MOVEMENT KINEMATICS ENCODED IN COMPLEX SPIKE DISCHARGE OF PRIMATE CEREBELLAR PURKINJE-CELLS

MONKEYS performed a multijoint arm-reaching task that systematically v aried movement direction and distance. Purkinje cell activity was reco rded from 231 task-related cells, and the complex spike discharge was analyzed in relation to distance and direction. The complex spike acti vity of 123 Purkinje cells changed significantly relative to the backg round rate. Of these 123, the activity of 85 cells was related to dist ance and/or direction. The complex spike activity of 54 of these 85 ce lls fitted a cosine tuning curve for direction, generally at one dista nce. Using a simple linear regression model, the complex spike activit y of 56 cells was significantly correlated with movement distance, usu ally in one direction. We conclude that the complex spike discharge of Purkinje cells is spatially tuned and strongly related to movement ki nematics.