We analyzed the relationship between eye movements and neuronal responses recorded from area MT in alert monkeys trained to maintain visual fixation during the presentation of moving patterns. The monkeys made small saccades which moved the eyes with velocities that spanned the sensitivity range of MT neurons. The saccades evoked changes in the neuronal response that depended upon (1) the level of stimulusevoked activity amidst which the saccade occurred and (2) the direction of the saccade relative to the preferred direction of the neuron. Most notably, saccades were able to suppress stimulus-evoked activity when they caused retinal image flow that opposed the neuron's preference and were able to elicit a response or enhance weak activity when they caused flow in the neuron's preferred direction. On average, the disturbance lasted 40 ms beginning about 40 ms following saccade onset. Using these parameters, we simulated synthetic spike trains from an imaginary pair of similarly tuned n...

Abstract--Data concerning the possible role of a corollary discharge mechanism in the regulation of visual-oculomotor interactions are reviewed. Several modes of action for such a mechanism on the processing of visual information are discussed. Mere suppression of visual input during saccades is considered mostly as a peripheral mechanism. It is proposed that corollary discharge could either produce an active cancellation of the effects of eye movements on vision, or contribute to the evaluation that a given visual change is provoked by a saccade. Cancellation could occur at subcortical levels of visual processing although evaluation could occur at the cortical level.

A series of neurophysiological experiments on the responses of V1 neurons during saccadic eye movements were carried out. Strong suppression followed by rebound was observed in post-saccadic neural activities. These results showed that although the reduction in perceptual sensitivity during rapid eye movements was largely due to the smearing of visual stimuli during saccades, there exist saccade-related extraretinal signals mediating saccadic suppression at the neuronal level. Key Words Saccadic suppression; Orientation tuning; Primate visual cortex; Eye movement 1.

Abstract-We investigated why we have no perception of a smeared image resuhing from the reduction in contrast (grey-out) occurring at the retina during saccadic eye movements. By turning on light in the experimental room only during the eye movement. we were able to show that this grey-out was perceived as a smeared image of the visual scene. However, when the exnerimental room was illuminated before and/or after the saccade as well as during the saccade. perception of the grey-out was obliterated. During a period of fixation, perception of a blank image comparable in duration to an eye movement could also be eliminated by a preceding or following clear image. We conclude that lack of perception during saccadic eye movements made in normal contoured environments results primarily from the visual “masking ” effect of a clear image before and/or after the eye movement acting on the grey-out during the eye movement. This “saccadic omission ” is entirely a visual phenomenon and is far more tmwerful than the usuallv studied elevation of visual threshold for detection of a flash. “saccadic suppression.” Our vision is interrupted several times a second by rapid eye movements (saccades) made from one point in the visual field to another. During these saccades

Comparison of effects of eye movements and stimulus movements on striate cortex neurons of the monkey.