Chapter 12 - Consciousness and control of action

Summary

Empirical evidence shows that much of the functioning of our motor system occurs without awareness. It seems that consciousness can manifest itself at three stages: intention to perform an action, performance of intended action, and perception of the effects of performed action. This chapter reviews the evidence that suggests that many aspects of action, from initiation to appreciation of the percepts that guide them, occur without awareness. It argues that one aspect of an action that is normally available to awareness is the sensory consequence(s) of that action, or, more precisely, the prediction of the sensory consequences of that action. Action execution depends on one of the two visual systems. There is a sensorimotor or "how" system, which controls visually guided behavior without access to consciousness. The other is a cognitive or "what" system, which gives rise to perception and is used consciously in pattern recognition and normal visual experience.