Neuronal activity correlated with eye movement in the cat's pretectum.

Single unit activity correlated with horizontal and vertical saccades was recorded in darkness from n. pretectalis anterior (NPA), n. pretectalis olivaris (NPO), n. tractus opticus (NTO) and n. pretectalis posterior (NPP). The units studied fell into two classes. The first class neurons displayed a high frequency burst of activity prior to the onset of a saccade regardless of where the eye was when the movement started. These neuronal reponses, mainly recorded from NPA and NPO, can therefore be ascribed to the motor aspect of the eye movement. The second type units, mostly found in NPP and NTO, responded after the initiation of a saccade and might be ascribed to a postsaccadic facilitation related to the visual attention during the fixation period.