reach coordination during reaching. The results indicate that the MFR amplitude immediately after the saccade termination changed according to the new gaze-reach coordination, suggesting a flexible online updating of the MFR gain during reaching. An additional experiment showed that this gain updating mostly started before the saccade terminated. Therefore, the MFR gain updating process would be triggered by an ocular command related to saccade planning or execution based on forthcoming changes in the gaze-reach coordination. Our findings suggest that the brain flexibly updates the visuomotor gain for an online controller even during reaching movements based on continuous monitoring of the gaze-reach coordination.},
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Naotoshi Abekawa; Elisa R Ferre; Maria Gallagher; Hiroaki Gomi; Patrick Haggard

Disentangling the visual, motor and representational effects of vestibular input Journal Article

Cortex, 104 , pp. 46–57, 2018.

Abstract | Links | BibTeX

Larry Allen Abel; Zhong I Wang; Louis F Dell'Osso

Wavelet analysis in infantile nystagmus syndrome: Limitations and abilities Journal Article

Investigative Ophthalmology & Visual Science, 49 (8), pp. 3413–3423, 2008.

Abstract | Links | BibTeX

Dekel Abeles; Shlomit Yuval-Greenberg

Just look away: Gaze aversions as an overt attentional disengagement mechanism Journal Article

Cognition, 168 , pp. 99–109, 2017.

Abstract | Links | BibTeX

Dekel Abeles; Roy Amit; Shlomit Yuval-Greenberg

Oculomotor behavior during non-visual tasks: The role of visual saliency Journal Article

PLoS ONE, 13 (6), pp. 1–21, 2018.

Abstract | Links | BibTeX

Irene Ablinger; Walter Huber; Kerstin I Schattka; Ralph Radach

Recovery in a letter-by-letter reader: More efficiency at the expense of normal reading strategy Journal Article

Neurocase, 19 (3), pp. 236–255, 2013.

Abstract | Links | BibTeX

Irene Ablinger; Walter Huber; Ralph Radach

Eye movement analyses indicate the underlying reading strategy in the recovery of lexical readers Journal Article

Aphasiology, 28 (6), pp. 640–657, 2014.

Abstract | Links | BibTeX

@article{Ablinger2014,
title = {Eye movement analyses indicate the underlying reading strategy in the recovery of lexical readers},
author = {Irene Ablinger and Walter Huber and Ralph Radach},
doi = {10.1080/02687038.2014.894960},
year = {2014},
date = {2014-01-01},
journal = {Aphasiology},
volume = {28},
number = {6},
pages = {640--657},
abstract = {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.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

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 Von 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

Neuropsychological Rehabilitation, 24 (6), pp. 833–867, 2014.

Abstract | Links | BibTeX

Irene Ablinger; Ralph Radach

Diverging receptive and expressive word processing mechanisms in a deep dyslexic reader Journal Article

Neuropsychologia, 81 , pp. 12–21, 2016.

Abstract | Links | BibTeX

@article{Ablinger2016,
title = {Diverging receptive and expressive word processing mechanisms in a deep dyslexic reader},
author = {Irene Ablinger and Ralph Radach},
doi = {10.1016/j.neuropsychologia.2015.11.023},
year = {2016},
date = {2016-01-01},
journal = {Neuropsychologia},
volume = {81},
pages = {12--21},
publisher = {Elsevier},
abstract = {We report on KJ, a patient with acquired dyslexia due to cerebral artery infarction. He represents an unusually clear case of an "output" deep dyslexic reader, with a distinct pattern of pure semantic reading. According to current neuropsychological models of reading, the severity of this condition is directly related to the degree of impairment in semantic and phonological representations and the resulting imbalance in the interaction between the two word processing pathways. The present work sought to examine whether an innovative eye movement supported intervention combining lexical and segmental therapy would strengthen phonological processing and lead to an attenuation of the extreme semantic over-involvement in KJ's word identification process. Reading performance was assessed before (T1) between (T2) and after (T3) therapy using both analyses of linguistic errors and word viewing patterns. Therapy resulted in improved reading aloud accuracy along with a change in error distribution that suggested a return to more sequential reading. Interestingly, this was in contrast to the dynamics of moment-to-moment word processing, as eye movement analyses still suggested a predominantly holistic strategy, even at T3. So, in addition to documenting the success of the therapeutic intervention, our results call for a theoretically important conclusion: Real-time letter and word recognition routines should be considered separately from properties of the verbal output. Combining both perspectives may provide a promising strategy for future assessment and therapy evaluation.},
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}

Elger L Abrahamse; Wout Duthoo; Wim Notebaert; Evan F Risko

Attention modulation by proportion congruency: The asymmetrical list shifting effect Journal Article

Journal of Experimental Psychology: Learning, Memory, and Cognition, 39 (5), pp. 1552–1562, 2013.

Abstract | BibTeX

Arman Abrahamyan; Laura Luz Silva; Steven C Dakin; Matteo Carandini; Justin L Gardner

Adaptable history biases in human perceptual decisions Journal Article

Proceedings of the National Academy of Sciences, 113 (25), pp. E3548–E3557, 2016.

Abstract | Links | BibTeX

Joana Acha; Manuel Perea

The effect of neighborhood frequency in reading: Evidence with transposed-letter neighbors Journal Article

Cognition, 108 , pp. 290–300, 2008.

Abstract | BibTeX

Alper Açik; Selim Onat; Frank Schumann; Wolfgang Einhäuser; Peter König

Effects of luminance contrast and its modifications on fixation behavior during free viewing of images from different categories Journal Article

Vision Research, 49 (12), pp. 1541–1553, 2009.

Abstract | Links | BibTeX

Alper Açik; Adjmal Sarwary; Rafael Schultze-Kraft; Selim Onat; Peter König

Developmental changes in natural viewing behavior: Bottom-up and top-down differences between children, young adults and older adults Journal Article

Frontiers in Psychology, 1 , pp. 1–14, 2010.

Abstract | Links | BibTeX

@article{Acik2010,
title = {Developmental changes in natural viewing behavior: Bottom-up and top-down differences between children, young adults and older adults},
author = {Alper A{ç}ik and Adjmal Sarwary and Rafael Schultze-Kraft and Selim Onat and Peter König},
doi = {10.3389/fpsyg.2010.00207},
year = {2010},
date = {2010-01-01},
journal = {Frontiers in Psychology},
volume = {1},
pages = {1--14},
publisher = {10},
address = {doi},
abstract = {Despite the growing interest in fixation selection under natural conditions, there is a major gap in the literature concerning its developmental aspects. Early in life, bottom-up processes, such as local image feature - color, luminance contrast etc. - guided viewing, might be prominent but later overshadowed by more top-down processing. Moreover, with decline in visual functioning in old age, bottom-up processing is known to suffer. Here we recorded eye movements of 7- to 9-year-old children, 19- to 27-year-old adults, and older adults above 72 years of age while they viewed natural and complex images before performing a patch-recognition task. Task performance displayed the classical inverted U-shape, with young adults outperforming the other age groups. Fixation discrimination performance of local feature values dropped with age. Whereas children displayed the highest feature values at fixated points, suggesting a bottom-up mechanism, older adult viewing behavior was less feature-dependent, reminiscent of a top-down strategy. Importantly, we observed a double dissociation between children and elderly regarding the effects of active viewing on feature-related viewing: Explorativeness correlated with feature-related viewing negatively in young age, and positively in older adults. The results indicate that, with age, bottom-up fixation selection loses strength and/or the role of top-down processes becomes more important. Older adults who increase their feature-related viewing by being more explorative make use of this low-level information and perform better in the task. The present study thus reveals an important developmental change in natural and task-guided viewing.},
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Alper Acik; Andreas Bartel; Peter Konig

Real and implied motion at the center of gaze Journal Article

Journal of Vision, 14 (1), pp. 1–19, 2014.

Abstract | Links | BibTeX

Leah Acker; Erica N Pino; Edward S Boyden; Robert Desimone

FEF inactivation with improved optogenetic methods Journal Article

Proceedings of the National Academy of Sciences, 113 (46), pp. E7297–E7306, 2016.

Abstract | Links | BibTeX

John F Ackermann; Michael S Landy

Choice of saccade endpoint under risk Journal Article

Journal of Vision, 13 (3), pp. 1–20, 2013.

Abstract | Links | BibTeX

@article{Ackermann2013,
title = {Choice of saccade endpoint under risk},
author = {John F Ackermann and Michael S Landy},
doi = {10.1167/13.3.27},
year = {2013},
date = {2013-01-01},
journal = {Journal of Vision},
volume = {13},
number = {3},
pages = {1--20},
abstract = {Eye movements function to bring detailed information onto the high-resolution region of the retina. Previous research has shown that human observers select fixation points that maximize information acquisition and minimize target location uncertainty. In this study, we ask whether human observers choose the saccade endpoint that maximizes gain when there are explicit rewards associated with correctly detecting the target. Observers performed an 8-alternative forced-choice detection task for a contrast-defined target in noise. After a single saccade, observers indicated the target location. Each potential target location had an associated reward that was known to the observer. In some conditions, the reward at one location was higher than at the other locations. We compared human saccade endpoints to those of an ideal observer that maximizes expected gain given the respective human observer's visibility map, i.e., d' for target detection as a function of retinal location. Varying the location of the highest reward had a significant effect on human observers' distribution of saccade endpoints. Both human and ideal observers show a high density of saccades made toward the highest rewarded and actual target locations. But humans' overall spatial distributions of saccade endpoints differed significantly from the ideal observer as they made a greater number of saccade to locations far from the highest rewarded and actual target locations. Suboptimal choice of saccade endpoint, possibly in combination with suboptimal integration of information across saccades, had a significant effect on human observers' ability to correctly detect the target and maximize gain.},
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pubstate = {published},
tppubtype = {article}
}

John F Ackermann; M S Landy

Statistical templates for visual search Journal Article

Journal of Vision, 14 (3), pp. 1–17, 2014.

