The control of action has traditionally been described as "automatic". In particular, movement control may occur without conscious awareness, in contrast to normal visual perception. Studies on rapid visuomotor adjustment of reaching movements following a target shift have played a large part in introducing such distinctions. We suggest that previous studies of the relation between motor performance and perceptual awareness have confounded two separate dissociations. These are: (a) the distinction between motoric and perceptual representations, and (b) an orthogonal distinction between (...) conscious and unconscious processes. To articulate these differences more clearly, we propose a new measure of motor awareness, based on subjects' ability to reproduce the spatial details of reaching movements they have just made. Here we focus on the dissociation between motor awareness and perceptual awareness that may occur when subjects make rapid visuomotor adjustments to reaching movements following a target shift. In experiment 1, motor awareness was dissociated from perceptual awareness of a target shift during reaching movement. Participants' reproduction of movement endpoints following visuomotor adjustment was independent of whether they saw the target shift or not. Experiment 2 replicated this result, and further showed that neither motor awareness nor motor performance were disrupted by TMS over the parietal cortex. The neural mechanisms underlying motor awareness, and the implications for theories of consciousness, are discussed. (shrink)
Psychologists have traditionally approached phenomenology by describing perceptual states, typically in the context of vision. The control of actions has often been described as 'automatic', and therefore lacking any specific phenomenology worth studying. This article will begin by reviewing some historical attempts to investigate the phenomenology of action. This review leads to the conclusion that, while movement of the body itself need not produce a vivid conscious experience, the neural process of voluntary action as a whole has distinctive phenomenological consequences. (...) The remainder of the article tries to characterise this phenomenology. First, the planning of actions is often conscious, and can produce a characteristic executive mode of awareness. Second, our awareness of action often arises from the process of matching what we intended to do with what actually happened. Failures of this matching process lead to particularly vivid conscious experience, which we call 'error awareness'. These features of action phenomenology can be directly related to established models of motor control. This allows an important connection between phenomenology and neuroscience of action. Third, whereas perceptual phenomenology is normally seen as caused or driven by the sensory stimulus, a much more fluid model is required for phenomenology of action. Several experimental results suggest that phenomenology of action is partly a post hoc reconstruction, while others suggest that our awareness of action represents an integration of several processes at multiple levels of motor processing. Fourth, and finally, studies of the phenomenology of action, unlike those of perception, show a strong linkage between primary awareness and secondary awareness or self-consciousness: awareness of action is specifically and inextricably awareness of my action. We argue that the concepts of agency and of proprioaction are fundamental to this linkage. For these reasons, action represents a much more promising field than perception for attacking the problematic question of the relation between primary and secondary consciousness. Some promising directions for future research are indicated. (shrink)