Context-Dependent Motor Feedback Underlies Choice-Related signals in Visual Cortex

Choice-related neural activity, reflecting trial-by-trial correlation with subjects perceptual choice, is commonly observed in sensory cortices and has been implied in sensory readout. Recent studies suggest an alternative source from motor-reporting, yet its precise nature remain elusive due to limitations in conventional experimental paradigms. Here we quantitatively identified motor component by training macaques to discriminate visual motion directions via making saccade to spatial-independent, colored choice targets appeared under two contexts: at stimulus onset, or after its offset. Neural recordings in visual areas MT/MST revealed a dominant motor-related choice signal when the saccade goal was known in advance; this signal vanished with delayed target onset. By comparing with downstream sensory-motor transformation areas and employing a recurrent network model, we demonstrated that this motor component reflected feedback. Our work clarifies that a major portion of "decision" activity in sensory neurons is attributable to motor-reporting processes, highlighting the profound influence of behavioral context.