Abstract | Links | BibTeX

@article{Ackermann2014,
title = {Statistical templates for visual search},
author = {John F Ackermann and M S Landy},
doi = {10.1167/14.3.18},
year = {2014},
date = {2014-01-01},
journal = {Journal of Vision},
volume = {14},
number = {3},
pages = {1--17},
abstract = {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.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

John F Ackermann; Michael S Landy

Suboptimal decision criteria are predicted by subjectively weighted probabilities and rewards Journal Article

Attention, Perception, & Psychophysics, 77 (2), pp. 638–658, 2015.

Abstract | Links | BibTeX

David J Acunzo; John M Henderson

No emotional "Pop-out" effect in natural scene viewing Journal Article

Emotion, 11 (5), pp. 1134–1143, 2011.

Abstract | Links | BibTeX

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

Journal of Cognitive Neuroscience, 26 (10), pp. 2187–2200, 2014.

Abstract | Links | BibTeX

@article{Adab2014,
title = {Perceptual learning of simple stimuli modifies stimulus representations in posterior inferior temporal cortex},
author = {Hamed Zivari Adab and Ivo D Popivanov and Wim Vanduffel and Rufin Vogels},
doi = {10.1162/jocn},
year = {2014},
date = {2014-01-01},
journal = {Journal of Cognitive Neuroscience},
volume = {26},
number = {10},
pages = {2187--2200},
abstract = {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.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Hamed Zivari Adab; Rufin Vogels

Perturbation of posterior inferior temporal cortical activity impairs coarse orientation discrimination Journal Article

Cerebral Cortex, 26 (9), pp. 3814–3827, 2016.

Abstract | Links | BibTeX

Jos J Adam; Simona Buetti; Dirk Kerzel

Coordinated flexibility: How initial gaze position modulates eye-hand coordination and reaching Journal Article

Journal of Experimental Psychology: Human Perception and Performance, 38 (4), pp. 891–901, 2012.

Abstract | Links | BibTeX

Robert Adam; Paul M Bays; Masud Husain

Rapid decision-making under risk Journal Article

Cognitive Neuroscience, 3 (1), pp. 52–61, 2012.

Abstract | BibTeX

Robert Adam; Alexander Leff; Nihal Sinha; Christopher Turner; Paul Bays; Bogdan Draganski; Masud Husain

Dopamine reverses reward insensitivity in apathy following globus pallidus lesions Journal Article

Cortex, 49 (5), pp. 1292–1303, 2013.

Abstract | Links | BibTeX

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

Journal of Cognitive Psychology, 26 (2), pp. 166–177, 2014.

Abstract | Links | BibTeX

Rick A Adams; Eduardo Aponte; Louise Marshall; Karl J Friston

Active inference and oculomotor pursuit: The dynamic causal modelling of eye movements Journal Article

Journal of Neuroscience Methods, 242 , pp. 1–14, 2015.

Abstract | Links | BibTeX

@article{Adams2015,
title = {Active inference and oculomotor pursuit: The dynamic causal modelling of eye movements},
author = {Rick A Adams and Eduardo Aponte and Louise Marshall and Karl J Friston},
doi = {10.1016/j.jneumeth.2015.01.003},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neuroscience Methods},
volume = {242},
pages = {1--14},
publisher = {Elsevier B.V.},
abstract = {Background: This paper introduces a new paradigm that allows one to quantify the Bayesian beliefs evidenced by subjects during oculomotor pursuit. Subjects' eye tracking responses to a partially occluded sinusoidal target were recorded non-invasively and averaged. These response averages were then analysed using dynamic causal modelling (DCM). In DCM, observed responses are modelled using biologically plausible generative or forward models - usually biophysical models of neuronal activity. New method: Our key innovation is to use a generative model based on a normative (Bayes-optimal) model of active inference to model oculomotor pursuit in terms of subjects' beliefs about how visual targets move and how their oculomotor system responds. Our aim here is to establish the face validity of the approach, by manipulating the content and precision of sensory information - and examining the ensuing changes in the subjects' implicit beliefs. These beliefs are inferred from their eye movements using the normative model. Results: We show that on average, subjects respond to an increase in the 'noise' of target motion by increasing sensory precision in their models of the target trajectory. In other words, they attend more to the sensory attributes of a noisier stimulus. Conversely, subjects only change kinetic parameters in their model but not precision, in response to increased target speed. Conclusions: Using this technique one can estimate the precisions of subjects' hierarchical Bayesian beliefs about target motion. We hope to apply this paradigm to subjects with schizophrenia, whose pursuit abnormalities may result from the abnormal encoding of precision.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Rick A Adams; Markus Bauer; Dimitris Pinotsis; Karl J Friston

Dynamic causal modelling of eye movements during pursuit: Confirming precision-encoding in V1 using MEG Journal Article

Neuroimage, 132 , pp. 175–189, 2016.

Abstract | Links | BibTeX

@article{Adams2016,
title = {Dynamic causal modelling of eye movements during pursuit: Confirming precision-encoding in V1 using MEG},
author = {Rick A Adams and Markus Bauer and Dimitris Pinotsis and Karl J Friston},
doi = {10.1016/j.neuroimage.2016.02.055},
year = {2016},
date = {2016-01-01},
journal = {Neuroimage},
volume = {132},
pages = {175--189},
publisher = {The Authors},
abstract = {This paper shows that it is possible to estimate the subjective precision (inverse variance) of Bayesian beliefs during oculomotor pursuit. Subjects viewed a sinusoidal target, with or without random fluctuations in its motion. Eye trajectories and magnetoencephalographic (MEG) data were recorded concurrently. The target was periodically occluded, such that its reappearance caused a visual evoked response field (ERF). Dynamic causal modelling (DCM) was used to fit models of eye trajectories and the ERFs. The DCM for pursuit was based on predictive coding and active inference, and predicts subjects' eye movements based on their (subjective) Bayesian beliefs about target (and eye) motion. The precisions of these hierarchical beliefs can be inferred from behavioural (pursuit) data. The DCM for MEG data used an established biophysical model of neuronal activity that includes parameters for the gain of superficial pyramidal cells, which is thought to encode precision at the neuronal level. Previous studies (using DCM of pursuit data) suggest that noisy target motion increases subjective precision at the sensory level: i.e., subjects attend more to the target's sensory attributes. We compared (noisy motion-induced) changes in the synaptic gain based on the modelling of MEG data to changes in subjective precision estimated using the pursuit data. We demonstrate that imprecise target motion increases the gain of superficial pyramidal cells in V1 (across subjects). Furthermore, increases in sensory precision – inferred by our behavioural DCM – correlate with the increase in gain in V1, across subjects. This is a step towards a fully integrated model of brain computations, cortical responses and behaviour that may provide a useful clinical tool in conditions like schizophrenia.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Hossein Adeli; Françoise Vitu; Gregory J Zelinsky

A model of the superior colliculus predicts fixation locations during scene viewing and visual aearch Journal Article

Journal of Neuroscience, 37 (6), pp. 1453–1467, 2017.

Abstract | Links | BibTeX

@article{Adeli2017,
title = {A model of the superior colliculus predicts fixation locations during scene viewing and visual aearch},
author = {Hossein Adeli and Fran{ç}oise Vitu and Gregory J Zelinsky},
doi = {10.1523/JNEUROSCI.0825-16.2016},
year = {2017},
date = {2017-01-01},
journal = {Journal of Neuroscience},
volume = {37},
number = {6},
pages = {1453--1467},
abstract = {Modern computational models of attention predict fixations using saliency maps and target maps, which prioritize locations for fixation based on feature contrast and target goals, respectively. But whereas many such models are biologically plausible, none have looked to the oculomotor system for design constraints or parameter specification. Conversely, although most models of saccade programming are tightly coupled to underlying neurophysiology, none have been tested using real-world stimuli and tasks. We combined the strengths of these two approaches in MASC, a model of attention in the superior colliculus (SC) that captures known neurophysiological constraints on saccade programming. We show that MASC predicted the fixation locations of humans freely viewing naturalistic scenes and performing exemplar and categorical search tasks, a breadth achieved by no other existing model. Moreover, it did this as well or better than its more specialized state-of-the-art competitors. MASC's predictive success stems from its inclusion of high-level but core principles of SC organization: an over-representation of foveal information, size-invariant population codes, cascaded population averaging over distorted visual and motor maps, and competition between motor point images for saccade programming, all of which cause further modulation of priority (attention) after projection of saliency and target maps to the SC. Only by incorporating these organizing brain principles into our models can we fully understand the transformation of complex visual information into the saccade programs underlying movements of overt attention. With MASC, a theoretical footing now exists to generate and test computationally explicit predictions of behavioral and neural responses in visually complex real-world contexts.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Kivilcim Afacan-Seref; Natalie A Steinemann; Annabelle Blangero; Simon P Kelly

Dynamic interplay of value and sensory information in high-speed decision making Journal Article

Current Biology, 28 (5), pp. 795–802, 2018.

