I didn’t do it, my brain did.

Bereitschaftspotenzial_fig1A recent article in Consciousness and Cognition continues the debate over Benjamin Libet’s famous free will experiment.

In 1983 Libet showed that before subjects announced their decision to perform an action (and hence, or so Libet assumed, before deciding to perform an action) their motor cortex was already preparing the way for the act in question. Libet concluded:

“These considerations would appear to introduce certain constraints on the potential of the individual for exerting conscious initiation and control over his voluntary acts.” (Libet et al. 1983)

Jeff Miller and Judy Trevena were sceptical. So they set out to test Libet’s interpretation of his own experiment. In Miller and Trevena’s successor, subjects were asked to wait for an audio tone before making a decision. If the activity detected by Libet really was the making of the decision prior to any conscious awareness of doing so, then that activity ought to occur only if the subjects decided to act. But no such correlation was found.

As with the original experiment, it may not be difficult to pick holes in the purported connection between it and the philosophical question broached. But the debate continues.

For a summary of the research go here.

Related articles:
£1.99 - small Recent work on Free Will and Moral Responsibility
By Neil Levy and Michael McKenna, University of Melbourne Florida State University
(Vol. 3, December 2008)
Philosophy Compass

£1.99 - small Experimental Philosophy
By Joshua Knobe , University of North Carolina – Chapel Hill
(Vol. 1, November 2006)
Philosophy Compass

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