their obviously intended and voluntary action. Often a cloud of dust remains. In the case of real people, however, knowing whether another person has done something willfully can be a detective exercise. In some of the most important cases, these things must even be decided by the courts or by warfare, and no one is really satisfied that the willfulness of actions judged after the fact is an accurate reflection of a person’s state at action onset. Perhaps we need a lightbulb over our head that flashes whenever we do something on purpose.
But how would the lightbulb know? Is there some place in the mind or brain that lights up just as we perform a consciously willed action, a place to which we might attach the lightbulb if we knew the proper wiring? Certainly, it often seems that this is the case. With most voluntary actions, we have a feeling of doing. This feeling is such a significant part of consciously willed acts that, as we have seen, it is regarded as part of their definition. Will is the feeling that arises at the moment when we do something consciously—when we know what it is we are doing, and we are in fact doing it. What is it we are feeling at this time? Is it a direct expression of a causal event actually happening somewhere in our mental or neural architecture? Or is it an inference we make about ourselves in the same way we make an inference about the cartoon character when we see the lightbulb?
We can begin to grasp some answers to such questions by examining the anatomical and temporal origins of the experience of will. Where does the experience of will come from in the brain and body? When exactly does it arrive? In this chapter we examine issues of where the will arises by considering first the anatomy of voluntary action—how it differs from involuntary action and where in the body it appears to arise. We focus next on the sensation of effort in the muscles and mind during action to learn how the perception of the body influences the experience of will, and then look directly at the brain sources of voluntary action through studies of brain stimulation. These anatomical travels are then supplemented by a temporal itinerary, an examination of the time course of events in mind and body as voluntary actions are produced. In the process of examining all this, we may learn where, when, and how we get the feeling that we’re doing things.
Where There’s a Will
Many modern neuroscientists localize the “executive control” portion of the mind in the frontal lobes of the brain (e.g., Stuss and Benson 1986; 1987). This consensus derives from a host of observations of what hap-pens in human beings (Burgess 1997; Luria 1966, Shallice 1988) and animals (Passingham 1993) when portions of the frontal lobes are damaged or missing. Such damage typically leads to difficulties in the planning or initiation of activity as well as loss of memory for ongoing activity. This interlinked set of specific losses of ability has been called the frontal lobe syndrome. A person suffering from this syndrome might be unable to plan and carry out a simple act such as opening a soda can, for example, or might find it hard to remember to do things and so be unable to keep a job. 1 This widely observed phenomenon suggests that many of the causal sequences underlying human action may be localized in brain structures just under the forehead. Brain-imaging studies also suggest that voluntary actions are associated with activity in the frontal region (Ingvar 1994; Spence et al. 1997). However, this sort of evidence tells us little about where the experience of will might arise.
1 Antonio Damasio (1994) retells the story of one man suffering such damage, Phineas P. Gage, who survived a blasting accident that sent a metal rod up through his left cheek and out the top of his head, destroying his left frontal lobe. Although Gage recovered physically, and indeed appeared to have suffered no change in his level of everyday intelligence,