scholarly journals Predicting rhesus monkey eye movements during natural-image search

2017 ◽  
Vol 17 (3) ◽  
pp. 12 ◽  
Author(s):  
Mark A. Segraves ◽  
Emory Kuo ◽  
Sara Caddigan ◽  
Emily A. Berthiaume ◽  
Konrad P. Kording
Keyword(s):  
Eye Movements ◽  
Rhesus Monkey ◽  
Natural Image ◽  
Image Search

Modulation of Mean Eye Position during Vestibular Induced Eye Movements of the Rhesus Monkey

1984 ◽  
Vol 97 (5-6) ◽  
pp. 627-632 ◽  
Author(s):  
J. M. Furman ◽  
D. P. O'leary ◽  
J. W. Wolfe
Keyword(s):  
Eye Movements ◽  
Rhesus Monkey ◽  
Eye Position

scholarly journals Contrast sensitivity, V1 neural activity, and natural vision

2017 ◽  
Vol 117 (2) ◽  
pp. 492-508 ◽  
Author(s):  
James E. Niemeyer ◽  
Michael A. Paradiso
Keyword(s):  
Eye Movements ◽  
Contrast Sensitivity ◽  
Visual Processing ◽  
Brain Area ◽  
Saccadic Eye Movements ◽  
Visual Sensitivity ◽  
Natural Image ◽  
Spatial Frequencies ◽  
Natural Vision ◽  
Common Laboratory

Contrast sensitivity is fundamental to natural visual processing and an important tool for characterizing both visual function and clinical disorders. We simultaneously measured contrast sensitivity and neural contrast response functions and compared measurements in common laboratory conditions with naturalistic conditions. In typical experiments, a subject holds fixation and a stimulus is flashed on, whereas in natural vision, saccades bring stimuli into view. Motivated by our previous V1 findings, we tested the hypothesis that perceptual contrast sensitivity is lower in natural vision and that this effect is associated with corresponding changes in V1 activity. We found that contrast sensitivity and V1 activity are correlated and that the relationship is similar in laboratory and naturalistic paradigms. However, in the more natural situation, contrast sensitivity is reduced up to 25% compared with that in a standard fixation paradigm, particularly at lower spatial frequencies, and this effect correlates with significant reductions in V1 responses. Our data suggest that these reductions in natural vision result from fast adaptation on one fixation that lowers the response on a subsequent fixation. This is the first demonstration of rapid, natural-image adaptation that carries across saccades, a process that appears to constantly influence visual sensitivity in natural vision. NEW & NOTEWORTHY Visual sensitivity and activity in brain area V1 were studied in a paradigm that included saccadic eye movements and natural visual input. V1 responses and contrast sensitivity were significantly reduced compared with results in common laboratory paradigms. The parallel neural and perceptual effects of eye movements and stimulus complexity appear to be due to a form of rapid adaptation that carries across saccades.

scholarly journals Activity of Cells in the Deeper Layers of the Superior Colliculus of the Rhesus Monkey: Evidence for a Gaze Displacement Command

1997 ◽  
Vol 78 (3) ◽  
pp. 1669-1690 ◽  
Author(s):  
Edward G. Freedman ◽  
David L. Sparks
Keyword(s):  
Eye Movements ◽  
Rhesus Monkey ◽  
Superior Colliculus ◽  
Single Cells ◽  
Head Movements ◽  
Gaze Shifts ◽  
Unit Recording ◽  
The Gaze ◽  
Head Displacement ◽  
Separate Channel

Freedman, Edward G. and David L. Sparks. Activity of cells in the deeper layers of the superior colliculus of the rhesus monkey: evidence for a gaze displacement command. J. Neurophysiol. 78: 1669–1690, 1997. When the head is free to move, microstimulation of the primate superior colliculus (SC) evokes coordinated movements of the eyes and head. The similarity between these stimulation-induced movements and visually guided movements indicates that the SC of the primate is involved in redirecting the line of sight (gaze). To determine how movement commands are represented by individual collicular neurons, we recorded the activity of single cells in the deeper layers of the superior colliculus of the rhesus monkey during coordinated eye-head gaze shifts. Two alternative hypotheses were tested. The “separate channel” hypothesis states that two displacement commands are generated by the SC: one signal specifying the amplitude and direction of eye movements and a second signal specifying the amplitude and direction of head movements. Alternatively, a single gaze displacement command could be generated by the SC (“gaze displacement” hypothesis). The activity of collicular neurons was examined during three behavioral dissociations of gaze, eye, and head movement amplitude and direction (metrics). Subsets of trials were selected in which the amplitude and direction of either gaze shifts or eye movements or head movements were relatively constant but the metrics of the other two varied over wide ranges. Under these conditions, the separate channel and gaze displacement hypotheses make differential predictions about the patterns of SC activity. We tested these differential predictions by comparing observed patterns with predicted patterns of neuronal activity. We obtained data consistent with the predictions of the gaze displacement hypothesis. The predictions of the separate channel hypothesis were not confirmed. Thus microstimulation data, single-unit recording data, and behavioral data are all consistent with the gaze displacement hypothesis of collicular function—the hypothesis that a gaze displacement signal is derived from the locus of activity within the motor map of the SC and subsequently is decomposed into separate eye and head displacement signals downstream from the colliculus.

