To move or to sense? Incorporating somatosensory representation into striatal functions.

A long-standing hypothesis postulates that the striatum is essential for the concurrent selection of adaptive actions and repression of inappropriate alternatives. Here, classical and recent anatomical and physiological studies are reviewed to show that, in mammals, the striatum can detect discrete task-relevant sensory stimuli and continuously track somatosensory information associated with the generation of simple movements and more complex actions. Rather than contributing to the immediate selection of actions, the striatum may monitor the sensorimotor state of animals by integrating somatosensory information and motor-related signals on a moment-by-moment basis. Such function could be critical for the progressive acquisition or updating of adaptive actions and the emergence of an embodied sense of time.