The Efference Copy Neurone

1971 ◽  
Vol 54 (2) ◽  
pp. 403-414
Author(s):  
J. R. JOHNSTONE ◽  
R. F. MARK
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Sensory Input ◽  
Efference Copy ◽  
The Other ◽  
Tonic Activity ◽  
Total Removal ◽  
Perceptual Stability ◽  
Direction Of Movement ◽  
Discharge Patterns

1. Neurones which fire at the same time as saccades are found in the tectal commissure of carp. They are unaffected by visual stimuli or by paralysis of eye muscles and so their activity is not directly related to sensory input. 2. Twenty-two units have been examined. They fire in bursts only during eye movements and only for a particular direction of movement, either eyes-left or eyes-right. They begin to fire a few milliseconds before eye movement begins, slowly at first, reach a maximum frequency of about 300 Hz, then slow again and stop after about 100 ms. 3. In two instances such units have been recorded simultaneously in paralysed fish with a tonically firing unit, presumably visual, which was suppressed during each burst. In one case the tonic activity after each burst was increased, in the other it was decreased. 4. We suggest they are efference copy neurones, responsible for perceptual stability during eye movements. Their possible function is discussed in detail. They are not tectal motoneurones because the same eye movements continue after total removal of the tectum. Neither are they dependent on sensory input resulting from eye movement because their discharge patterns are unaffected by darkness or paralysis.

Effects of Viewing Distance on the Responses of Vestibular Neurons to Combined Angular and Linear Vestibular Stimulation

1999 ◽  
Vol 81 (5) ◽  
pp. 2538-2557 ◽  
Author(s):  
Chiju Chen-Huang ◽  
Robert A. McCrea
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Vestibular Stimulation ◽  
The Other ◽  
Viewing Distance ◽  
Vestibuloocular Reflex ◽  
Horizontal Canal ◽  
Head Velocity ◽  
Vestibular Neurons ◽  
Axis Of Rotation

Effects of viewing distance on the responses of vestibular neurons to combined angular and linear vestibular stimulation. The firing behavior of 59 horizontal canal–related secondary vestibular neurons was studied in alert squirrel monkeys during the combined angular and linear vestibuloocular reflex (CVOR). The CVOR was evoked by positioning the animal’s head 20 cm in front of, or behind, the axis of rotation during whole body rotation (0.7, 1.9, and 4.0 Hz). The effect of viewing distance was studied by having the monkeys fixate small targets that were either near (10 cm) or far (1.3–1.7 m) from the eyes. Most units (50/59) were sensitive to eye movements and were monosynaptically activated after electrical stimulation of the vestibular nerve (51/56 tested). The responses of eye movement–related units were significantly affected by viewing distance. The viewing distance–related change in response gain of many eye-head-velocity and burst-position units was comparable with the change in eye movement gain. On the other hand, position-vestibular-pause units were approximately half as sensitive to changes in viewing distance as were eye movements. The sensitivity of units to the linear vestibuloocular reflex (LVOR) was estimated by subtraction of angular vestibuloocular reflex (AVOR)–related responses recorded with the head in the center of the axis of rotation from CVOR responses. During far target viewing, unit sensitivity to linear translation was small, but during near target viewing the firing rate of many units was strongly modulated. The LVOR responses and viewing distance–related LVOR responses of most units were nearly in phase with linear head velocity. The signals generated by secondary vestibular units during voluntary cancellation of the AVOR and CVOR were comparable. However, unit sensitivity to linear translation and angular rotation were not well correlated either during far or near target viewing. Unit LVOR responses were also not well correlated with their sensitivity to smooth pursuit eye movements or their sensitivity to viewing distance during the AVOR. On the other hand there was a significant correlation between static eye position sensitivity and sensitivity to viewing distance. We conclude that secondary horizontal canal–related vestibuloocular pathways are an important part of the premotor neural substrate that produces the LVOR. The otolith sensory signals that appear on these pathways have been spatially and temporally transformed to match the angular eye movement commands required to stabilize images at different distances. We suggest that this transformation may be performed by the circuits related to temporal integration of the LVOR.

