scholarly journals Previewing a face in the periphery reduces the fN170: Combined EEG and eye-tracking suggests two stages of trans-saccadic predictive processes

2018 ◽  
Author(s):  
Christoph Huber-Huber ◽  
Antimo Buonocore ◽  
Clayton Hickey ◽  
David Melcher
Keyword(s):  
Eye Movements ◽  
Eye Tracking ◽  
Bayes Factor ◽  
Discrimination Performance ◽  
Saccadic Eye Movements ◽  
Visual Stability ◽  
Face Inversion Effect ◽  
Face Stimuli ◽  
Two Stages ◽  
Predictive Processes

AbstractThe world appears stable despite saccadic eye-movements. One possible explanation for this phenomenon is that the visual system predicts upcoming input across saccadic eye-movements, based on peripheral preview of the saccadic target. We tested this idea using concurrent electroencephalography (EEG) and eye-tracking. Participants made cued saccades to peripheral upright or inverted face stimuli that could change (invalid preview) or keep their orientation (valid preview) across the saccade. Experiment 1 demonstrated better discrimination performance and a reduced fixation-locked N170 (fN170) with valid than with invalid preview demonstrating integration of pre- and post-saccadic information. Moreover, the early fixation-locked EEG showed a preview face inversion effect suggesting that we perceive pre-saccadic input up to about 170 ms post fixation-onset, at least for face orientation. Experiment 2 replicated Experiment 1 and manipulated the proportion of valid and invalid trials (mostly valid versus mostly invalid, 66.6% to 33.3%) to test whether the preview effect reflected active expectations. A whole-scalp Bayes factor analysis provided evidence for no influence of proportion on the fN170 preview effect. Instead, before the saccade the preview face orientation effect declined earlier in the mostly invalid than in the mostly valid block suggesting some form of pre-saccadic expectations. We conclude that visual stability is achieved by two trans-saccadic integration processes: pre-saccadic prediction, reflected in the pre-saccadic proportion modulation, and early post-saccadic change-detection reflected in the fN170 preview effect.

scholarly journals A Fast and Effective System for Analysis of Optokinetic Waveforms with a Low-Cost Eye Tracking Device

Healthcare ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 10
Author(s):  
Chong-Bin Tsai ◽  
Wei-Yu Hung ◽  
Wei-Yen Hsu
Keyword(s):  
Eye Movements ◽  
Eye Tracking ◽  
Eye Movement ◽  
Low Cost ◽  
Saccadic Eye Movements ◽  
Slow Phase ◽  
Eye Tracker ◽  
Effective System ◽  
Tracking Device ◽  
Traditional Approaches

Optokinetic nystagmus (OKN) is an involuntary eye movement induced by motion of a large proportion of the visual field. It consists of a “slow phase (SP)” with eye movements in the same direction as the movement of the pattern and a “fast phase (FP)” with saccadic eye movements in the opposite direction. Study of OKN can reveal valuable information in ophthalmology, neurology and psychology. However, the current commercially available high-resolution and research-grade eye tracker is usually expensive. Methods & Results: We developed a novel fast and effective system combined with a low-cost eye tracking device to accurately quantitatively measure OKN eye movement. Conclusions: The experimental results indicate that the proposed method achieves fast and promising results in comparisons with several traditional approaches.

scholarly journals Impaired Inhibitory Control of Saccadic Eye Movements in Cervical Dystonia: An Eye‐Tracking Study

2021 ◽  
Author(s):  
Federico Carbone ◽  
Philipp Ellmerer ◽  
Marcel Ritter ◽  
Sabine Spielberger ◽  
Philipp Mahlknecht ◽  
...  
Keyword(s):  
Eye Movements ◽  
Eye Tracking ◽  
Inhibitory Control ◽  
Cervical Dystonia ◽  
Saccadic Eye Movements

Neuronal death of the cancellation theory?

1994 ◽  
Vol 17 (2) ◽  
pp. 274-275
Author(s):  
Claude Prablanc
Keyword(s):  
Eye Movements ◽  
Clinical Observation ◽  
Saccadic Eye Movements ◽  
Analytic Solutions ◽  
Visual Stability ◽  
Perceptual Stability ◽  
Stable Representation ◽  
The Subject ◽  
The Stability ◽  
The Brain

The question of how the brain can construct a stable representation of the external world despite eye movements is a very old one. If there have been some wrong statements of problems (such as the inverted retinal image), other statements are less naive and have led to analytic solutions possibly adopted by the brain to counteract the spurious effects of eye movements. Following the MacKay (1973) objections to the analytic view of perceptual stability, Bridgeman et al. claim that the idea that signals canceling the effects of saccadic eye movements are needed is also a misconception, as is the claim that stability and position encoding are two distinct problems. It must be remembered, however, that what made the theory of “cancellation” formulated by von Holst and Mittelstaedt (1950) so appealing was the clinical observation of perceptual instability following ocular paralysis. Following the concept of corollary discharge, the theory of efference copy had the advantage of simultaneously solving three problems: the stability of the visual world during the saccade, the same visual stability across saccades, and the visual constancy problem of allowing the subject to know where an object in space is.

