The relation between perception and action: What should neuroscience learnfrom psychology?

Research in neuroscience is making progress toward understanding the "dorsa l" mechanisms responsible for the fast modulation by optical information of actions such as reaching and grasping. The function of "ventral" visual pa thways is not to support perception, as distinct from action. Instead, it i s to control extended actions that unfold over longer time scales and draw on optical information over larger spatial scales, than simple, fast limb m ovements. Perception and sensation should be regarded as particular forms o f extended communicative actions and not as alternative end points for the use of environmental information. The neural mechanisms involved in control ling extended actions are not yet understood, and psychological theory has a role to play in framing their investigation by neuroscience.