Abstract | Links | BibTeX

@article{Afacan-Seref2018,
title = {Dynamic interplay of value and sensory information in high-speed decision making},
author = {Kivilcim Afacan-Seref and Natalie A Steinemann and Annabelle Blangero and Simon P Kelly},
doi = {10.1016/j.cub.2018.01.071},
year = {2018},
date = {2018-03-01},
journal = {Current Biology},
volume = {28},
number = {5},
pages = {795--802},
abstract = {In dynamic environments, split-second sensorimotor decisions must be prioritized according to potential payoffs to maximize overall rewards. The impact of relative value on deliberative perceptual judgments has been examined extensively [1–6], but relatively little is known about value-biasing mechanisms in the common situation where physical evidence is strong but the time to act is severely limited. In prominent decision models, a noisy but statistically stationary representation of sensory evidence is integrated over time to an action-triggering bound, and value-biases are affected by starting the integrator closer to the more valuable bound. Here, we show significant departures from this account for humans making rapid sensory-instructed action choices. Behavior was best explained by a simple model in which the evidence representation—and hence, rate of accumulation—is itself biased by value and is non-stationary, increasing over the short decision time frame. Because the value bias initially dominates, the model uniquely predicts a dynamic ‘‘turn-around'' effect on low-value cues, where the accumulator first launches toward the incorrect action but is then re-routed to the correct one. This was clearly exhibited in electrophysiological signals reflecting motor preparation and evidence accumulation. Finally, we construct an extended model that implements this dynamic effect through plausible sensory neural response modulations and demonstrate the correspondence between decision signal dynamics simulated from a behavioral fit of that model and the empirical decision signals. Our findings suggest that value and sensory information can exert simultaneous and dynamically countervailing influences on the trajectory of the accumulation-to-bound process, driving rapid, sensory-guided actions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Arash Afraz; Patrick Cavanagh

The gender-specific face aftereffect is based in retinotopic not spatiotopic coordinates across several natural image transformations Journal Article

Journal of Vision, 9 (10), pp. 1–17, 2009.

Abstract | Links | BibTeX

Zaeinab Afsari; José P Ossandón; Peter Konig

The dynamic effect of reading direction habit on spatial asymmetry of image perception Journal Article

Journal of Vision, 16 (11), pp. 1–21, 2016.

Abstract | Links | BibTeX

@article{Afsari2016,
title = {The dynamic effect of reading direction habit on spatial asymmetry of image perception},
author = {Zaeinab Afsari and José P Ossandón and Peter Konig},
doi = {10.1167/16.11.8.doi},
year = {2016},
date = {2016-01-01},
journal = {Journal of Vision},
volume = {16},
number = {11},
pages = {1--21},
abstract = {Exploration of images after stimulus onset is initially biased to the left. Here, we studied the causes of such an asymmetry and investigated effects of reading habits, text primes, and priming by systematically biased eye movements on this spatial bias in visual exploration. Bilinguals first read text primes with right- to-left (RTL) or left-to-right (LTR) reading directions and subsequently explored natural images. In Experiment 1, native RTL speakers showed a leftward free-viewing shift after reading LTR primes but a weaker rightward bias after reading RTL primes. This demonstrates that reading direction dynamically influences the spatial bias. However, native LTR speakers wholearnedanRTL languagelateinlife showed a leftward bias after reading either LTR or RTL primes, which suggests the role of habit formation in the production of the spatial bias. In Experiment 2, LTR bilinguals showed a slightly enhanced leftward bias after reading LTR text primes in their second language. This might contribute to the differences of native RTL and LTR speakers observed in Experiment 1. In Experiment 3, LTR bilinguals read normal (LTR, habitual reading) and mirrored left-to-right (mLTR, nonhabitual reading) texts. We observed a strong leftward bias in both cases, indicating that the bias direction is influenced by habitual reading direction and is not secondary to the actual reading direction. This is confirmed in Experiment 4, in which LTR participants were asked to follow RTL and LTR moving dots in prior image presentation and showed no change in the normal spatial bias. In conclusion, the horizontal bias is a dynamic property and is modulated by habitual reading direction. Introduction},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Zaeinab Afsari; Ashima Keshava; José P Ossandón; Peter König

Interindividual differences among native right-to-left readers and native left-to-right readers during free viewing task Journal Article

Visual Cognition, 26 (6), pp. 430–441, 2018.

Abstract | Links | BibTeX

@article{Afsari2018,
title = {Interindividual differences among native right-to-left readers and native left-to-right readers during free viewing task},
author = {Zaeinab Afsari and Ashima Keshava and José P Ossandón and Peter König},
doi = {10.1080/13506285.2018.1473542},
year = {2018},
date = {2018-01-01},
journal = {Visual Cognition},
volume = {26},
number = {6},
pages = {430--441},
abstract = {Human visual exploration is not homogeneous but displays spatial biases. Specifically, early after the onset of a visual stimulus, the majority of eye movements target the left visual space. This horizontal asymmetry of image exploration is rather robust with respect to multiple image manipulations, yet can be dynamically modulated by preceding text primes. This characteristic points to an involvement of reading habits in the deployment of visual attention. Here, we report data of native right-to-left (RTL) readers with a larger variation and stronger modulation of horizontal spatial bias in comparison to native left-to-right (LTR) readers after preceding text primes. To investigate the influences of biological and cultural factors, we measure the correlation of the modulation of the horizontal spatial bias for native RTL readers and native LTR readers with multiple factors: age, gender, second language proficiency, and age at which the second language was acquired. The results demonstrate only weak or no correlations between the magnitude of the horizontal bias and the previously mentioned factors. We conclude that the spatial bias of viewing behaviour for native RTL readers is more variable than for native LTR readers, and this variance could not be demonstrated to be associated with interindividual differences. We speculate the role of strength of habit and/or the interindividual differences in the structural and functional brain regions as a cause of the RTL spatial bias among RTL native readers.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mehmet N Ağaoğlu; Michael H Herzog; Haluk Öğmen

Field-like interactions between motion-based reference frames Journal Article

Attention, Perception, & Psychophysics, 77 (6), pp. 2082–2097, 2015.

Abstract | Links | BibTeX

@article{Agaoglu2015,
title = {Field-like interactions between motion-based reference frames},
author = {Mehmet N Ağaoğlu and Michael H Herzog and Haluk Öğmen},
doi = {10.3758/s13414-015-0890-9},
year = {2015},
date = {2015-01-01},
journal = {Attention, Perception, & Psychophysics},
volume = {77},
number = {6},
pages = {2082--2097},
abstract = {A reference frame is required to specify how motion is perceived. For example, the motion ofpart ofan object is usually perceived relative to the motion of the object itself. Johansson (Psychological Research, 38,379–393, 1976)pro-posed that the perceptual system carries out a vector decomposition, which rewsults in common and relative motion percepts. Because vector decomposition is an ill-posed problem, several studies have introduced constraints by means ofwhich the number of solutions can be substantially reduced. Here, we have adopted an alternative approach and studied how, rather than why, a subset ofsolutions is selected by the visual system. We propose that each retinotopic motion vector creates a reference-frame field in the retinotopic space, and that the fields created by different motion vectors interact in order to determine a motion vector that will serve as the reference frame at a given point and time in space. To test this theory, we performed a set ofpsychophysical experiments. The field-like influence of motion-based reference frames was manifested by increased nonspatiotopic percepts of the backward motion of a target square with decreasing distance from a drifting grating. We then sought to determine whether these field-like effects ofmotion-based reference frames can also be extended to stationary landmarks. The results suggest that reference-field interactions occur only between motion-generated fields. Finally, we investigated whether and how different reference fields interact with each other, and found that different reference-field interactions are nonlinear and depend on how the motion vectors are grouped. These findings are discussed from the perspective ofthe reference-frame metric field (RFMF) theory, according to which perceptual grouping operations play a central and essential role in determining the prevailing reference frames.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mehmet N Ağaoğlu; Michael H Herzog; Haluk Öğmen

The effective reference frame in perceptual judgments of motion direction Journal Article

Vision Research, 107 , pp. 101–112, 2015.

Abstract | Links | BibTeX

Mehmet N Ağaoğlu; Susana T L Chung

Can (should) theories of crowding be unified? Journal Article

Journal of Vision, 16 (15), pp. 1–22, 2016.

Abstract | Links | BibTeX

Mehmet N Ağaoğlu; Aaron M Clarke; Michael H Herzog; Haluk Ögmen

Motion-based nearest vector metric for reference frame selection in the perception of motion Journal Article

Journal of Vision, 16 (7), pp. 1–16, 2016.

