The role of fixational eye movements in visual perception

2004 ◽  
Vol 5 (3) ◽  
pp. 229-240 ◽  
Author(s):  
Susana Martinez-Conde ◽  
Stephen L. Macknik ◽  
David H. Hubel
2007 ◽  
Vol 98 (3) ◽  
pp. 1380-1391 ◽  
Author(s):  
Ronen Segev ◽  
Elad Schneidman ◽  
Joe Goodhouse ◽  
Michael J. Berry

The concerted action of saccades and fixational eye movements are crucial for seeing stationary objects in the visual world. We studied how these eye movements contribute to retinal coding of visual information using the archer fish as a model system. We quantified the animal's ability to distinguish among objects of different sizes and measured its eye movements. We recorded from populations of retinal ganglion cells with a multielectrode array, while presenting visual stimuli matched to the behavioral task. We found that the beginning of fixation, namely the time immediately after the saccade, provided the most visual information about object size, with fixational eye movements, which consist of tremor and drift in the archer fish, yielding only a minor contribution. A simple decoder that combined information from ≤15 ganglion cells could account for the behavior. Our results support the view that saccades impose not just difficulties for the visual system, but also an opportunity for the retina to encode high quality “snapshots” of the environment.


2015 ◽  
Vol 151 ◽  
pp. 78-84 ◽  
Author(s):  
Andrés Olmedo-Payá ◽  
Antonio Martínez-Álvarez ◽  
Sergio Cuenca-Asensi ◽  
J.M. Ferrández ◽  
E. Fernández

2018 ◽  
Author(s):  
Rachel N. Denison ◽  
Shlomit Yuval-Greenberg ◽  
Marisa Carrasco

AbstractOur visual input is constantly changing, but not all moments are equally relevant. Temporal attention, the prioritization of visual information at specific points in time, increases perceptual sensitivity at behaviorally relevant times. The dynamic processes underlying this increase are unclear. During fixation, humans make small eye movements called microsaccades, and inhibiting microsaccades improves perception of brief stimuli. Here we asked whether temporal attention changes the pattern of microsaccades in anticipation of brief stimuli. Human observers (female and male) judged brief stimuli presented within a short sequence. They were given either an informative precue to attend to one of the stimuli, which was likely to be probed, or an uninformative (neutral) precue. We found strong microsaccadic inhibition before the stimulus sequence, likely due to its predictable onset. Critically, this anticipatory inhibition was stronger when the first target in the sequence (T1) was precued (task-relevant) than when the precue was uninformative. Moreover, the timing of the last microsaccade before T1 and the first microsaccade after T1 shifted, such that both occurred earlier when T1 was precued than when the precue was uninformative. Finally, the timing of the nearest pre- and post-T1 microsaccades affected task performance. Directing voluntary temporal attention therefore impacts microsaccades, helping to stabilize fixation at the most relevant moments, over and above the effect of predictability. Just as saccading to a relevant stimulus can be an overt correlate of the allocation of spatial attention, precisely timed gaze stabilization can be an overt correlate of the allocation of temporal attention.Significance statementWe pay attention at moments in time when a relevant event is likely to occur. Such temporal attention improves our visual perception, but how it does so is not well understood. Here we discovered a new behavioral correlate of voluntary, or goal-directed, temporal attention. We found that the pattern of small fixational eye movements called microsaccades changes around behaviorally relevant moments in a way that stabilizes the position of the eyes. Microsaccades during a brief visual stimulus can impair perception of that stimulus. Therefore, such fixation stabilization may contribute to the improvement of visual perception at attended times. This link suggests that in addition to cortical areas, subcortical areas mediating eye movements may be recruited with temporal attention.


2019 ◽  
Author(s):  
Beren Millidge

Fixational eye movements are ubiquitous and have a large impact on visual perception. Although their physical characteristics and, to some extent, neural underpinnings are well documented, their function, with the exception of preventing visual fading, remains poorly understood. In this paper, we propose that the visual system might utilize the relatively large number of similar slightly jittered images produced by fixational eye movements to help learn robust and spatially invariant representations as a form of neural data augmentation. Additionally, we form a link between effects such as retinal stabilization and predictive processing theory, and argue that they may be best explained under such a paradigm.


Ophthalmology ◽  
2018 ◽  
pp. 98-114
Author(s):  
Anwesha Banerjee ◽  
Ankita Mazumder ◽  
Poulami Ghosh ◽  
D. N. Tibarewala

We the human beings are blessed by the nature to become well competent for performing highly precise and copious visual processes with how ever a restricted field of view. Howbeit, this process of visual perception is, to a great extent, controlled by the saccades or more commonly the eye movements. The positioning and accommodation of eyes allows an image to be placed (or fixed) in the fovea centralis of the eyes but although we do so to fix our gaze at a particular object, our eyes continuously move. Even though these fixational eye movements includes magnitude that should make them visible to us yet we remain oblivious to them. Microsacades, drifts and tremors that occurs frequently during fixational eye movements, contribute largely to the visual perception. We use saccades several times per second to move the fovea between points of interest and build an understanding of our visual environment.


