Sensory-to-motor transformations: From serial pipelines to dynamic, distributed processes.

A key organizing principle of nervous systems is the transformation from sensation into action. Accordingly, studies of sensory-to-motor transformations have yielded foundational insights into nervous system structure and function. Here, we provide a broad review of goal-directed (as opposed to reflexive) sensory-to-motor transformations. We synthesize theoretical and experimental frameworks for linking sensory-related and motor-related neuronal activity to behavior. We provide a historical overview of sensory-to-motor transformation studies, describing evidence for the propagation of neuronal activity within neocortex transforming sensory encoding into decision formation and motor execution. We then describe emerging evidence that challenges this traditional perspective, emphasizing parallel processing, distributed representation, and shifts in cortical dependence with learning. We conclude by identifying key open questions that present exciting opportunities for future discovery. Building upon decades of foundational research, ongoing and future studies of sensory-to-motor transformations are poised to reveal the dynamic, distributed neuronal mechanisms that enable flexible linkages between sensation and action.