Abstract | Links | BibTeX

@article{Agaoglu2016a,
title = {Motion-based nearest vector metric for reference frame selection in the perception of motion},
author = {Mehmet N Ağaoğlu and Aaron M Clarke and Michael H Herzog and Haluk Ögmen},
doi = {10.1167/16.7.14},
year = {2016},
date = {2016-01-01},
journal = {Journal of Vision},
volume = {16},
number = {7},
pages = {1--16},
abstract = {We investigated how the visual system selects a reference frame for the perception of motion. Two concentric arcs underwent circular motion around the center of the display, where observers fixated. The outer (target) arc's angular velocity profile was modulated by a sine wave midflight whereas the inner (reference) arc moved at a constant angular speed. The task was to report whether the target reversed its direction of motion at any point during its motion. We investigated the effects of spatial and figural factors by systematically varying the radial and angular distances between the arcs, and their relative sizes. We found that the effectiveness of the reference frame decreases with increasing radial- and angular-distance measures. Drastic changes in the relative sizes of the arcs did not influence motion reversal thresholds, suggesting no influence of stimulus form on perceived motion. We also investigated the effect of common velocity by introducing velocity fluctuations to the reference arc as well. We found no effect of whether or not a reference frame has a constant motion. We examined several form- and motion-based metrics, which could potentially unify our findings. We found that a motion-based nearest vector metric can fully account for all the data reported here. These findings suggest that the selection of reference frames for motion processing does not result from a winner-take-all process, but instead, can be explained by a field whose strength decreases with the distance between the nearest motion vectors regardless of the form of the moving objects.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mehmet N Ağaoğlu; Haluk Öğmen; Susana T L Chung

Unmasking saccadic uncrowding Journal Article

Vision Research, 127 , pp. 152–164, 2016.

Abstract | Links | BibTeX

@article{Agaoglu2016b,
title = {Unmasking saccadic uncrowding},
author = {Mehmet N Ağaoğlu and Haluk Öğmen and Susana T L Chung},
doi = {10.1016/j.visres.2016.08.003},
year = {2016},
date = {2016-01-01},
journal = {Vision Research},
volume = {127},
pages = {152--164},
abstract = {Stimuli that are briefly presented around the time of saccades are often perceived with spatiotemporal distortions. These distortions do not always have deleterious effects on the visibility and identification of a stimulus. Recent studies reported that when a stimulus is the target of an intended saccade, it is released from both masking and crowding. Here, we investigated pre-saccadic changes in single and crowded letter recognition performance in the absence (Experiment 1) and the presence (Experiment 2) of backward masks to determine the extent to which saccadic “uncrowding” and “unmasking” mechanisms are similar. Our results show that pre-saccadic improvements in letter recognition performance are mostly due to the presence of masks and/or stimulus transients which occur after the target is presented. More importantly, we did not find any decrease in crowding strength before impending saccades. A simplified version of a dual-channel neural model, originally proposed to explain masking phenomena, with several saccadic add-on mechanisms, could account for our results in Experiment 1. However, this model falls short in explaining how saccades drastically reduced the effect of backward masking (Experiment 2). The addition of a remapping mechanism that alters the relative spatial positions of stimuli was needed to fully account for the improvements observed when backward masks followed the letter stimuli. Taken together, our results (i) are inconsistent with saccadic uncrowding, (ii) strongly support saccadic unmasking, and (iii) suggest that pre-saccadic letter recognition is modulated by multiple perisaccadic mechanisms with different time courses.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mehmet N Ağaoğlu; Susana T L Chung

Interaction between stimulus contrast and pre-saccadic crowding Journal Article

Royal Society Open Science, 4 (2), pp. 1–17, 2017.

Abstract | Links | BibTeX

Dimitris Agrafiotis; Nishan Canagarajah; David R Bull; Matthew Dye

Perceptually optimised sign language video coding based on eye tracking analysis Journal Article

Electronics Letters, 39 , pp. 1–2, 2003.

Abstract | Links | BibTeX

Dimitris Agrafiotis; Nishan Canagarajah; David R Bull; Jim Kyle; Helen Seers; Matthew Dye

A perceptually optimised video coding system for sign language communication at low bit rates Journal Article

Signal Processing: Image Communication, 21 (7), pp. 531–549, 2006.

Abstract | Links | BibTeX

Jordi Aguila; Javier Cudeiro; Casto Rivadulla

Effects of static magnetic fields on the visual cortex: Reversible visual deficits and reduction of neuronal activity Journal Article

Cerebral Cortex, 26 , pp. 628–638, 2016.

Abstract | Links | BibTeX

Jordi Aguila; Javier F Cudeiro; Casto Rivadulla

Suppression of V1 feedback produces a shift in the topographic representation of receptive fields of LGN cells by unmasking latent retinal drives Journal Article

Cerebral Cortex, 27 (6), pp. 3331–3345, 2017.

Abstract | Links | BibTeX

Carlos Aguilar; Eric Castet

Gaze-contingent simulation of retinopathy: Some potential pitfalls and remedies Journal Article

Vision Research, 51 (9), pp. 997–1012, 2011.

Abstract | Links | BibTeX

Carlos Aguilar; Eric Castet

Evaluation of a gaze-controlled vision enhancement system for reading in visually impaired people Journal Article

PLoS ONE, 12 (4), pp. 1–24, 2017.

Abstract | Links | BibTeX

@article{Aguilar2017,
title = {Evaluation of a gaze-controlled vision enhancement system for reading in visually impaired people},
author = {Carlos Aguilar and Eric Castet},
doi = {10.1371/journal.pone.0174910},
year = {2017},
date = {2017-01-01},
journal = {PLoS ONE},
volume = {12},
number = {4},
pages = {1--24},
abstract = {People with low vision, especially those with Central Field Loss (CFL), need magnification to read. The flexibility of Electronic Vision Enhancement Systems (EVES) offers several ways of magnifying text. Due to the restricted field of view of EVES, the need for magnification is conflicting with the need to navigate through text (panning). We have developed and implemented a real-time gaze-controlled system whose goal is to optimize the possibility of magnifying a portion of text while maintaining global viewing of the other portions of the text (condition 1). Two other conditions were implemented that mimicked commercially available advanced systems known as CCTV (closed-circuit television systems)-conditions 2 and 3. In these two conditions, magnification was uniformly applied to the whole text without any possibility to specifically select a region of interest. The three conditions were implemented on the same computer to remove differences that might have been induced by dissimilar equipment. A gaze-contingent artificial 10° scotoma (a mask continuously displayed in real time on the screen at the gaze location) was used in the three conditions in order to simulate macular degeneration. Ten healthy subjects with a gaze-contingent scotoma read aloud sentences from a French newspaper in nine experimental one-hour sessions. Reading speed was measured and constituted the main dependent variable to compare the three conditions. All subjects were able to use condition 1 and they found it slightly more comfortable to use than condition 2 (and similar to condition 3). Importantly, reading speed results did not show any significant difference between the three systems. In addition, learning curves were similar in the three conditions. This proof of concept study suggests that the principles underlying the gaze-controlled enhanced system might be further developed and fruitfully incorporated in different kinds of EVES for low vision reading.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Stephanie Ahken; Gilles Comeau; Sylvie Hébert; Ramesh Balasubramaniam

Eye movement patterns during the processing of musical and linguistic syntactic incongruities. Journal Article

Psychomusicology: Music, Mind, and Brain, 22 (1), pp. 18–25, 2012.

Abstract | Links | BibTeX

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

Experimental Brain Research, 232 (3), pp. 1025–1036, 2014.

Abstract | Links | BibTeX

@article{Ahlen2014,
title = {Learning to read upside-down: A study of perceptual expertise and its acquisition},
author = {Elsa Ahlén and Charlotte S Hills and Hashim M Hanif and Cristina Rubino and Jason J S Barton},
doi = {10.1007/s00221-013-3813-9},
year = {2014},
date = {2014-01-01},
journal = {Experimental Brain Research},
volume = {232},
number = {3},
pages = {1025--1036},
abstract = {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.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Sheeraz Ahmad; He Huang; Angela J Yu

Cost-sensitive Bayesian control policy in human active sensing Journal Article

Frontiers in Human Neuroscience, 8 (December), pp. 1–12, 2014.

Abstract | Links | BibTeX

@article{Ahmad2014,
title = {Cost-sensitive Bayesian control policy in human active sensing},
author = {Sheeraz Ahmad and He Huang and Angela J Yu},
doi = {10.3389/fnhum.2014.00955},
year = {2014},
date = {2014-01-01},
journal = {Frontiers in Human Neuroscience},
volume = {8},
number = {December},
pages = {1--12},
abstract = {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.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mehrnoosh Ahmadi; Mitra Judi; Anahita Khorrami; Javad Mahmoudi-Gharaei; Mehdi Tehrani-Doost

Initial orientation of attention towards emotional faces in children with attention deficit hyperactivity disorder Journal Article

Iranian Journal of Psychiatry, 6 (3), pp. 87–91, 2011.

