Conversion of Working Memory to Motor Sequence in the Monkey Premotor Cortex

TLDR

The study investigates how serial sensory information is held in memory and converted into a motor program for planning serial order behavior. Monkeys were trained to memorize positional cue sequences and reproduce them with saccades, with the order decided mid‑trial by an instruction stimulus; transient dorsal premotor neurons together with sustained neurons that encode cue or movement sequences mediate the conversion of maintained information into a motor program. Neurons in the dorsal premotor cortex transiently fired in response to the instruction stimulus only when the sequence order had to be determined.

Abstract

To plan a serial order behavior, we hold serial sensory information in our minds and convert it to a movement program. We trained monkeys to memorize a sequence of positional cues and to reproduce it by making saccades in either the original or reverse order. The order was determined in the middle of a trial on the basis of an instruction stimulus. Triggered by the instruction stimulus, single neurons in the dorsal premotor cortex became transiently active only when the order needed to be determined. These transient neurons, together with nearby sustained neurons that hold information on cue or movement sequences, appear to mediate the generation of a motor program from the maintained information.