NEURONAL CODING OF STIMULUS-RESPONSE ASSOCIATION RULES IN THE MOTOR CORTEX

Two monkeys were trained to perform wrist movements to align a pointer with visual targets. In the spatially 'compatible' condition, monkeys had to point at the target position (left/right), whereas in the 'inc ompatible' condition, they had to point at the position opposite to th e target. A large proportion of neurones recorded in the primary motor cortex showed changes in activity according to either the side of the target or the side of the movement, However, more than 40% of neurone s changed their activity as a function of the stimulus-response mappin g rule. Some of these neurones, being sensitive only to the stimulus-r esponse compatibility effect, must therefore be viewed as specifically involved in the neural mechanisms that control the association proces s between sensory inputs and motor outputs.