Providing a human user artificial ability to control their eyes independently with various eye movement patterns

2012 ◽  
Vol 25 (0) ◽  
pp. 171-172
Author(s):  
Fumio Mizuno ◽  
Tomoaki Hayasaka ◽  
Takami Yamaguchi
Keyword(s):  
Eye Movements ◽  
Visual Perception ◽  
Control Systems ◽  
Eye Movement ◽  
Binocular Rivalry ◽  
Human Visual System ◽  
Visual Stimulation ◽  
The Other ◽  
Flexible Adaptation ◽  
Left And Right

Humans have the capability to flexibly adapt to visual stimulation, such as spatial inversion in which a person wears glasses that display images upside down for long periods of time (Ewert, 1930; Snyder and Pronko, 1952; Stratton, 1887). To investigate feasibility of extension of vision and the flexible adaptation of the human visual system with binocular rivalry, we developed a system that provides a human user with the artificial oculomotor ability to control their eyes independently for arbitrary directions, and we named the system Virtual Chameleon having to do with Chameleons (Mizuno et al., 2010, 2011). The successful users of the system were able to actively control visual axes by manipulating 3D sensors held by their both hands, to watch independent fields of view presented to the left and right eyes, and to look around as chameleons do. Although it was thought that those independent fields of view provided to the user were formed by eye movements control corresponding to pursuit movements on human, the system did not have control systems to perform saccadic movements and compensatory movements as numerous animals including human do. Fluctuations in dominance and suppression with binocular rivalry are irregular, but it is possible to bias these fluctuations by boosting the strength of one rival image over the other (Blake and Logothetis, 2002). It was assumed that visual stimuli induced by various eye movements affect predominance. Therefore, in this research, we focused on influenced of patterns of eye movements on visual perception with binocular rivalry, and implemented functions to produce saccadic movements in Virtual Chameleon.

Effects of Phosphor Persistence on Perception and the Control of Eye Movements

Perception ◽  
1989 ◽  
Vol 18 (2) ◽  
pp. 257-264 ◽  
Author(s):  
Catherine Neary ◽  
Arnold J Wilkins
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
The Other ◽  
Saccadic Suppression ◽  
Rapid Eye Movement ◽  
Physiological Basis ◽  
Cathode Ray Tube ◽  
Ghost Image ◽  
Corrective Saccades

When a rapid eye movement (saccade) is made across material displayed on cathode ray tube monitors with short-persistence phosphors, various perceptual phenomena occur. The phenomena do not occur when the monitor has a long-persistence phosphor. These phenomena were observed for certain spatial arrays, their possible physiological basis noted, and their effect on the control of eye movements examined. When the display consisted simply of two dots, and a saccade was made from one to the other, a transient ghost image was seen just beyond the destination target. When the display consisted of vertical lines, tilting and displacement of the lines occurred. The phenomena were more intrusive for the latter display and there was a significant increase in the number of corrective saccades. These results are interpreted in terms of the effects of fluctuating illumination (and hence phosphor persistence) on saccadic suppression.

Extraocular muscle proprioception functions in the control of ocular alignment and eye movement conjugacy

1994 ◽  
Vol 72 (2) ◽  
pp. 1028-1031 ◽  
Author(s):  
R. F. Lewis ◽  
D. S. Zee ◽  
B. M. Gaymard ◽  
B. L. Guthrie
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Extraocular Muscle ◽  
Efference Copy ◽  
Binocular Viewing ◽  
Error Signal ◽  
Muscle Proprioception ◽  
Adaptive Mechanisms ◽  
Before And After

1. The function of extraocular muscle proprioception in the control of eye movements is uncertain. We tested the hypothesis that proprioception contributes to the long-term regulation of ocular alignment and eye movement conjugacy. 2. Eye movements were recorded in monkeys with unilateral extraocular muscle palsies, before and after proprioceptive deafferentation of the paretic eye. Following deafferentation, ocular alignment and saccade conjugacy gradually worsened over several weeks. In contrast, disconjugate adaptation induced by habitual binocular viewing with a prism (disparity-mediated adaptation) occurred normally after deafferentation. 3. These results provide the first evidence that proprioception functions in the control of eye movements in primates, and indicate that proprioception contributes to the long-term adaptive mechanisms that regulate ocular alignment during fixation and saccades. The error signal used in this process may be derived from a mismatch between the efference copy and proprioceptive afference.

Eye Guidance in Reading: Fixation Locations within Words

Perception ◽  
1979 ◽  
Vol 8 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Keith Rayner
Keyword(s):  
Eye Movements ◽  
Cognitive Control ◽  
Eye Movement ◽  
The Other ◽  
Conditional Probabilities ◽  
Saccade Length ◽  
Fixation Locations ◽  
Cognitive Activities ◽  
The Right

Three broad categories of models of eye movement guidance in reading are described. According to one category, eye movements in reading are not under stimulus or cognitive control; the other two categories indicate that cognitive activities or stimulus characteristics are involved in eye guidance. In this study a number of descriptive analyses of eye movements in reading were carried out. These analyses dealt with fixation locations on letters within words of various lengths, conditional probabilities that a word will be fixated given that a prior word was or was not fixated, and average saccade length as a function of the length of the word to the right of the fixated word. The results of these analyses were supportive of models which suggest that determining where to look next while reading is made on a nonrandom basis.

