REPRESENTATION OF AVERAGING SACCADES IN THE SUPERIOR COLLICULUS OF THE MONKEY

We tested the hypothesis that averaging saccades occur when two differ ent saccades are prepared and executed simultaneously. The activity of saccade-related burst neurons (SRBNs) in the primate superior collicu lus was recorded while monkeys made both non-averaging saccades to sin gle targets and averaging saccades which directed the gaze between two simultaneously presented visual targets. For movements of comparable direction and amplitude, the activity measured during averaging and no n-averaging saccades was statistically indistinguishable. These result s are not consistent with the hypothesis that averaging saccades resul t from the simultaneous execution of two different saccades at the lev el of the collicular SRBNs. Instead, these findings indicate that aver aging saccades are represented as single intermediate movements within the topographically organized map of these collicular cells.