Abstract | BibTeX

Désirée S Aichert; Nicola M Wöstmann; Anna Costa; Christine Macare; Johanna R Wenig; Hans-Jürgen Möller; Katya Rubia; Ulrich Ettinger

Associations between trait impulsivity and prepotent response inhibition Journal Article

Journal of Clinical and Experimental Neuropsychology, 34 (10), pp. 37–41, 2012.

Abstract | Links | BibTeX

@article{Aichert2012,
title = {Associations between trait impulsivity and prepotent response inhibition},
author = {Désirée S Aichert and Nicola M Wöstmann and Anna Costa and Christine Macare and Johanna R Wenig and Hans-Jürgen Möller and Katya Rubia and Ulrich Ettinger},
doi = {10.1080/13803395.2012.706261},
year = {2012},
date = {2012-01-01},
journal = {Journal of Clinical and Experimental Neuropsychology},
volume = {34},
number = {10},
pages = {37--41},
abstract = {This study addresses the relationship between trait impulsivity and inhibitory control, two features known to be impaired in a number ofpsychiatric conditions. While impulsivity is often measured using psychometric self-report questionnaires, the inhibition ofinappropriate, impulsive motor responses is typically measured using experimental laboratory tasks. It remains unclear, however, whether psychometrically assessed impulsivity and experimentally operationalized inhibitory performance are related to each other. Therefore, we investigated the relationship between these two traits in a large sample using correlative and latent variable analysis. A total of 504 healthy individuals completed the Barratt Impulsiveness Scale (BIS-11) and a battery of four prepotent response inhibi- tion paradigms: the antisaccade, Stroop, stop-signal, and go/no-go tasks. We found significant associations of BIS impulsivity with commission errors on the go/no-go task and directional errors on the antisaccade task, over and above effects of age, gender, and intelligence. Latent variable analysis (a) supported the idea that all four inhibitory measures load on the same underlying construct termed “prepotent response inhibition” and (b) revealed that 12% of variance of the prepotent response inhibition construct could be explained by BIS impulsivity. Overall, the magnitude of associations observed was small, indicating that while a portion of variance in prepotent response inhibition can be explained by psychometric trait impulsivity, the majority of variance remains unexplained. Thus, these findings suggest that prepotent response inhibition paradigms can account for psychometric trait impulsivity only to a limited extent. Implications for studies of patient populations with symptoms of impulsivity are discussed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Désirée S Aichert; Birgit Derntl; Nicola M Wöstmann; Julia K Groß; Sandra Dehning; Anja Cerovecki; Hans-Jürgen Möller; Ute Habel; Michael Riedel; Ulrich Ettinger

Intact emotion-cognition interaction in schizophrenia patients and first-degree relatives: Evidence from an emotional antisaccade task Journal Article

Brain and Cognition, 82 (3), pp. 329–336, 2013.

Abstract | Links | BibTeX

@article{Aichert2013,
title = {Intact emotion-cognition interaction in schizophrenia patients and first-degree relatives: Evidence from an emotional antisaccade task},
author = {Désirée S Aichert and Birgit Derntl and Nicola M Wöstmann and Julia K Groß and Sandra Dehning and Anja Cerovecki and Hans-Jürgen Möller and Ute Habel and Michael Riedel and Ulrich Ettinger},
doi = {10.1016/j.bandc.2013.05.007},
year = {2013},
date = {2013-01-01},
journal = {Brain and Cognition},
volume = {82},
number = {3},
pages = {329--336},
publisher = {Elsevier Inc.},
abstract = {Schizophrenia patients have deficits in cognitive control as well as in a number of emotional domains. The antisaccade task is a measure of cognitive control that requires the inhibition of a reflex-like eye movement to a peripheral stimulus. Antisaccade performance has been shown to be modulated by the emotional content of the peripheral stimuli, with emotional stimuli leading to higher error rates than neutral stimuli, reflecting an implicit emotion processing effect. The aim of the present study was to investigate the impact on antisaccade performance of threat-related emotional facial stimuli in schizophrenia patients, first-degree relatives of schizophrenia patients and healthy controls. Fifteen patients, 22 relatives and 26 controls, matched for gender, age and verbal intelligence, carried out an antisaccade task with pictures of faces displaying disgusted, fearful and neutral expressions as peripheral stimuli. We observed higher antisaccade error rates in schizophrenia patients compared to first-degree relatives and controls. Relatives and controls did not differ significantly from each other. Antisaccade error rate was influenced by the emotional nature of the stimuli: participants had higher antisaccade error rates in response to fearful faces compared to neutral and disgusted faces. As this emotional influence on cognitive control did not differ between groups we conclude that implicit processing of emotional faces is intact in patients with schizophrenia and those at risk for the illness.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

C J Aine; H J Bockholt; J R Bustillo; J M Cañive; A Caprihan; C Gasparovic; F M Hanlon; J M Houck; R E Jung; J Lauriello; J Liu; A R Mayer; N I Perrone-Bizzozero; S Posse; J M Stephen; J A Turner; V P Clark; Vince D Calhoun

Multimodal neuroimaging in schizophrenia: Description and dissemination Journal Article

Neuroinformatics, 15 (4), pp. 343–364, 2017.

Abstract | Links | BibTeX

Cordelia D Aitkin; Elio M Santos; Eileen Kowler

Anticipatory smooth eye movements in autism spectrum disorder Journal Article

PLoS ONE, 8 (12), pp. 1–11, 2013.

Abstract | Links | BibTeX

@article{Aitkin2013,
title = {Anticipatory smooth eye movements in autism spectrum disorder},
author = {Cordelia D Aitkin and Elio M Santos and Eileen Kowler},
doi = {10.1371/journal.pone.0083230},
year = {2013},
date = {2013-01-01},
journal = {PLoS ONE},
volume = {8},
number = {12},
pages = {1--11},
abstract = {Smooth pursuit eye movements are important for vision because they maintain the line of sight on targets that move smoothly within the visual field. Smooth pursuit is driven by neural representations of motion, including a surprisingly strong influence of high-level signals representing expected motion. We studied anticipatory smooth eye movements (defined as smooth eye movements in the direction of expected future motion) produced by salient visual cues in a group of high-functioning observers with Autism Spectrum Disorder (ASD), a condition that has been associated with difficulties in either generating predictions, or translating predictions into effective motor commands. Eye movements were recorded while participants pursued the motion of a disc that moved within an outline drawing of an inverted Y-shaped tube. The cue to the motion path was a visual barrier that blocked the untraveled branch (right or left) of the tube. ASD participants showed strong anticipatory smooth eye movements whose velocity was the same as that of a group of neurotypical participants. Anticipatory smooth eye movements appeared on the very first cued trial, indicating that trial-by-trial learning was not responsible for the responses. These results are significant because they show that anticipatory capacities are intact in high-functioning ASD in cases where the cue to the motion path is highly salient and unambiguous. Once the ability to generate anticipatory pursuit is demonstrated, the study of the anticipatory responses with a variety of types of cues provides a window into the perceptual or cognitive processes that underlie the interpretation of events in natural environments or social situations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Avigael M Aizenman; Trafton Drew; Krista A Ehinger; Dianne Georgian-smith; Jeremy M Wolfe

Comparing search patterns in digital breast tomosynthesis and full-field digital mammography: An eye tracking study Journal Article

Journal of Medical Imaging, 4 (4), pp. 1–22, 2017.

Abstract | Links | BibTeX

Suzon Ajasse; Ryad B Benosman; Jean Lorenceau

Effects of pupillary responses to luminance and attention on visual spatial discrimination Journal Article

Journal of Vision, 18 (11), pp. 1–14, 2018.

Abstract | Links | BibTeX

@article{Ajasse2018,
title = {Effects of pupillary responses to luminance and attention on visual spatial discrimination},
author = {Suzon Ajasse and Ryad B Benosman and Jean Lorenceau},
doi = {10.1167/18.11.6},
year = {2018},
date = {2018-01-01},
journal = {Journal of Vision},
volume = {18},
number = {11},
pages = {1--14},
abstract = {The optic quality of the eyes is, at least in part, determined by pupil size. Large pupils let more light enter the eyes, but degrade the point spread function, and thus the spatial resolution that can be achieved (Campbell & Gregory, 1960). In natural conditions, the pupil is mainly driven by the luminance (and possibly the color and contrast) at the gazed location, but is also modulated by attention and cognitive factors. Whether changes in eyes' optics related to pupil size modulation by luminance and attention impacts visual processing was assessed in two experiments. In Experiment 1, we measured pupil size using a constantly visible display made of four disks with different luminance levels, with no other task than fixating the disks in succession. The results confirmed that pupil size depends on the luminance of the gazed stimulus. Experiment 2, using similar settings as Experiment 1, used a two-interval forced-choice design to test whether discriminating high spatial frequencies that requires covert attention to parafoveal stimuli is better during the fixation of bright disks that entails a small pupil size, and hence better eyes' optics, as compared to fixating dark disks that entails a large pupil size, and hence poorer eyes' optics. As in Experiment 1, we observed large modulations of pupil size depending on the luminance of the gazed stimulus, but pupil dynamics was more variable, with marked pupil dilation during stimulus encoding, presumably because the demanding spatial frequency discrimination task engaged attention. However, discrimination performance and mean pupil size were not correlated. Despite this lack of correlation, the slopes of pupil dilation during stimulus encoding were correlated to performance, while the slopes of pupil dilation during decision-making were not. We discuss these results regarding the possible functional roles of pupil size modulations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Sara Ajina; Christopher Kennard; Geraint Rees; Holly Bridge

Motion area V5/MT+ response to global motion in the absence of V1 resembles early visual cortex Journal Article

Brain, 138 (1), pp. 164–178, 2015.

