Duel against the
computer: a participant during the Experiment,
Copyright:
Charité, Carsten Bogler
(January 5, 2015) Our
choices seem to be freer than previously thought. Using computer-based brain
experiments, researchers from Charité – Universitätsmedizin Berlin studied the
decision-making processes involved in voluntary movements. The question was: Is
it possible for people to cancel a movement once the brain has started
preparing it? The conclusion the researchers reached was: Yes, up to a certain
point – the 'point of no return'. The results of this study have been published
in the journal PNAS.
The background to this new set of experiments lies in the debate
regarding conscious will and determinism in human decision-making, which has
attracted researchers, psychologists, philosophers and the general public, and
which has been ongoing since at least the 1980s. Back then, the American
researcher Benjamin Libet studied the nature of cerebral processes of study
participants during conscious decision-making. He demonstrated that conscious
decisions were initiated by unconscious brain processes, and that a wave of
brain activity referred to as a 'readiness potential' could be recorded even
before the subject had made a conscious decision.
How can the unconscious brain processes possibly know in
advance what decision a person is going to make at a time when they are not yet
sure themselves? Until now, the existence of such preparatory brain processes
has been regarded as evidence of 'determinism', according to which free will is
nothing but an illusion, meaning our decisions are initiated by unconscious
brain processes, and not by our 'conscious self'. In conjunction with Prof. Dr.
Benjamin Blankertz and Matthias Schultze-Kraft from Technische Universität
Berlin, a team of researchers from Charité's Bernstein Center for Computational
Neuroscience, led by Prof. Dr. John-Dylan Haynes, has now taken a fresh look at
this issue. Using state-of-the-art measurement techniques, the researchers
tested whether people are able to stop planned movements once the readiness
potential for a movement has been triggered.