scholarly journals The Role of Eye-Movements in Eye-Movement Desensitization and Reprocessing: Eye-Movements Lower the Number of Intrusive Thoughts of Negative Memories

2021 ◽  
Author(s):  
◽  
Gauranga Jeram Patel
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Traumatic Event ◽  
Intrusive Thoughts ◽  
Central Executive ◽  
Post Traumatic Stress ◽  
Autobiographical Memories ◽  
Direction Of Movement ◽  
Post Traumatic ◽  
Negative Memories

<p>Eye-Movement Desensitization and Reprocessing (EMDR) was developed as a treatment for Post-Traumatic Stress Disorder (PTSD), and involves the patient thinking about a traumatic event while simultaneously moving their eyes from side to side. Despite substantial support for the efficacy of EMDR questions remain regarding how eye-movements contribute to therapy. One explanation is that eye-movements tax a part of working memory known as the central executive; however, the exact mechanism involved is still unclear. Previous eye-movement research has focussed on self-ratings of vividness and emotionality of negative memories as the primary outcome measures. The focus of the current research was to examine the effect of eye-movements on the suppression of negative autobiographical memories in addition to vividness and emotionality. Non-clinical participants were asked to recall negative autobiographical memories and then verbally reported ratings of vividness and emotionality. In the eye-movement conditions, which varied by speed and direction of movement, eye-movements were stimulated using dots on a computer screen. Participants were then asked to avoid thinking of their memories, and intrusive thoughts were measured by pressing a computer key. Six experiments found that, overall, the effect of eye-movements on self-ratings was inconsistent, but that eye-movements reliably improved suppression of negative autobiographical memories. The findings also support the central executive explanation for the effectiveness of eye-movements in EMDR.</p>

scholarly journals The Role of Eye-Movements in Eye-Movement Desensitization and Reprocessing: Eye-Movements Lower the Number of Intrusive Thoughts of Negative Memories

2021 ◽  
Author(s):  
◽  
Gauranga Jeram Patel
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Traumatic Event ◽  
Intrusive Thoughts ◽  
Central Executive ◽  
Post Traumatic Stress ◽  
Autobiographical Memories ◽  
Direction Of Movement ◽  
Post Traumatic ◽  
Negative Memories

<p>Eye-Movement Desensitization and Reprocessing (EMDR) was developed as a treatment for Post-Traumatic Stress Disorder (PTSD), and involves the patient thinking about a traumatic event while simultaneously moving their eyes from side to side. Despite substantial support for the efficacy of EMDR questions remain regarding how eye-movements contribute to therapy. One explanation is that eye-movements tax a part of working memory known as the central executive; however, the exact mechanism involved is still unclear. Previous eye-movement research has focussed on self-ratings of vividness and emotionality of negative memories as the primary outcome measures. The focus of the current research was to examine the effect of eye-movements on the suppression of negative autobiographical memories in addition to vividness and emotionality. Non-clinical participants were asked to recall negative autobiographical memories and then verbally reported ratings of vividness and emotionality. In the eye-movement conditions, which varied by speed and direction of movement, eye-movements were stimulated using dots on a computer screen. Participants were then asked to avoid thinking of their memories, and intrusive thoughts were measured by pressing a computer key. Six experiments found that, overall, the effect of eye-movements on self-ratings was inconsistent, but that eye-movements reliably improved suppression of negative autobiographical memories. The findings also support the central executive explanation for the effectiveness of eye-movements in EMDR.</p>

Discharges of neurons in the dorsal paraflocculus of monkeys during eye movements and visual stimulation

1986 ◽  
Vol 56 (4) ◽  
pp. 1129-1146 ◽  
Author(s):  
H. Noda ◽  
A. Mikami
Keyword(s):  
Eye Movements ◽  
Slip Velocity ◽  
Visual Stimulation ◽  
The Other ◽  
Eye Position ◽  
Tonic Activity ◽  
Stimulus Movement ◽  
Retinal Slip ◽  
Position Sensitivity ◽  
P Cells

