Researchers Explain Mechanism behind the Science of Free Will

Sharon Moore January 26, 2016

Do we really have ‘free will’? Using computer-based brain experiments, researchers from Charité - Universitätsmediz in Berlin studied decision-making processes involved in voluntary movements. They sought to determine whether or not it possible for people to cancel a movement once the brain has started preparing it. And the answer is - yes - but up to a certain point, in which case there’s no more turning back. 

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. The research team, 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. 

In a series of computer-based experiments, researchers asked study participants to enter into a ’duel’ with a computer, and then monitored their brain waves throughout the duration of the game using electroencephalography (EEG). A specially-trained computer was then tasked with using these EEG data to predict when a subject would move, the aim being to out-manoeuvre the player. This was achieved by manipulating the game in favour of the computer as soon as brain wave measurements indicated that the player was about to move.  

Researchers were able to demonstrate that participants’ control over their actions can be retained for much longer than previously thought. 

"A person’s decisions are not at the mercy of unconscious and early brain waves. They are able to actively intervene in the decision-making process and interrupt a movement," says Prof Haynes. "Previously people have used the preparatory brain signals to argue against free will. Our study now shows that the freedom is much less limited than previously thought. However, there is a ’point of no return’ in the decision-making process, after which cancellation of movement is no longer possible." The researchers plan to investigate further some other complex decision-making processes. 

Source of this article:

Matthias Schultze-Kraft et al. The point of no return in vetoing self-initiated movements, Proceedings of the National Academy of Sciences