Abstract Representations of Sensorimotor Transformations in Human Premotor Cortex

Abstract

Humans must flexibly adapt their movements across contexts to implement a vast repertoire of skills. This means the motor system should not only encode movement-specific information, but also context-specific representations linking goals to actions. Here, we asked if and how the human sensorimotor cortex encodes latent mappings between visual goals and movements. Participants learned to adapt wrist movements under two distinct visuomotor transformations, controlling a visual cursor that was either rotated or reflected away from their hand movement. Representational similarity analyses on fMRI data collected during the task dissociated neural activity patterns related to transformation context, movement direction, and target location. We observed distinct representational profiles within sensorimotor cortex: Premotor cortex activity patterns encoded both movement direction and transformation context, whereas primary motor cortex activity patterns encoded movement direction but not transformation context. Stronger transformation-context encoding in dorsal premotor cortex was associated with better task performance. Moreover, when the two transformations converged on the same movement solution, permitting a context-insensitive action selection strategy, individual differences in behavioral context sensitivity covaried with the degree to which transformation and movement representations overlapped in dorsal premotor cortex. These findings suggest that premotor cortex flexibly represents abstract sensorimotor transformations linking goals to actions, providing a neural interface between action selection strategies and motor commands.