scholarly journals Improvement of natural image search engines results by emotional filtering

2016 ◽  
Vol 3 (6) ◽  
pp. 151164 ◽  
Author(s):  
Patrice Denis ◽  
Vincent Courboulay ◽  
Arnaud Revel ◽  
Syntyche Gbèhounou ◽  
François Lecellier ◽  
...  
Keyword(s):  
Search Engines ◽  
Natural Image ◽  
Image Search

scholarly journals Slow–fast control of eye movements: an instance of Zeeman’s model for an action

2020 ◽  
Vol 114 (4-5) ◽  
pp. 519-532
Author(s):  
Richard A. Clement ◽  
Ozgur E. Akman
Keyword(s):  
Eye Movements ◽  
Rhesus Monkey ◽  
Model Equation ◽  
Oculomotor System ◽  
State Space Reconstruction ◽  
Model Predictions ◽  
Motor Actions ◽  
Fast Control ◽  
Omnipause Neurons ◽  
Velocity Command

Abstract The rapid eye movements (saccades) used to transfer gaze between targets are examples of an action. The behaviour of saccades matches that of the slow–fast model of actions originally proposed by Zeeman. Here, we extend Zeeman’s model by incorporating an accumulator that represents the increase in certainty of the presence of a target, together with an integrator that converts a velocity command to a position command. The saccadic behaviour of several foveate species, including human, rhesus monkey and mouse, is replicated by the augmented model. Predictions of the linear stability of the saccadic system close to equilibrium are made, and it is shown that these could be tested by applying state-space reconstruction techniques to neurophysiological recordings. Moreover, each model equation describes behaviour that can be matched to specific classes of neurons found throughout the oculomotor system, and the implication of the model is that build-up, burst and omnipause neurons are found throughout the oculomotor pathway because they constitute the simplest circuit that can produce the motor commands required to specify the trajectories of motor actions.

Participation of prefrontal neurons in the preparation of visually guided eye movements in the rhesus monkey

1989 ◽  
Vol 61 (5) ◽  
pp. 1064-1084 ◽  
Author(s):  
R. A. Boch ◽  
M. E. Goldberg
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Receptive Field ◽  
Rhesus Monkey ◽  
Rhesus Monkeys ◽  
Peripheral Stimulus ◽  
Visual Response ◽  
Visually Guided ◽  
Saccade Task ◽  
Stimulus Shape

1. We recorded from 257 neurons in the banks of the posterior third of the principal sulcus of two rhesus monkeys trained to look at a fixation point and make saccades to stimuli in the visual periphery. Sixty-six percent (220/257) discharged or were suppressed in association with one or more aspects of the tasks we used. 2. Fifty-eight percent (151/257) of the neurons responded to the appearance of a spot of light in some part of the contralateral visual field. Cells did not seem to have absolute requirements for stimulus shape, size, or direction of motion. 3. Thirty-six percent (29/79) of visually responsive neurons tested quantitatively gave an enhanced response to the stimulus in the receptive field when the monkey had to make a saccade to the stimulus when its appearance was synchronous with the disappearance of the fixation point (synchron task). Twenty-nine percent (19/57) of the neurons gave an enhanced response to the stimulus when the monkey had to make a saccade to the stimulus some time after it appeared (delayed-saccade task). In general, enhancement in the synchron task correlated well with enhancement in the delayed-saccade task. 4. Enhancement was spatially specific. It did not occur when the monkey made a saccade to a stimulus outside the receptive field even though there was a stimulus within the receptive field. 5. Twenty-three percent (27/117) of neurons studied in the delayed-saccade task gave two bursts, one at the appearance of the stimulus and a second one around the saccade. This second burst generally did not occur when the monkey made the same saccade to a remembered target, but instead required the presence of the visual stimulus, and so we describe it as a reactivation of the visual response. Reactivation was also spatially specific. 6. The latency from reactivation to the beginning of the saccade ranged from 160 ms before the saccade to the beginning of the saccade. Reactivation usually continued for several hundred milliseconds after the saccade, sometimes for the duration of the trial. 7. Reactivation and enhancement are not the same mechanism. Although some cells showed both phenomena there was no correlation between enhancement and reactivation. 8. Cells that showed reactivation in the saccade task also showed reactivation at a weaker level in a suppressed-saccade task. In this task the monkeys had to hold fixation despite the disappearance of the fixation point and the continued presence of the peripheral stimulus.(ABSTRACT TRUNCATED AT 400 WORDS)

Miniature eye movements of fixation in rhesus monkey

1975 ◽  
Vol 15 (11) ◽  
pp. 1269-IN7 ◽  
Author(s):  
Alexander A. Skavenski ◽  
David A. Robinson ◽  
Robert M. Steinman ◽  
George T. Timberlake
Keyword(s):  
Eye Movements ◽  
Rhesus Monkey
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