MODIFICATION OF CORTICAL CLICK-EVOKED RESPONSE DURING EYE MOVEMENT IN CATS

1. 1. Optokinetic nystagmus was induced in four cats by moving vertical black and white stripes before their eyes. The response to click stimuli triggered by the eye movements was recorded from electrodes chronically implanted along the classical auditory pathway. 2. 2. Computer-averaged click-evoked responses from the cortex declined linearly in amplitude as a function of eye movement velocity; no such relationship existed at subcortical auditory nuclei. 3. 3. Within 15 msec after the onset of eye movement the amplitude of cortical evoked responses was substantially reduced, and at 100 msec, when the velocity of movement was beginning to decline, the depression was at its maximum (50% of control amplitude). 4. 4. Despite their disparate time courses, eye movements and depression of the cortical auditory evoked response are clearly interrelated. Some properties of a central mechanism that could be responsible for this are described. © 1969.