Abstract | Links | BibTeX

@article{Ajina2015,
title = {Motion area V5/MT+ response to global motion in the absence of V1 resembles early visual cortex},
author = {Sara Ajina and Christopher Kennard and Geraint Rees and Holly Bridge},
doi = {10.1093/brain/awu328},
year = {2015},
date = {2015-01-01},
journal = {Brain},
volume = {138},
number = {1},
pages = {164--178},
abstract = {Motion area V5/MT+ shows a variety of characteristic visual responses, often linked to perception, which are heavily influenced by its rich connectivity with the primary visual cortex (V1). This human motion area also receives a number of inputs from other visual regions, including direct subcortical connections and callosal connections with the contralateral hemisphere. Little is currently known about such alternative inputs to V5/MT+ and how they may drive and influence its activity. Using functional magnetic resonance imaging, the response of human V5/MT+ to increasing the proportion of coherent motion was measured in seven patients with unilateral V1 damage acquired during adulthood, and a group of healthy age-matched controls. When V1 was damaged, the typical V5/MT+ response to increasing coherence was lost. Rather, V5/MT+ in patients showed a negative trend with coherence that was similar to coherence-related activity in V1 of healthy control subjects. This shift to a response-pattern more typical of early visual cortex suggests that in the absence of V1, V5/MT+ activity may be shaped by similar direct subcortical input. This is likely to reflect intact residual pathways rather than a change in connectivity, and has important implications for blindsight function. It also confirms predictions that V1 is critically involved in normal V5/MT+ global motion processing, consistent with a convergent model of V1 input to V5/MT+. Historically, most attempts to model cortical visual responses do not consider the contribution of direct subcortical inputs that may bypass striate cortex, such as input to V5/MT+. We have shown that the signal change driven by these non-striate pathways can be measured, and suggest that models of the intact visual system may benefit from considering their contribution.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Sara Ajina; Franco Pestilli; Ariel Rokem; Christopher Kennard; Holly Bridge

Human blindsight is mediated by an intact geniculo-extrastriate pathway Journal Article

eLife, 4 , pp. 1–23, 2015.

Abstract | Links | BibTeX

Sara Ajina; Geraint Rees; Christopher Kennard; Holly Bridge

Abnormal contrast responses in the extrastriate cortex of blindsight patients Journal Article

Journal of Neuroscience, 35 (21), pp. 8201–8213, 2015.

Abstract | Links | BibTeX

@article{Ajina2015b,
title = {Abnormal contrast responses in the extrastriate cortex of blindsight patients},
author = {Sara Ajina and Geraint Rees and Christopher Kennard and Holly Bridge},
doi = {10.1523/JNEUROSCI.3075-14.2015},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neuroscience},
volume = {35},
number = {21},
pages = {8201--8213},
abstract = {When the human primary visual cortex (V1) is damaged, the dominant geniculo-striate pathway can no longer convey visual information to the occipital cortex. However, many patients with such damage retain some residual visual function that must rely on an alternative pathway directly to extrastriate occipital regions. This residual vision is most robust for moving stimuli, suggesting a role for motion area hMT+. However, residual vision also requires high-contrast stimuli, which is inconsistent with hMT+ sensitivity to contrast in which even low-contrast levels elicit near-maximal neural activation. We sought to investigate this discrepancy by measuring behavioral and neural responses to increasing contrast in patients with V1 damage. Eight patients underwent behavioral testing and functional magnetic resonance imaging to record contrast sensitivity in hMT+ of their damaged hemisphere, using Gabor stimuli with a spatial frequency of 1 cycle/degrees. The responses from hMT+ of the blind hemisphere were compared with hMT+ and V1 responses in the sighted hemisphere of patients and a group of age-matched controls. Unlike hMT+, neural responses in V1 tend to increase linearly with increasing contrast, likely reflecting a dominant parvocellular channel input. Across all patients, the responses in hMT+ of the blind hemisphere no longer showed early saturation but increased linearly with contrast. Given the spatiotemporal parameters used in this study and the known direct subcortical projections from the koniocellular layers of the lateral geniculate nucleus to hMT+, we propose that this altered contrast sensitivity in hMT+ could be consistent with input from the koniocellular pathway.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Sara Ajina; Holly Bridge

Blindsight relies on a functional connection between hMT+ and the lateral geniculate nucleus, not the pulvinar Journal Article

PLoS Biology, 16 (7), pp. 1–25, 2018.

Abstract | Links | BibTeX

Başak Akdoğan; Fuat Balcı; Hedderik van Rijn

Temporal expectation indexed by pupillary response Journal Article

Timing & Time Perception, 4 , pp. 354–370, 2016.

Abstract | Links | BibTeX

Annika Åkerfelt; Hans Colonius; Adele Diederich

Visual-tactile saccadic inhibition Journal Article

Experimental Brain Research, 169 (4), pp. 554–563, 2006.

Abstract | Links | BibTeX

Ozgur E Akman; Richard A Clement; David S Broomhead; Sabira Mannan; Ian Moorhead; Hugh R Wilson

Probing bottom-up processing with multistable images Journal Article

Journal of Eye Movement Research, 1 (3), pp. 1–7, 2009.

Abstract | BibTeX

Umair Akram; Jason G Ellis; Andriy Myachykov; Nicola L Barclay

Preferential attention towards the eye-region amongst individuals with insomnia Journal Article

Journal of Sleep Research, 26 (1), pp. 84–91, 2017.

Abstract | Links | BibTeX

@article{Akram2017,
title = {Preferential attention towards the eye-region amongst individuals with insomnia},
author = {Umair Akram and Jason G Ellis and Andriy Myachykov and Nicola L Barclay},
doi = {10.1111/jsr.12456},
year = {2017},
date = {2017-01-01},
journal = {Journal of Sleep Research},
volume = {26},
number = {1},
pages = {84--91},
abstract = {People with insomnia often perceive their own facial appearance as more tired compared with the appearance of others. Evidence also highlights the eye-region in projecting tiredness cues to perceivers, and tiredness judgements often rely on preferential attention towards this region. Using a novel eye-tracking paradigm, this study examined: (i) whether individuals with insomnia display preferential attention towards the eyeregion, relative to nose and mouth regions, whilst observing faces compared with normal-sleepers; and (ii) whether an attentional bias towards the eye-region amongst individuals with insomnia is self-specific or general in nature. Twenty individuals with DSM-5 Insomnia Disorder and 20 normal-sleepers viewed 48 neutral facial photographs (24 of themselves, 24 of other people) for periods of 4000 ms. Eye movements were recorded using eye-tracking, and first fixation onset, first fixation duration and total gaze duration were examined for three interest-regions (eyes, nose, mouth). Significant group 9 interest-region interactions indicated that, regardless of the face presented, participants with insomnia were quicker to attend to, and spent more time observing, the eye-region relative to the nose and mouth regions compared with normal-sleepers. However, no group 9 face 9 interest-region interactions were established. Thus, whilst individuals with insomnia displayed preferential attention towards the eye-region in general, this effect was not accentuated during self-perception. Insomnia appears to be characterized by a general, rather than self-specific, attentional bias towards the eye-region. These findings contribute to our understanding of face perception in insomnia, and provide tentative support for cognitive models of insomnia demonstrating that individuals with insomnia monitor faces in general, with a specific focus around the eye-region, for cues associated with tiredness.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Naseem Al-aidroos; Jos J Adam; Martin H Fischer; Jay Pratt

Structured perceptual arrays and the modulation of Fitts's Law: Examining saccadic eye movements Journal Article

Journal of Motor Behavior, 40 (2), pp. 155–164, 2008.

Abstract | BibTeX

Naseem Al-Aidroos; Jay Pratt

Top-down control in time and space: Evidence from saccadic latencies and trajectories Journal Article

Visual Cognition, 18 (1), pp. 26–49, 2010.

Abstract | Links | BibTeX

Hosam Al-Samarraie; Samer Muthana Sarsam; Hans Guesgen

Predicting user preferences of environment design: A perceptual mechanism of user interface customisation Journal Article

Behaviour & Information Technology, 35 (8), pp. 644–653, 2016.

Abstract | Links | BibTeX

Noor Al-Zanoon; Michael Dambacher; Victor Kuperman

Evidence for a global oculomotor program in reading Journal Article

Psychological Research, 81 (4), pp. 863–877, 2017.