scholarly journals Computerized Eye-Tracking Training Improves the Saccadic Eye Movements of Children with Attention-Deficit/Hyperactivity Disorder

2020 ◽  
Vol 10 (12) ◽  
pp. 1016
Author(s):  
Tsz Lok Lee ◽  
Michael K. Yeung ◽  
Sophia L. Sze ◽  
Agnes S. Chan
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Eye Movements ◽  
Eye Tracking ◽  
Attention Deficit ◽  
Saccadic Eye Movements ◽  
Saccade Latency ◽  
Pharmacological Intervention ◽  
Control Group ◽  
Children With Adhd ◽  
Hyperactivity Disorder

Abnormal saccadic eye movements, such as longer anti-saccade latency and lower pro-saccade accuracy, are common in children with attention-deficit/hyperactivity disorder (ADHD). The present study aimed to investigate the effectiveness of computerized eye-tracking training on improving saccadic eye movements in children with ADHD. Eighteen children with ADHD (mean age = 8.8 years, 10 males) were recruited and assigned to either the experimental (n = 9) or control group (n = 9). The experimental group underwent an accumulated 240 min of eye-tracking training within two weeks, whereas the control group engaged in web game playing for the same amount of time. Saccadic performances were assessed using the anti- and pro-saccade tasks before and after training. Compared to the baseline, only the children who underwent the eye-tracking training showed significant improvements in saccade latency and accuracy in the anti- and pro-saccade tasks, respectively. In contrast, the control group exhibited no significant changes. These preliminary findings support the use of eye-tracking training as a safe non-pharmacological intervention for improving the saccadic eye movements of children with ADHD.

scholarly journals Behavioural preview effect with faces

2020 ◽  
Author(s):  
Christoph Huber ◽  
David Melcher
Keyword(s):  
Mixed Model ◽  
Saccadic Eye Movements ◽  
Test Phase ◽  
Training Phase ◽  
Training Design ◽  
Visual Stability ◽  
Mixed Model Analysis ◽  
Subsequent Test ◽  
The World ◽  
Predictive Processes

The world around us appears stable and continuous despite saccadic eye movements. This apparent visual stability is achieved by trans-saccadic perception leading at the behavioural level to preview effects: Performance in processing a foveal stimulus is better if the stimulus remained unchanged (valid) compared to when it changed (invalid) during the saccade that brought it into focus. Trans-saccadic perception is known to predictively adapt to the statistics of the environment. Here, we asked whether the behavioural preview effect shows the same characteristics, employing a between-participants training design. Participants made saccades to faces which could change their orientation (upright/inverted) during the saccade. In addition, the post-saccadic face was slightly tilted and participants reported this tilt upon fixation. In a training phase, one group of participants conducted only invalid trials whereas another group conducted only valid trials. In a subsequent test phase with 50% valid and 50% invalid trials, we measured the preview effect. Invalid training eliminated the preview effect. With a mixed-model analysis, we could show how this training effect gradually declines in the course of the test phase. These results show that the behavioural preview effect adapts to the statistics of the environment suggesting that it results from predictive processes.

A theory of visual stability across saccadic eye movements

1994 ◽  
Vol 17 (2) ◽  
pp. 247-258 ◽  
Author(s):  
Bruce Bridgeman ◽  
A. H. C. Van der Heijden ◽  
Boris M. Velichkovsky
Keyword(s):  
Eye Movements ◽  
Saccadic Eye Movements ◽  
Visual Direction ◽  
Visual Stability ◽  
Perceptual Stability ◽  
Adequate Information ◽  
Psychological Evidence ◽  
Calibration Solution ◽  
Final Question ◽  
Direction Constancy

AbstractWe identify two aspects of the problem of maintaining perceptual stability despite an observer's eye movements. The first, visual direction constancy, is the (egocentric) stability of apparent positions of objects in the visual world relative to the perceiver. The second, visual position constancy, is the (exocentric) stability of positions of objects relative to each other. We analyze the constancy of visual direction despite saccadic eye movements.Three information sources have been proposed to enable the visual system to achieve stability: the structure of the visual field, proprioceptive inflow, and a copy of neural efference or outflow to the extraocular muscles. None of these sources by itself provides adequate information to achieve visual direction constancy; present evidence indicates that all three are used.Our final question concerns how information processing operations result in a stable world. The three traditionally suggested means have been elimination, translation, or evaluation. All are rejected. From a review of the physiological and psychological evidence we conclude that no subtraction, compensation, or evaluation need take place. The problem for which these solutions were developed turns out to be a false one. We propose a “calibration” solution: correct spatiotopic positions are calculated anew for each fixation. Inflow, outflow, and retinal sources are used in this calculation: saccadic suppression of displacement bridges the errors between these sources and the actual extent of movement.

