Libet Experiment

A pioneering experiment in this field was conducted by Benjamin Libet in the 1980s, in which he asked each subject to choose a random moment to flick their wrist while he measured the associated activity in their brain (in particular, the build-up of electrical signal called the Bereitschaftspotential (BP), which was discovered by Kornhuber & Deecke in 1965^[37]). Although it was well known that the “readiness potential” (German: Bereitschaftspotential) preceded the physical action, Libet asked how it corresponded to the felt intention to move. To determine when the subjects felt the intention to move, he asked them to watch the second hand of a clock and report its position when they felt that they had felt the conscious will to move.^[38]

Libet found that the unconscious brain activity leading up to the conscious decision by the subject to flick their wrist began approximately half a second before the subject consciously felt that they had decided to move.^[38][39] Libet’s findings suggest that decisions made by a subject are first being made on an unconscious level and only afterward being translated into a “conscious decision”, and that the subject’s belief that it occurred at the behest of their will was only due to their retrospective perspective on the event.