Reclaiming conscious agency

Posted by anon on 17 December 2009 | 3 Comments

Tags: freewill, consciousness, voluntary movement, Libet

This reviews a recent paper by Alexander Batthyany, which looks at the implications of experiments by Benjamin Libet and more recently C.S. Soon, for the existence or otherwise of freewill. Libet's subjects were asked to make voluntary finger movements. The experiments showed that a readiness potential was detected in the brain 350 milliseconds before a movement, while the subjects were aware of their conscious intention to act only 200 ms before the movement. Therefore, neuronal activity preparatory to movement happened 150 ms before conscious awareness of the intention to act.

Libet himself did not support the view that his experiments showed that there was no such thing as conscious will. He found that some subjects reported an urge to action, which they nevertheless decided not to carry out. On this basis, Libet took the view that conscious will could operate a veto on urges arising from earlier readiness potentials in the brain. The impulse from the readiness potential could be vetoed in the 200 ms interval between conscious awareness and action. This idea allows consciousness some causal efficacy, and this very definitely places Libtet's view outside of mainstream consciousness thinking. Researchers and commentators in the freewill area are not always aware of Libet's personal interpretation.

With Soon's experiment, it was claimed that there was no evidence for the veto function suggested by Libet. However, Batthyany argues that this experiment was set up in such a way that the veto capacity was unlikley to be manifested. In the Libet experiment, subjects had been allowed to ignore their initial urge, wherreas in the Soon experiment, they were instructed to act immediately, in response to the first urge.

A variety of arguments are put forward against the view that the Libet/Soon experiments constitute a refutation of the existence of freewill. A distinction is made between, on the one hand, urges or experiences of which we are passively aware, and on the other, actively created intentions and actions. Examples of the passive kind of experience or desire are hunger or preferences for particular types of food. Such things are consciously experienced, but are not felt to have arisen from any act of conscious will or decision. In other cases, however, the conscious awareness of an intention or an action is felt as arising from the conscious will. Even in mainstream thinking it is usually accepted that this is what it feels like, but here, the feeling is taken to be an illusion.

Batthyany argues that the Libet/Soon experiments only study the passive and not the active type of experience, and these experiments are therefore invalid in respect to the debate about the existence of freewill. The instruction in the Libet experiments to wait for an urge to act is argued to fall into the category of a passive desire, rather than a willed intention. On this basis, Libet's experiments are argued to merely confirm the intuitive feeling that passive desires such as hunger are not consciously willed. In merely referring to such passive urges, the Libet/Soon experiments are argued to tell us nothing about the nature of consciously willed intentions or actions.

Soon's study closely follows Libet, but with the additional feature of the subjects having to press one of two buttons with their left or right index finger. Activity relative to this decision was found to precede the action by up to ten seconds. In 60% of cases, the researchers were able to predict which button the subject would press. Much has been made of the statistically significant 10% margin over chance. However, the author argues that because there is no apparent reason to choose on option over the other, this choice will also end up being the result of a passive urge, and is therefore also irrelevant to the question of freewill.

Batthyany's criticism of Libet-type experiments, to the effect that they do not deal with actively willed decisions, but only with passive urges, overlaps with my own criticism of the Libet based argument against freewill, to the effect that they only deal with the trivial type of actions that are very often performed on autopilot, and too conveniently ignore the more deliberative, strategic or long-term decisions that might be thought to be more relevant to the question of freewill.