Residual Vision in Multiple Retinal Locations within a Scotoma: Implications for Blindsight

1997 ◽  
Vol 9 (2) ◽  
pp. 191-202 ◽  
Author(s):  
R. W. Kentridge ◽  
C. A. Heywood ◽  
L. Weiskrantz
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Stimulus Display ◽  
Discrimination Performance ◽  
Saccadic Eye Movements ◽  
Lower Visual Field ◽  
Eye Tracker ◽  
Residual Vision ◽  
Fixation Stability ◽  
The Subject

There is an important new proposal that “blindsight”-the ability to detect and identify visual stimuli by forcedchoice guessing and in the absence of conscious awareness when they fall in blind regions of the visual field—is a function of residual “islands” of undamaged visual cortex. This stands in contrast to the widely accepted view that blindsight is exclusively a function of secondary visual pathways. According to the new view, residual vision in blindsight should be patchy. Thus, when apparently wide areas of residual vision in blindsight are found, these may be due to eye-movements that allow stimuli to pass over retinal locations corresponding to islands of sparing. We tested this hypothesis by examining the distribution of residual vision in blindsight when the effects of eye movements on the retinal location of stimuli were minimized. We report a series of experiments that examined twealternate forcedchoice discrimination in the blind field of the subject GY. Using a dual-Purkinje image eye-tracker we applied three methods of minimizing the effects of retinal slippage due to eye-movements on discrimination performance: fixation stability-dependent trials, software image stabilization, and post hoc rejection of trials in which saccadic eye-movements were detected. In the first experiment, GY's discrimination performance was significantly above chance in 8 of 15 locations tested. In the subsequent experiments the subject knew the location of the target in each block of trials, and this resulted in improvements to performance in a further three locations. Increasing the luminance of the stimulus display (while maintaining 95% target contrast), and increasing the temporal discriminability of the forced choice produced performance above chance in all but two of the locations tested. The consistent chance performance observed in two locations in the lower visual field nevertheless implies that GY's blindsight does not extend over the whole of his scotoma. Nevertheless, abolishing, or minimizing, the effects of eye-movements did not result in a loss of detection in all the widely separated regions tested, and we thus conclude that GY's blindsight cannot adequately be explained in terms of islands of spared vision. Islands may account for residual vision in scotomata in some patients, but cannot be a universal account of the phenomenon of blindsight.

Saccadic eye movements and visual stability

Nature ◽  
1978 ◽  
Vol 275 (5682) ◽  
pp. 766-768 ◽  
Author(s):  
P. LENNIE ◽  
A. SIDWELL
Keyword(s):  
Eye Movements ◽  
Saccadic Eye Movements ◽  
Visual Stability

Visual Attention and Manual Aiming: Evidence for Obligatory and Selective Spatial Coupling

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 34-34 ◽  
Author(s):  
H Deubel ◽  
W X Schneider ◽  
I Paprotta
Keyword(s):  
Eye Movements ◽  
Visual Attention ◽  
Visual Processing ◽  
Discrimination Performance ◽  
Saccadic Eye Movements ◽  
Visual Selective Attention ◽  
Saccade Target ◽  
Manual Aiming ◽  
Goal Object ◽  
Spatial Coupling

We recently demonstrated that visual attention before saccadic eye movements is focused on the saccade target, allowing for spatially selective object recognition (Deubel and Schneider Vision Research in press). Here we investigate the role of visual selective attention in the preparation of aiming hand movements. The interaction of visual attention and manual aiming was studied in a dual-task paradigm that required manual pointing to a target in combination with a letter discrimination task. Subjects were asked to keep fixation in the centre of a screen. Upon offset of a central cue, they had to aim, with unseen hand, to locations within horizontal letter strings left or right from the central fixation; movements were registered with a Polhemus FastTrack system. The ability to discriminate between the symbol “E” and its mirror image presented tachistoscopically within the surrounding distractors was taken as the measure of visual attention. The results reveal that discrimination performance is far superior when the discrimination stimulus is also the target for manual aiming; when discrimination stimulus and pointing target refer to different objects, performance deteriorates. We conclude that it is not possible to maintain attention on a stimulus while directing a manual movement to a spatially separate object. Rather, our results argue for an obligatory and selective coupling of visual attention and movement programming, just as found for saccadic eye movements. This is consistent with a model of visual attention (proposed by Schneider) in which a unitary attention mechanism selects a goal object for visual processing, and simultaneously provides the information necessary for goal-directed motor action such as saccades, pointing, and grasping.

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