Transforming vision into action.

Traditionally, research on vision focused on its role in perception and our cognitive life. Except for the study of eye movements, which have been regarded as an information-seeking adjunct to visual perception, little attention was paid to the way in which vision is used to control our actions, particularly the movements of our hands and limbs. Over the last 25 years all of that has changed. Researchers are now actively investigating the way in which vision is used to control a broad range of complex goal-directed action - and are exploring the neural substrates of that control. A new model of the functional organization of the visual pathways in the primate cerebral cortex has emerged, one that posits a division of labor between vision-for-action (the dorsal stream) and vision-for-perception (the ventral stream). In this review, I examine some of the seminal work on the role of vision in the control of manual prehension and on the visual cues that play a critical role in this important human skill. I then review the key evidence for the perception-action model, particularly with reference to the role of the dorsal stream in the control of manual prehension, touching on recent work that both reinforces and challenges this account of the organization of the visual system.