2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0016
Author(s):  
Prem Kumar Thirunagari ◽  
Nancy Phu ◽  
David Tramutolo ◽  
Hector Rieiro ◽  
Tanya Polec ◽  
...  

Background: Oculomotor and visual processing deficits occur commonly after brain injury in young athletes. A subset of these concussed athletes do experience prolonged recoveries or PPCS with ongoing oculomotor deficits and visual symptoms. There have been limited studies conducted to determine the significance of oculomotor tracking (OMT) testing in the pediatric population, and even less investigating the role of microsaccades. Hence, investigations on microsaccades(MS), physiological adjustive micro eye movements critical in visual processing and central/peripheral visual integration, may provide insight on the role of visual dysfunction in PPCS course, prognosis, and management. Purpose: The purpose of this study is to identify possible MS rate trends and differences between early and late stage PPCS pediatric patients. Methods: A retrospective cohort study of 41 pediatric patients with PPCS or symptoms greater than one month from injury. Data was collected from 7/1/2018 to 12/1/2019 and the age group ranged from 8 to 21 years. For each participant, using the OMT device we measured the number of saccades generated, the size and speed of the microsaccades, the area covered and the ratio of vertical-to-horizontal direction component of the fixational eye movements, using a 250 Hz video-eye tracker mounted inside a HTC Vive VR headset. Participants were instructed to fixate on a central dot for 140 seconds, in 20-second intervals. Patients were classified into early or late stages of PPCS (early stage: 1-6 months; late stage: >6 months) to compare MS rate between stages. Exclusion criteria included history of visual disorders, learning disorders, seizure disorder, or intracranial hemorrhage. Results: 27 patients were in the early stage while 14 patients were in the late stage. The early stage group had a mean MS rate of 125 beats/min while the late stage group had a mean MS rate of 116 beats/min. A two sample t-test assuming no difference between early and late stage patients resulted in a p value of 0.51. Conclusion: There is a potential trend in declining MS numbers with progressive PPCS stage. Although the t-test didn’t show statistical significance, this could be due to the small sample size of our study. Future studies are needed to validate this initial finding and to identify the significance of microsaccade patterns in concussion prognosis and management. [Figure: see text]


2021 ◽  
Author(s):  
Jacob L Yates ◽  
Shanna H Coop ◽  
Gabriel H Sarch ◽  
Ruei-Jr Wu ◽  
Daniel A Butts ◽  
...  

Virtually all vision studies use a fixation point to stabilize gaze, rendering stimuli on video screens fixed to retinal coordinates. This approach requires trained subjects, is limited by the accuracy of fixational eye movements, and ignores the role of eye movements in shaping visual input. To overcome these limitations, we developed a suite of hardware and software tools to study vision during natural behavior in untrained subjects. We show this approach recovers receptive fields and tuning properties of visual neurons from multiple cortical areas of marmoset monkeys. Combined with high-precision eye-tracking, it achieves sufficient resolution to recover the receptive fields of foveal V1 neurons. These findings demonstrate the power of this approach for characterizing neural response while simultaneously studying the dynamics of natural behavior.


Author(s):  
Maria I. Kiose

The article discusses the role of the age factor in the readers’ comprehension of stylistically heterogeneous texts, here the text fragments containing figurative noun groups of salient and non-salient character. The salience effects on eye movement and default responses are studied in the oculographic experiment where the secondary school children had to read the sentences displaying figurativeness. The earlier detected statistically significant corpus salience indices of referential, linguistic and discourse parameters in figurativeness construal get verified experimentally. In accordance with the Graded Salience and Defaultness hypotheses I assumed that the interpretation of figurative noun groups of varied referential, linguistic and discourse salience will require different cognitive effort in terms of both eye movement reactions and default inferences. Several eye-tracking experiments with adult participants sufficed to prove the dependency, however, the results obtained with children did not support the Salience hypothesis in the part of visual perception. The eye movements of children facing figurative noun groups did not show steady correlation patterns with the salience effects of these groups, whereas the default interpretations correlated strongly with referential, linguistic, and discourse salience. The results show evidence in favor of Mixed-Effects Model of interpretation


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Hao Wang ◽  
Sheila Gillard Crewther ◽  
Zheng Qin Yin

Strabismic amblyopia “blunt vision” is a developmental anomaly that affects binocular vision and results in lowered visual acuity. Strabismus is a term for a misalignment of the visual axes and is usually characterized by impaired ability of the strabismic eye to take up fixation. Such impaired fixation is usually a function of the temporally and spatially impaired binocular eye movements that normally underlie binocular shifts in visual attention. In this review, we discuss how abnormal eye movement function in children with misaligned eyes influences the development of normal binocular visual attention and results in deficits in visual function such as depth perception. We also discuss how eye movement function deficits in adult amblyopia patients can also lead to other abnormalities in visual perception. Finally, we examine how the nonamblyopic eye of an amblyope is also affected in strabismic amblyopia.


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