Extracellular recordings were obtained from 319 input units and 304 Purkinje cells (P-cells) in the dorsal paraflocculus of alert monkeys trained to fixate a visual target. They changed discharge rates with either eye movement, eye position, or visual stimulus movement. Of the 319 input units, recorded in the granular layer or white matter, most were mossy fibers (MFs), but 90 (28%) showed characteristic cellular spikes. The latter units were probably granular cells (p-GC). Of the 319 input units, 163 (51%) showed bursts with saccades (burst units) and 62 (19%) showed a prelude on the average 124 ms prior to the onset of saccade (long-lead burst units). Sixty-five (20%) had tonic activity related to eye position and also showed bursts with saccades (burst-tonic units), and the remaining 29 (9%) showed only tonic activity (tonic units). MFs and p-GCs showed no significant differences in the proportion of each type of unit or in their response properties. The majority of burst units (63%) were pan directional, whereas all long-lead burst units had directional selectivity. The preferred directions of long-lead burst, burst tonic, and directionally selective burst units were found in all four quadrants. Position-related activity was found in 48% of the burst-tonic and tonic units to be linearly related to eye position and to show position threshold. The other units also had position thresholds but their activity was not monotonically related to fixation position. Six climbing fibers (CFs), 32 input units (including 13 p-GC), and 8 P-cells showed cyclic responses during sinusoidal movements of a visual pattern. One class of MF units (57%) responded only to the direction, whereas the others responded to both the direction and retinal-slip velocity. Both CF and P-cell units responded to sinusoidal retinal-slip velocity. Of 67 input units, 23 showed cyclic modulation in firing during sinusoidal eye movements in the horizontal plane. Nineteen were burst-tonic and four were tonic units. They also showed position sensitivity. The phase of the cyclic responses tended to lag behind the eye velocity during low-frequency trackings. Of 237 P-cells, 163 (68.8%) discharged with saccades (burst P-cells), 42 (17.7%) paused with saccades (pause P-cells), and 32 (13.5%) discharged with saccades in one direction and paused in the other (burst-pause P-cells). Position sensitivity was found in 38 P-cells; 12 were burst, 5 were pause, and 10 were burst-pause P-cells. Eleven did not respond with saccades.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of Experience and Short-Term Practice on Drivers' Eye Movements and Errors in Simulated Dangerous Situations

1978 ◽  
Vol 47 (3) ◽  
pp. 767-776 ◽  
Author(s):  
John A. Allen ◽  
Stephen R. Schroeder ◽  
Patricia G. Ball
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Search Strategy ◽  
The Other ◽  
Short Term ◽  
Control Actions ◽  
Training Film ◽  
Relationship Of ◽  
The Relationship

Two groups of 10 subjects tracked a segment of the Aetna training film, Traffic Strategy, six times by manipulating the controls of an Aetna Drivo-Trainer station. One group was composed of licensed drivers, the other, nonlicensed. No significant differences were found with respect to: (1) use of the accelerator, (2) frequency of eye movements, (3) length of eye movements, (4) fixation errors, (5) driving errors, or (6) the relationship of control actions to driving errors. Differences were noted with respect to: (1) steering and braking, (2) the effects of practice on control actions and driving errors, and (3) the relationship of amplitude of eye movement to control actions and driving errors. The results are discussed in terms of possible differences in search strategy between experienced and inexperienced drivers.

Dynamic Circuitry for Updating Spatial Representations. II. Physiological Evidence for Interhemispheric Transfer in Area LIP of the Split-Brain Macaque

2005 ◽  
Vol 94 (5) ◽  
pp. 3249-3258 ◽  
Author(s):  
Laura M. Heiser ◽  
Rebecca A. Berman ◽  
Richard C. Saunders ◽  
Carol L. Colby
Keyword(s):  
Eye Movements ◽  
Visual Representations ◽  
The Other ◽  
Spatial Representations ◽  
Lateral Intraparietal Area ◽  
Split Brain ◽  
Perceptual Stability ◽  
Visual Hemifield ◽  
Principal Finding ◽  
The Brain

With each eye movement, a new image impinges on the retina, yet we do not notice any shift in visual perception. This perceptual stability indicates that the brain must be able to update visual representations to take our eye movements into account. Neurons in the lateral intraparietal area (LIP) update visual representations when the eyes move. The circuitry that supports these updated representations remains unknown, however. In this experiment, we asked whether the forebrain commissures are necessary for updating in area LIP when stimulus representations must be updated from one visual hemifield to the other. We addressed this question by recording from LIP neurons in split-brain monkeys during two conditions: stimulus traces were updated either across or within hemifields. Our expectation was that across-hemifield updating activity in LIP would be reduced or abolished after transection of the forebrain commissures. Our principal finding is that LIP neurons can update stimulus traces from one hemifield to the other even in the absence of the forebrain commissures. This finding provides the first evidence that representations in parietal cortex can be updated without the use of direct cortico-cortical links. The second main finding is that updating activity in LIP is modified in the split-brain monkey: across-hemifield signals are reduced in magnitude and delayed in onset compared with within-hemifield signals, which indicates that the pathways for across-hemifield updating are less effective in the absence of the forebrain commissures. Together these findings reveal a dynamic circuit that contributes to updating spatial representations.

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