scholarly journals Pardon the interruption: saccadic inhibition enables the rapid deployment of alternate oculomotor plans

2018 ◽  
Author(s):  
Emilio Salinas ◽  
Terrence R. Stanford
Keyword(s):  
Eye Movement ◽  
Visual Information ◽  
Oculomotor System ◽  
Sudden Onset ◽  
Physiological Data ◽  
Alternative Plan ◽  
New Information ◽  
Saccadic Inhibition ◽  
Simulation Results ◽  
Rapid Deployment

Diverse psychophysical and neurophysiological results show that oculomotor networks are continuously active, such that plans for making the next eye movement are always ongoing. So, when new visual information arrives unexpectedly, how are those plans affected? At what point can the new information start guiding an eye movement, and how? Here, based on modeling and simulation results, we make two observations that are relevant to these questions. First, we note that many experiments, including those investigating the phenomenon known as “saccadic inhibition,” are consistent with the idea that sudden-onset stimuli briefly interrupt the gradual rise in neural activity associated with the preparation of an impending saccade. And second, we show that this stimulus-driven interruption is functionally adaptive, but only if perception is fast. In that case, putting on hold an ongoing saccade plan toward location A allows the oculomotor system to initiate a concurrent, alternative plan toward location B (where a stimulus just appeared), deliberate (briefly) on the priority of each target, and determine which plan should continue. Based on physiological data, we estimate that the actual advantage of this strategy, relative to one in which any plan once initiated must be completed, is of several tens of milliseconds.

Distributed Parallel Processing in the Vestibulo-Oculomotor System

1989 ◽  
Vol 1 (2) ◽  
pp. 230-241 ◽  
Author(s):  
Thomas J. Anastasio ◽  
David A. Robinson
Keyword(s):  
Eye Movement ◽  
Block Diagram ◽  
Vestibular Nucleus ◽  
Movement Control ◽  
Theoretical Models ◽  
Oculomotor System ◽  
Physiological Data ◽  
Neural Network Learning ◽  
Oculomotor Behavior ◽  
Distributed Models

The mechanisms of eye-movement control are among the best understood in motor neurophysiology. Detailed anatomical and physiological data have paved the way for theoretical models that have unified existing knowledge and suggested further experiments. These models have generally taken the form of black-box diagrams (for example, Robinson 1981) representing the flow of hypothetical signals between idealized signal-processing blocks. They approximate overall oculomotor behavior but indicate little about how real eye-movement signals would be carried and processed by real neural networks. Neurons that combine and transmit oculomotor signals, such as those in the vestibular nucleus (VN), actually do so in a diverse, seemingly random way that would be impossible to predict from a block diagram. The purpose of this study is to use a neural-network learning scheme (Rumelhart et al. 1986) to construct parallel, distributed models of the vestibulo-oculomotor system that simulate the diversity of responses recorded experimentally from VN neurons.

The Remarkable Vestibuloocular Reflex

Physiology ◽  
1987 ◽  
Vol 2 (3) ◽  
pp. 85-89
Author(s):  
GM Jones
Keyword(s):  
Automatic Control ◽  
Eye Movement ◽  
Visual Information ◽  
Control Mechanism ◽  
Eye Position ◽  
Vestibuloocular Reflex ◽  
New Information ◽  
Plastic Changes

The amazing ability of the eye to remain fixed on a target during rapid movements of the head depends on the familiar automatic control mechanism known as the vestibuloocular reflex. This article presents new information about this reflex in the control of eye movement and the stabilization of eye position. The reflex is found to be highly adaptive, including the curious recent finding that imaginary visual information can initiate plastic changes.

scholarly journals Refixation control in free viewing: a specialized mechanism divulged by eye-movement-related brain activity

