Abstract
We identified the pre-saccadic spike potential and post-saccadic lambda response related to the fast phase of optokinetic nystagmus (OKN). To induce horizontal OKN, 23 participants individually sat inside a rotating drum and viewed a whole-field grating pattern moving horizontally at a velocity of 24 or 60 deg/s. Electroencephalograms were recorded from an occipital electrode (Oz) and averaged by time-locking to either onset or offset of the fast phase. As a result, the positive spike potential, which peaked 5 ms after fast phase onset, was obtained clearly when that was the trigger point. The positive lambda response was obtained with both trigger points, and showed a peak about 90 ms after fast phase offset. The lambda response was attenuated and delayed with an increase of stimulus velocity that caused a large retinal slip to degrade clear vision. That suggested visual processing after rapid eye movement affected the lambda response of OKN, as well as the response of voluntary saccade. (Japanese Journal of Physiological Psychology and Psychophysiology, 21 (3) : 239-244, 2003.)
