In the absence of a central spot, remote motion had inhibitory effects on the firing rates of the majority of relay cells but its effect on retinal ganglion cells was mainly excitatory. When the shifting grating covered the classical receptive field and its periphery, facilitatory effects or suppressive effects, depending on the spatial phase of the pattern, were observed in both retinal and geniculate cells. Remote motion strongly suppresses the responsiveness of relay cells to stimuli within the classical receptive field. This suppressive effect involves intrageniculate processing and is primarily associated with a reduction in contrast gain. It is likely that shift suppression contributes to the loss of visual sensitivity observed in saccadic suppression.
Peripheral shift reduces visual sensitivity in cat geniculate neurones.
The sudden displacement of the retinal image during a saccade raises the visual threshold of human observers to foveal stimuli. The fall in visual sensitivity observed during this phenomenon, known as saccadic suppression, seems to occur very early in the visual processing chain. The spots were presented either alone or time-locked with the rapid movement of a large, high contrast peripheral pattern, referred to as shift. In experiments with human observers the task was to indicate, by a keypress, whichof two otherwise identical temporal intervals contained the spot. The shift also reduces the sensitivity of human observers to the same target.