The Neural Oculomotor System in Strabismus

2019 ◽  
pp. 141-163
Author(s):  
Vallabh E. Das
Keyword(s):  
Oculomotor System

scholarly journals Model of the oculomotor system based on adaptive internal models

2020 ◽  
Vol 53 (2) ◽  
pp. 16430-16437
Author(s):  
Mireille E. Broucke
Keyword(s):  
Oculomotor System ◽  
Internal Models

scholarly journals Giving Subjects the Eye and Showing Them the Finger: Socio-Biological Cues and Saccade Generation in the Anti-Saccade Task

Perception ◽  
10.1068/p7085 ◽  
2012 ◽  
Vol 41 (2) ◽  
pp. 131-147 ◽  
Author(s):  
Nicola J Gregory ◽  
Timothy L Hodgson
Keyword(s):  
Opposite Direction ◽  
Reaction Times ◽  
Oculomotor System ◽  
Short Soas ◽  
Stimulus Onset ◽  
Saccade Direction ◽  
Saccade Task ◽  
Saccadic Reaction Times ◽  
Saccadic Responses ◽  
Gaze Cues

Pointing with the eyes or the finger occurs frequently in social interaction to indicate direction of attention and one's intentions. Research with a voluntary saccade task (where saccade direction is instructed by the colour of a fixation point) suggested that gaze cues automatically activate the oculomotor system, but non-biological cues, like arrows, do not. However, other work has failed to support the claim that gaze cues are special. In the current research we introduced biological and non-biological cues into the anti-saccade task, using a range of stimulus onset asynchronies (SOAs). The anti-saccade task recruits both top–down and bottom–up attentional mechanisms, as occurs in naturalistic saccadic behaviour. In experiment 1 gaze, but not arrows, facilitated saccadic reaction times (SRTs) in the opposite direction to the cues over all SOAs, whereas in experiment 2 directional word cues had no effect on saccades. In experiment 3 finger pointing cues caused reduced SRTs in the opposite direction to the cues at short SOAs. These findings suggest that biological cues automatically recruit the oculomotor system whereas non-biological cues do not. Furthermore, the anti-saccade task set appears to facilitate saccadic responses in the opposite direction to the cues.

Peripheral Facial Features Guiding Eye Movements and Reducing Fixational Variability

2021 ◽  
Author(s):  
Nicole X Han ◽  
Puneeth N. Chakravarthula ◽  
Miguel P. Eckstein
Keyword(s):  
Eye Movements ◽  
Spatial Configuration ◽  
Oculomotor System ◽  
Facial Features ◽  
Robust Solution ◽  
The Face ◽  
And Gender ◽  
Social Importance ◽  
Fixation Variability

Face processing is a fast and efficient process due to its evolutionary and social importance. A majority of people direct their first eye movement to a featureless point just below the eyes that maximizes accuracy in recognizing a person's identity and gender. Yet, the exact properties or features of the face that guide the first eye movements and reduce fixational variability are unknown. Here, we manipulated the presence of the facial features and the spatial configuration of features to investigate their effect on the location and variability of first and second fixations to peripherally presented faces. Results showed that observers can utilize the face outline, individual facial features, and feature spatial configuration to guide the first eye movements to their preferred point of fixation. The eyes have a preferential role in guiding the first eye movements and reducing fixation variability. Eliminating the eyes or altering their position had the greatest influence on the location and variability of fixations and resulted in the largest detriment to face identification performance. The other internal features (nose and mouth) also contribute to reducing fixation variability. A subsequent experiment measuring detection of single features showed that the eyes have the highest detectability (relative to other features) in the visual periphery providing a strong sensory signal to guide the oculomotor system. Together, the results suggest a flexible multiple-cue approach that might be a robust solution to cope with how the varying eccentricities in the real world influence the ability to resolve individual feature properties and the preferential role of the eyes.

Structure and electrical properties of eye muscles in cave- and surface-dwelling crayfishes

1980 ◽  
Vol 84 (1) ◽  
pp. 187-199
Author(s):  
D. Mellon ◽  
G. Lnenicka
Keyword(s):  
Input Resistance ◽  
Selective Advantage ◽  
Oculomotor System ◽  
Membrane Resistance ◽  
Muscle Fibres ◽  
Cross Sectional ◽  
Eye Muscles ◽  
Current Voltage ◽  
The Difference ◽  
Cave Dweller

The morphologies and passive electrical parameters of fibres in two eye muscles of a surface- and a cave-dwelling crayfish were compared. In the cave-dwelling form the muscles contained fewer fibres, of less diameter, and hence had a smaller cross-sectional area. Current-voltage relationships were similar in both species. Input resistance was higher in the cave-dweller, but the difference was not as great as would be expected on the basis of geometry alone. Accordingly, the specific membrane resistance of muscle fibres in the cave-dweller is 50–60% smaller than that in the surface-dweller. This may account partially for the observation that identified excitatory junctional potentials in muscles of cave- and surface dwellers have similar amplitudes. We conclude that a functional oculomotor system is maintained in cave-dwelling crayfish, and that this system confers some positive selective advantage.

Adaptability and Variability in the Oculomotor System

1997 ◽  
pp. 827-831
Author(s):  
David F. Scollan ◽  
Beau K. Nakamoto ◽  
Mark Shelhamer
Keyword(s):  
Oculomotor System

Corollary discharge provides accurate eye position information to the oculomotor system

Science ◽  
1983 ◽  
Vol 221 (4616) ◽  
pp. 1193-1195 ◽  
Author(s):  
B. Guthrie ◽  
J. Porter ◽  
D. Sparks
Keyword(s):  
Oculomotor System ◽  
Corollary Discharge ◽  
Eye Position ◽  
Position Information

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.

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