Free The Illusion of Conscious Will by Daniel M. Wegner Page A

with at home. Botvinick and Cohen (1998) reported, for example, a nice demonstration of such “tactile ventriloquism” with a rubber hand. When a person’s own arm is stroked gently out of view in sync with the stroking of a rubber hand that is in view, it just takes a little while for the person to begin reporting that the rubber hand feels like their own. Ramachandran and Blakeslee (1998) report a similar example, in which a person watches a spot on the table being tapped in rhythm with taps on their own hand under the table. After a bit of this, the person reports feeling the taps on the table, and in fact, a sharp rap on the table yields a startle response that can be measured as an increase in the person’s skin conductance level.
    Overall, these studies of muscle effort and of phantom limbs suggest that the experience of conscious will is not anatomically simple. There does not seem to be “will wiring” spilling from the connections between brain and body, and one begins to wonder whether the muscles are even a necessary part of the system. In a sense, it is not clear that any studies of the sense of effort in movement can isolate the anatomical source of the experience of conscious will. Although the hope of isolating the experience of will is certainly one of the motivations of the researchers studying muscle sense and phantom limbs, a key case of willed action is left out in this approach—the action of the mind (Feinberg 1978). We all do things consciously with our minds, even when our bodies seem perfectly still. William James (1890, 452) described the “voluntary acts of attention” that go into willful thought, and this effort of attending seems quite as palpable as the effort that goes into muscle movement.
    Ask a fifth grader, for example, just how much effort she put into a long division problem despite very little muscle movement except for pencil pushing and the occasional exasperated sigh. She will describe the effort at great length, suggesting that there is something going on in her head that feels very much like work. All the effort that people put into reasoning and thinking does not arise merely because they are getting tired scratching their heads. The question of whether there is a sense of effort at the outset, as the mental act starts, or only later, when the mental act has returned some sort of mental sensation of its occurrence, be-gins to sound silly when all the components of this process are in the head. Rather, there is an experienced feeling of doing, a distinct sense of trying to do, but this doesn’t seem to have a handy source we can identify. Certainly, it doesn’t seem to be muscle sense. 5 But it also doesn’t seem to be a perception of a brain signal going out to some other part of the brain. The experience of consciously willing an action may draw in some ways upon the feeling of effort in the muscles, but it seems to be a more encompassing feeling, one that arises from a variety of sources of sensation in the body and information in the mind.
    5 . Someoneperseveringonthemuscleexplanationherecouldreplythat thoughts can involve unconscious movement of the vocal muscles, which in fact is sometimes true (Sokolov 1972; Zivin 1979). However, then it would also have to be suggested that muscles move for all conscious thoughts, and this has not been established (but see Cohen 1986).
    Brain Stimulation
    The most direct anatomical approach to locating conscious will involves poking around in the living human brain. This approach is not for the squeamish, and nobody I know would be particularly interested in signing up to be a subject in such a study. So there is not much research to report in this area. The primary source of evidence so far is research con-ducted in the 1940s and 1950s—the famous “open head” studies by the neurosurgeon Wilder Penfield. Penfield mapped a variety of sensory and motor structures on the brain’s surface by electrically stimulating the cortical