Saccade size and lambda complex in man

Abstract

Temporal relationships between saccade size and lambda complex were studied for four sizes of saccades. Occipital EEGs, time-locked to onset and offset of the saccade, were averaged 50 times for each size of saccade. With averaging time-locked to onset, the latency from onset of the saccade and amplitude increased for later components in proportion to the saccade size, while there was little change in the early positive component. In offset averages, the latency of the later responses from offset of the saccade was constant while the time of the early component from offset of the saccade increased with increasing saccade size. It was concluded that the lambda complex consisted of two groups of components: one associated with onset and one with offset of the saccade. The lambda response itself appears to be the response evoked by the afferent inflow at fixation.