2018 ◽  
Vol 120 (5) ◽  
pp. 2311-2324 ◽  
Author(s):  
Andrey R. Nikolaev ◽  
Radha Nila Meghanathan ◽  
Cees van Leeuwen
Keyword(s):  
Eye Movement ◽  
Visual Information ◽  
Direct Evidence ◽  
Search Task ◽  
Visual Search Task ◽  
Brain Activity ◽  
Movement Control ◽  
Planning Stage ◽  
Eye Fixations ◽  
Free Viewing

In free viewing, the eyes return to previously visited locations rather frequently, even though the attentional and memory-related processes controlling eye-movement show a strong antirefixation bias. To overcome this bias, a special refixation triggering mechanism may have to be recruited. We probed the neural evidence for such a mechanism by combining eye tracking with EEG recording. A distinctive signal associated with refixation planning was observed in the EEG during the presaccadic interval: the presaccadic potential was reduced in amplitude before a refixation compared with normal fixations. The result offers direct evidence for a special refixation mechanism that operates in the saccade planning stage of eye movement control. Once the eyes have landed on the revisited location, acquisition of visual information proceeds indistinguishably from ordinary fixations. NEW & NOTEWORTHY A substantial proportion of eye fixations in human natural viewing behavior are revisits of recently visited locations, i.e., refixations. Our recently developed methods enabled us to study refixations in a free viewing visual search task, using combined eye movement and EEG recording. We identified in the EEG a distinctive refixation-related signal, signifying a control mechanism specific to refixations as opposed to ordinary eye fixations.

scholarly journals Conscious and unconscious memory differentially impact attention: Eye movements, visual search, and recognition processes

2019 ◽  
Author(s):  
Michelle Ramey ◽  
Andrew P. Yonelinas ◽  
John M. Henderson
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Eye Movement ◽  
Visual Information ◽  
Subjective Memory ◽  
Conscious Recollection ◽  
Memory Awareness ◽  
Efficient Extraction ◽  
Subjective Reports ◽  
Unconscious Memory

A hotly debated question is whether memory influences attention through conscious or unconscious processes. To address this controversy, we measured eye movements while participants searched repeated real-world scenes for embedded targets, and we assessed memory for each scene using confidence-based methods to isolate different states of subjective memory awareness. We found that memory-informed eye movements during visual search were predicted both by conscious recollection, which led to a highly precise first eye movement toward the remembered location, and by unconscious memory, which increased search efficiency by gradually directing the eyes toward the target throughout the search trial. In contrast, these eye movement measures were not influenced by familiarity-based memory (i.e., changes in subjective reports of memory strength). The results indicate that conscious recollection and unconscious memory can each play distinct and complementary roles in guiding attention to facilitate efficient extraction of visual information.

scholarly journals Transfer Entropy Based Causality From Head Motion To Eye Movement

2021 ◽  
Author(s):  
Zezhong Lv ◽  
Qing Xu ◽  
Klaus Schoeffmann ◽  
Simon Parkinson
Keyword(s):  
Eye Movement ◽  
Information Acquisition ◽  
Visual Information ◽  
Transfer Entropy ◽  
Movement Behavior ◽  
Head Motion ◽  
Human Beings ◽  
Sensorimotor Activity ◽  
Set Up ◽  
Psychophysical Studies

AbstractEye movement behavior, which provides the visual information acquisition and processing, plays an important role in performing sensorimotor tasks, such as driving, by human beings in everyday life. In the procedure of performing sensorimotor tasks, eye movement is contributed through a specific coordination of head and eye in gaze changes, with head motions preceding eye movements. Notably we believe that this coordination in essence indicates a kind of causality. In this paper, we investigate transfer entropy to set up a quantity for measuring an unidirectional causality from head motion to eye movement. A normalized version of the proposed measure, demonstrated by virtual reality based psychophysical studies, behaves very well as a proxy of driving performance, suggesting that quantitative exploitation of coordination of head and eye may be an effective behaviometric of sensorimotor activity.

