Voluntary Action, Illusion of

Suppressibility

It has been proposed by Richard Passingham that unlike involuntary actions (e.g., reflexes, automatisms during seizures, and unconscious actions during pathological states), voluntary actions are special in that they can be suppressed. Though involuntary actions may be counteracted, as when the patellar (knee-jerk) reflex is counteracted by contracting the leg muscles, such indirect control is different from the kind of direct suppression that occurs during voluntary action, as when one refrains from making a comment or dropping a hot dish. Hence, suppressibility serves as a useful behavioral index of voluntary action in humans and other species.

Sense of Agency and Ideomotor Processing

With respect to one's subjective experience, however, voluntary and involuntary action could not feel more different from each other. As researched extensively by Daniel Wegner and colleagues, the subjective sense of agency associated with voluntary action is based on several high-level cognitive processes, including the perception of a lawful correspondence between action intentions and action outcomes. If one intends to flex one's index finger and then it happens to flex, one is likely to believe that the movement was voluntary. One is unconscious of the sophisticated motor programs giving rise to the action outcome but is often aware of the perceptual consequences (e.g., perceiving flexing a finger). William James and contemporary “ideomotor” theorists such as Wolfgang Prinz propose that, for voluntary action, the conscious mind then uses such perceptual-like representations to later influence the generation of motor efference (the signals to the muscle fibers), which itself is an unconscious process. From this standpoint, when one deliberately performs an action, one aims to reproduce the same sensations that occurred when a similar action was done in the past. To effect a desired efference to the muscles, all the conscious mind has to do is pay a certain kind of attention to such perceptual-like representations. Then, following some sort of “go” signal and if not curbed or controlled by James's “acts of express fiat” (i.e., exercise of veto), unconscious motor programs take care of the rest by meticulously activating the right muscle fibers at [Page 773]the right time, thus giving rise to the action. John Bargh's classic research demonstrates that incidental stimuli, such as ambient objects in one's environment (e.g., a dartboard) can unconsciously activate processes that then influence one's behavioral dispositions (e.g., making one more competitive).

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