Abstract | Links | BibTeX

@article{Al-Zanoon2017,
title = {Evidence for a global oculomotor program in reading},
author = {Noor Al-Zanoon and Michael Dambacher and Victor Kuperman},
doi = {10.1007/s00426-016-0786-x},
year = {2017},
date = {2017-01-01},
journal = {Psychological Research},
volume = {81},
number = {4},
pages = {863--877},
publisher = {Springer Berlin Heidelberg},
abstract = {Recent corpus studies of eye-movements in reading revealed a substantial increase in saccade amplitudes and fixation durations as the eyes move over the first words of a sentence. This start-up effect suggests a global oculomotor program, which operates on the level of an entire line, in addition to the well-established local programs operating within the visual span. The present study investigates the nature of this global program experimentally and examines whether the start-up effect is predicated on generic visual or specific linguistic characteristics and whether it is mainly reflected in saccade amplitudes, fixation durations or both measures. Eye movements were recorded while 38 participants read (a) normal sentences, (b) sequences of randomly shuffled words and (c) sequences of z-strings. The stimuli were, therefore, similar in their visual features, but varied in the amount of syntactic and lexical information. Further, the stimuli were composed of words or strings that either varied naturally in length (Nonequal condition) or were all restricted to a specific length within a sentence (Equal). The latter condition constrained the variability of saccades and served to dissociate effects of word position in line on saccade amplitudes and fixation durations. A robust start-up effect emerged in saccade amplitudes in all Nonequal stimuli, and-in an attenuated form-in Equal sentences. A start-up effect in single fixation durations was observed in Nonequal and Equal normal sentences, but not in z-strings. These findings support the notion of a global oculomotor program in reading particularly for the spatial characteristics of motor planning, which rely on visual rather than linguistic information.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Nadia Alahyane; Denis Pélisson

Adaptation of saccadic eye movements: Transfer and specificity Journal Article

Annals of New York Academy of Sciences, 1004 (1), pp. 69–77, 2003.

Abstract | Links | BibTeX

Nadia Alahyane; Ansgar Koene; Denis Pélisson

Transfer of adaptation from visually guided saccades to averaging saccades elicited by double visual targets Journal Article

European Journal of Neuroscience, 20 (3), pp. 827–836, 2004.

Abstract | Links | BibTeX

@article{Alahyane2004,
title = {Transfer of adaptation from visually guided saccades to averaging saccades elicited by double visual targets},
author = {Nadia Alahyane and Ansgar Koene and Denis Pélisson},
doi = {10.1111/j.1460-9568.2004.03536.x},
year = {2004},
date = {2004-01-01},
journal = {European Journal of Neuroscience},
volume = {20},
number = {3},
pages = {827--836},
abstract = {The adaptive mechanisms that control the amplitude of visually guided saccades (VGS) are only partially elucidated. In this study, we investigated, in six human subjects, the transfer of VGS adaptation to averaging saccades elicited by the simultaneous presentation of two visual targets. The generation of averaging saccades requires the transformation of two representations encoding the desired eye displacement toward each of the two targets into a single representation encoding the averaging saccade (averaging programming site). We aimed to evaluate whether VGS adaptation acts upstream (hypothesis 1) or at/below (hypothesis 2) the level of averaging saccades programming. Using the double-step target paradigm, we simultaneously induced a backward adaptation of 17.5 degrees horizontal VGS and a forward adaptation of 17.5 degrees oblique VGS performed along the +/- 40 degrees directions relative to the azimuth. We measured the effects of this dual adaptation protocol on averaging saccades triggered by two simultaneous targets located at 17.5 degrees along the +/- 40 degrees directions. To increase the yield of averaging saccades, we instructed the subjects to move their eyes as fast as possible to an intermediate position between the two targets. We found that the amplitude of averaging saccades was smaller after VGS adaptation than before and differed significantly from that predicted by hypothesis 1, but not by hypothesis 2, with an adaptation transfer of 50%. These findings indicate that VGS adaptation largely occurs at/below the averaging saccade programming site. Based on current knowledge of the neural substrate of averaging saccades, we suggest that VGS adaptation mainly acts at the level of the superior colliculus or downstream.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Nadia Alahyane; Denis Pélisson

Eye position specificity of saccadic adaptation Journal Article

Investigative Ophthalmology & Visual Science, 45 (1), pp. 123–130, 2004.

Abstract | Links | BibTeX

Nadia Alahyane; Denis Pélisson

Retention of saccadic adaptation in humans Journal Article

Annals of the New York Academy of Sciences, 1039 , pp. 558–562, 2005.

Abstract | Links | BibTeX

Nadia Alahyane; Denis Pélisson

Long-lasting modifications of saccadic eye movements following adaptation induced in the double-step target paradigm Journal Article

Learning and Memory, 12 (4), pp. 433–443, 2005.

Abstract | Links | BibTeX

@article{Alahyane2005a,
title = {Long-lasting modifications of saccadic eye movements following adaptation induced in the double-step target paradigm},
author = {Nadia Alahyane and Denis Pélisson},
doi = {10.1101/lm.96405},
year = {2005},
date = {2005-01-01},
journal = {Learning and Memory},
volume = {12},
number = {4},
pages = {433--443},
abstract = {The adaptation of saccadic eye movements to environmental changes occurring throughout life is a good model of motor learning and motor memory. Numerous studies have analyzed the behavioral properties and neural substrate of oculomotor learning in short-term saccadic adaptation protocols, but to our knowledge, none have tested the persistence of the oculomotor memory. In the present study, the double-step target protocol was used in five human subjects to adaptively decrease the amplitude of reactive saccades triggered by a horizontally-stepping visual target. We tested the amplitude of visually guided saccades just before and at different times (up to 19 days) after the adaptation session. The results revealed that immediately after the adaptation session, saccade amplitude was significantly reduced by 22% on average. Although progressively recovering over days, this change in saccade gain was still statistically significant on days 1 and 5, with an average retention rate of 36% and 19%, respectively. On day 11, saccade amplitude no longer differed from the pre-adaptation value. Adaptation was more effective and more resistant to recovery for leftward saccades than for rightward ones. Lastly, modifications of saccade gain related to adaptation were accompanied by a decrease of both saccade duration and peak velocity. A control experiment indicated that all these findings were specifically related to the adaptation protocol, and further revealed that no change in the main sequence relationships could be specifically related to adaptation. We conclude that in humans, the modifications of saccade amplitude that quickly develop during a double-step target adaptation protocol can remain in memory for a much longer period of time, reflecting enduring plastic changes in the brain.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Nadia Alahyane; Roméo Salemme; Christian Urquizar; Julien Cotti; Alain Guillaume; Jean-Louis Vercher; Denis Pélisson

Oculomotor plasticity: Are mechanisms of adaptation for reactive and voluntary saccades separate? Journal Article

Brain Research, 1135 (1), pp. 107–121, 2007.

Abstract | Links | BibTeX

@article{Alahyane2007,
title = {Oculomotor plasticity: Are mechanisms of adaptation for reactive and voluntary saccades separate?},
author = {Nadia Alahyane and Roméo Salemme and Christian Urquizar and Julien Cotti and Alain Guillaume and Jean-Louis Vercher and Denis Pélisson},
doi = {10.1016/j.brainres.2006.11.077},
year = {2007},
date = {2007-01-01},
journal = {Brain Research},
volume = {1135},
number = {1},
pages = {107--121},
abstract = {Saccadic eye movements are permanently controlled and their accuracy maintained by adaptive mechanisms that compensate for physiological or pathological perturbations. In contrast to the adaptation of reactive saccades (RS) which are automatically triggered by the sudden appearance of a single target, little is known about the adaptation of voluntary saccades which allow us to intentionally scan our environment in nearly all our daily activities. In this study, we addressed this issue in human subjects by determining the properties of adaptation of scanning voluntary saccades (SVS) and comparing these features to those of RS. We also tested the reciprocal transfers of adaptation between the two saccade types. Our results revealed that SVS and RS adaptations disclosed similar adaptation fields, time course and recovery levels, with only a slightly lower after-effect for SVS. Moreover, RS and SVS main sequences both remained unaffected after adaptation. Finally and quite unexpectedly, the pattern of adaptation transfers was asymmetrical, with a much stronger transfer from SVS to RS (79%) than in the reverse direction (22%). These data demonstrate that adaptations of RS and SVS share several behavioural properties but at the same time rely on partially distinct processes. Based on these findings, it is proposed that adaptations of RS and SVS may involve a neural network including both a common site and two separate sites specifically recruited for each saccade type.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

N Alahyane; V Fonteille; C Urquizar; R Salemme; N Nighoghossian; D Pelisson; C Tilikete

Separate neural substrates in the human cerebellum for sensory-motor adaptation of reactive and of scanning voluntary saccades Journal Article

Cerebellum, 7 (4), pp. 595–601, 2008.