scholarly journals Eye Movement Abnormalities in Amyotrophic Lateral Sclerosis

2021 ◽  
Author(s):  
Xintong Guo ◽  
Xiaoxuan Liu ◽  
Shan Ye ◽  
Xiangyi Liu ◽  
Xu Yang ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Eye Movement ◽  
Smooth Pursuit ◽  
Oculomotor System ◽  
Control Group ◽  
Clinical Markers ◽  
Square Wave ◽  
Movement Parameters ◽  
Als Patients ◽  
Lateral Sclerosis

Abstract Background and Purpose It is generally believed that eye movements are completely spared in amyotrophic lateral sclerosis (ALS). Although a series of eye movement abnormalities has been recognized in recent years, the findings are highly controversial, and the corresponding pattern has not yet been established. Furthermore, bulbar disabilities should be considered in relation to eye movement abnormalities. The present study aimed to determine whether eye movement abnormalities are present in ALS and, if so, to investigate their characteristics and their association with bulbar disability in ALS patients. Methods Patients with clinically definite, probable or laboratory-supported probable ALS (n=60) and a control group composed of their caregivers (n=30) underwent clinical assessments and standardized evaluations of the oculomotor system using videonystagmography. The gaze test, reflexive saccade test and smooth pursuit test were administered to all subjects. Results Eye movement abnormalities such as square-wave jerks, abnormal cogwheeling during smooth pursuit, and saccade hypometria were observed in ALS patients. Square-wave jerks (p<0.001) and abnormal cogwheeling during smooth pursuit (p=0.001) were more frequently observed in ALS patients than in the control subjects. In subgroup analyses, square-wave jerks (p=0.004) and abnormal cogwheeling during smooth pursuit (p=0.031) were found to be more common in ALS patients with bulbar involvement (n=44) than in those without bulbar involvement (n=16). There were no significant differences in the investigated eye movement parameters between bulbar-onset (n=12) and spinal-onset patients (n=48). Conclusion ALS patients showed a range of eye movement abnormalities, affecting mainly the ocular fixation and smooth pursuit systems. These abnormalities were observed more common in the ALS patients with bulbar involvement. Our pioneering study indicates that the region of involvement could better indicate the pathophysiological essence of the abnormalities than the type of onset pattern in ALS. Eye movement abnormalities may be potential clinical markers for objectively evaluating upper brainstem or supratentorial cerebral lesion neurodegeneration in ALS.

scholarly journals Eye movement evaluation in Multiple Sclerosis and Parkinson’s Disease using a Standardized Oculomotor and Neuro-ophthalmic Disorder Assessment (SONDA)

2020 ◽  
Author(s):  
Alessandro Grillini ◽  
Remco J. Renken ◽  
Anne C. L. Vrijling ◽  
Joost Heutink ◽  
Frans W. Cornelissen
Keyword(s):  
Multiple Sclerosis ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Standardized Tests ◽  
Eye Movement ◽  
Oculomotor System ◽  
Oculomotor Behavior ◽  
Non Invasive ◽  
Spatio Temporal ◽  
Pursuit Gain

AbstractEvaluating the state of the oculomotor system of a patient is one of the fundamental tests done in neuro-ophthalmology. However, up to date, very few quantitative standardized tests of eye movements quality exist, limiting this assessment to confrontational tests reliant on subjective interpretation. Furthermore, quantitative tests relying on eye movement properties such as pursuit gain and saccade dynamics are often insufficient to capture the complexity of the underlying disorders and are often (too) long and tiring. In this study, we present SONDA (Standardised Oculomotor and Neurological Disorder Assessment): this test is based on analyzing eye tracking recorded during a short and intuitive continuous tracking task. We tested patients affected by Multiple Sclerosis (MS) and Parkinson’s Disease (PD) and find that: (1) the saccadic dynamics of the main sequence alone are not sufficient to separate patients from healthy controls; (2) the combination of spatio-temporal and statistical properties of saccades and saccadic dynamics enables an identification of oculomotor abnormalities in both MS and PD patients. We conclude that SONDA constitutes a powerful screening tool that allows an in-depth evaluation of (deviant) oculomotor behavior in a few minutes of non-invasive testing.

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