Selective coding of motor sequence in the supplementary motor area of the monkey cerebral cortex

We describe a property of neurons in the supplementary motor area (SMA) of the cerebral cortex of monkey that is different from those in the primary motor area (MI) in relation to execution of a sequential motor task. A group of SMA neurons was active when the animal remembered and pressed three touch-pads in a predetermined sequence but inactive when the same movement was guided by sequentially presented visual signals. This finding indicates that the SMA is involved in the performance of sequential movements on the basis of the information stored inside the brain.