Abstract | Links | BibTeX

@article{Alahyane2008a,
title = {Separate neural substrates in the human cerebellum for sensory-motor adaptation of reactive and of scanning voluntary saccades},
author = {N Alahyane and V Fonteille and C Urquizar and R Salemme and N Nighoghossian and D Pelisson and C Tilikete},
doi = {10.1007/s12311-008-0065-5},
year = {2008},
date = {2008-01-01},
journal = {Cerebellum},
volume = {7},
number = {4},
pages = {595--601},
abstract = {Sensory-motor adaptation processes are critically involved in maintaining accurate motor behavior throughout life. Yet their underlying neural substrates and task-dependency bases are still poorly understood. We address these issues here by studying adaptation of saccadic eye movements, a well-established model of sensory-motor plasticity. The cerebellum plays a major role in saccadic adaptation but it has not yet been investigated whether this role can account for the known specificity of adaptation to the saccade type (e.g., reactive versus voluntary). Two patients with focal lesions in different parts of the cerebellum were tested using the double-step target paradigm. Each patient was submitted to two separate sessions: one for reactive saccades (RS) triggered by the sudden appearance of a visual target and the second for scanning voluntary saccades (SVS) performed when exploring a more complex scene. We found that a medial cerebellar lesion impaired adaptation of reactive-but not of voluntary-saccades, whereas a lateral lesion affected adaptation of scanning voluntary saccades, but not of reactive saccades. These findings provide the first evidence of an involvement of the lateral cerebellum in saccadic adaptation, and extend the demonstrated role of the cerebellum in RS adaptation to adaptation of SVS. The double dissociation of adaptive abilities is also consistent with our previous hypothesis of the involvement in saccadic adaptation of partially separated cerebellar areas specific to the reactive or voluntary task (Alahyane et al. Brain Res 1135:107-121 (2007)).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Nadia Alahyane; Anne-Dominique Devauchelle; Roméo Salemme; Denis Pélisson

Spatial transfer of adaptation of scanning voluntary saccades in humans Journal Article

Neuroreport, 19 (1), pp. 37–41, 2008.

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Nadia Alahyane; Christelle Lemoine-Lardennois; Coline Tailhefer; Thérèse Collins; Jacqueline Fagard; Karine Doré-Mazars

Development and learning of saccadic eye movements in 7- to 42-month-old children Journal Article

Journal of Vision, 16 (1), pp. 1–12, 2016.

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Denis Alamargot

Eye and Pen: A new device for studying reading Journal Article

Behavior Research Methods, 38 (2), pp. 287–299, 2006.

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Denis Alamargot; Sylvie Plane; Eric Lambert; David Chesnet

Using eye and pen movements to trace the development of writing expertise: Case studies of a 7th, 9th and 12th grader, graduate student, and professional writer Journal Article

Reading and Writing, 23 (7), pp. 853–888, 2010.

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Denis Alamargot; Lisa Flouret; Denis Larocque; Gilles Caporossi; Virginie Pontart; Carmen Paduraru; Pauline Morisset; Michel Fayol

Successful written subject–verb agreement: An online analysis of the procedure used by students in Grades 3, 5 and 12 Journal Article

Reading and Writing, 28 (3), pp. 291–312, 2015.

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Andrea Alamia; Alexandre Zénon

Statistical regularities attract attention when task-relevant Journal Article

Frontiers in Human Neuroscience, 10 , pp. 1–10, 2016.

Abstract | Links | BibTeX

@article{Alamia2016,
title = {Statistical regularities attract attention when task-relevant},
author = {Andrea Alamia and Alexandre Zénon},
doi = {10.3389/fnhum.2016.00042},
year = {2016},
date = {2016-01-01},
journal = {Frontiers in Human Neuroscience},
volume = {10},
pages = {1--10},
abstract = {Visual attention seems essential for learning the statistical regularities in our environment, a process known as statistical learning. However, how attention is allocated when exploring a novel visual scene whose statistical structure is unknown remains unclear. In order to address this question, we investigated visual attention allocation during a task in which we manipulated the conditional probability of occurrence of colored stimuli, unbeknown to the subjects. Participants were instructed to detect a target colored dot among two dots moving along separate circular paths. We evaluated implicit statistical learning, i.e. the effect of color predictability on reaction times (RT), and recorded eye position concurrently. Attention allocation was indexed by comparing the Mahalanobis distance between the position, velocity and acceleration of the eyes and the 2 colored dots. We found that learning the conditional probabilities occurred very early during the course of the experiment as shown by the fact that, starting already from the first block, predictable stimuli were detected with shorter RT than unpredictable ones. In terms of attentional allocation, we found that the predictive stimulus attracted gaze only when it was informative about the occurrence of the target but not when it predicted the occurrence of a task-irrelevant stimulus. This suggests that attention allocation was influenced by regularities only when they were instrumental in performing the task. Moreover, we found that the attentional bias towards task-relevant predictive stimuli occurred at a very early stage of learning, concomitantly with the first effects of learning on RT. In conclusion, these results show that statistical regularities capture visual attention only after a few occurrences, provided these regularities are instrumental to perform the task.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Andrea Alamia; Oleg Solopchuk; Alexandre Zénon

Strong conscious cues suppress preferential gaze allocation to unconscious cues Journal Article

Frontiers in Human Neuroscience, 12 , pp. 1–9, 2018.

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Concetta F Alberti; Peter J Bex

Binocular contrast summation and inhibition depends on spatial frequency, eccentricity and binocular disparity Journal Article

Ophthalmic and Physiological Optics, 38 (5), pp. 525–537, 2018.

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Andrea Albonico; Manuela Malaspina; Emanuela Bricolo; Marialuisa Martelli; Roberta Daini

Temporal dissociation between the focal and orientation components of spatial attention in central and peripheral vision Journal Article

Acta Psychologica, 171 , pp. 85–92, 2016.

Abstract | Links | BibTeX

@article{Albonico2016,
title = {Temporal dissociation between the focal and orientation components of spatial attention in central and peripheral vision},
author = {Andrea Albonico and Manuela Malaspina and Emanuela Bricolo and Marialuisa Martelli and Roberta Daini},
doi = {10.1016/j.actpsy.2016.10.003},
year = {2016},
date = {2016-01-01},
journal = {Acta Psychologica},
volume = {171},
pages = {85--92},
publisher = {Elsevier B.V.},
abstract = {Selective attention, i.e. the ability to concentrate one's limited processing resources on one aspect of the environment, is a multifaceted concept that includes different processes like spatial attention and its subcomponents of orienting and focusing. Several studies, indeed, have shown that visual tasks performance is positively influenced not only by attracting attention to the target location (orientation component), but also by the adjustment of the size of the attentional window according to task demands (focal component). Nevertheless, the relative weight of the two components in central and peripheral vision has never been studied. We conducted two experiments to explore whether different components of spatial attention have different effects in central and peripheral vision. In order to do so, participants underwent either a detection (Experiment 1) or a discrimination (Experiment 2) task where different types of cues elicited different components of spatial attention: a red dot, a small square and a big square (an optimal stimulus for the orientation component, an optimal and a sub-optimal stimulus for the focal component respectively). Response times and cue-size effects indicated a stronger effect of the small square or of the dot in different conditions, suggesting the existence of a dissociation in terms of mechanisms between the focal and the orientation components of spatial attention. Specifically, we found that the orientation component was stronger in periphery, while the focal component was noticeable only in central vision and characterized by an exogenous nature.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Noor Z Al Dahhan; George K Georgiou; Rickie Hung; Douglas Munoz; Rauno Parrila; John R Kirby

Eye movements of university students with and without reading difficulties during naming speed tasks Journal Article

Annals of Dyslexia, 64 (2), pp. 137–150, 2014.

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Noor Z Al Dahhan; John R Kirby; Donald C Brien; Douglas P Munoz

Eye movements and articulations during a letter naming speed task: Children with and without Dyslexia Journal Article

Journal of Learning Disabilities, 50 (3), pp. 275–285, 2017.

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Hani Alers; Judith A Redi; Ingrid Heynderickx

Quantifying the importance of preserving video quality in visually important regions at the expense of background content Journal Article

Signal Processing: Image Communication, 32 , pp. 69–80, 2015.

Abstract | Links | BibTeX

@article{Alers2015,
title = {Quantifying the importance of preserving video quality in visually important regions at the expense of background content},
author = {Hani Alers and Judith A Redi and Ingrid Heynderickx},
doi = {10.1016/j.image.2015.01.006},
year = {2015},
date = {2015-01-01},
journal = {Signal Processing: Image Communication},
volume = {32},
pages = {69--80},
publisher = {Elsevier},
abstract = {Advances in digital technology have allowed us to embed significant processing power in everyday video consumption devices. At the same time, we have placed high demands on the video content itself by continuing to increase spatial resolution while trying to limit the allocated file size and bandwidth as much as possible. The result is typically a trade-off between perceptual quality and fulfillment of technological limitations. To bring this trade-off to its optimum, it is necessary to understand better how people perceive video quality. In this work, we particularly focus on understanding how the spatial location of compression artifacts impacts visual quality perception, and specifically in relation with visual attention. In particular we investigate how changing the quality of the region of interest of a video affects its overall perceived quality, and we quantify the importance of the visual quality of the region of interest to the overall quality judgment. A three stage experiment was conducted where viewers were shown videos with different quality levels in different parts of the scene. By asking them to score the overall quality we found that the quality of the region of interest has 10 times more impact than the quality of the rest of the scene. These results are in line with similar effects observed in still images, yet in videos the relevance of the visual quality of the region of interest is twice as high than in images. The latter finding is directly relevant for the design of more accurate objective quality metrics for videos, that are based on the estimation of local distortion visibility.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Robert G Alexander; Gregory J Zelinsky

Visual similarity effects in categorical search Journal Article

Journal of Vision, 11 (8), pp. 1–15, 2011.

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