A recent study into the neuroscience of free will reopens an ancient debate.
Free will and its arch nemesis, determinism, have been battling since philosophy's ancient conception.
Do we, as humans, choose our actions, or are we simply drifting along a predetermined path at the mercy of the fates?
On the surface, to a modern mind, free will seems like it should have the upper hand. After all, it was you who decided to order large fries, and you know only too well that you can blame no one else for opening that second beer.
But, historically, neuroscientific enquiry did not find the evidence for free will as forthcoming as one might imagine.
The earliest neurophysiological research into free will began in the 1980s with the work of Benjamin Libet. He constructed a number of experiments that seemed to fall in favor of a more deterministic state of affairs.
For Libet's landmark study, he asked participants to flick their wrist at random points in time while he measured their brain waves. Libet found that he could measure a build up of neurological activity before the wrist was flicked.
It seemed that the neurological activity preceded the participant's conscious decision to move. This brain activity was dubbed the readiness potential.
The death of free will?
At the time, other scientists considered that this readiness potential might, in fact, be the cause of the movement. Therefore, Libet's next challenge was to see if the readiness potential could be detected before the conscious intention to move was registered.
In other words, did the brain know what the participant was going to do before the participant knew they were going to do it?
To this end, Libet asked participants to watch a clock, and, after having made the random wrist movement, he asked them at what exact time they had decided to make the action. Libet found that the unconscious readiness potential began roughly half a second before the individual reported having decided to move.
From these experiments, and others in the same vein, many were eager to be rid of free will altogether. But, as with most neuroscientific endeavors, the truth is a lot more complicated than it might first appear.
The rebirth of free will
A recent study, carried out at the Charité's Bernstein Center for Computational Neuroscience in Berlin, Germany, has reopened this age-old debate. Published in the Proceedings of the National Academy of Sciences, the results are fascinating.
The team, led by Prof. John-Dylan Haynes, wanted to find out whether the readiness potential could be vetoed by the brain. In other words, once the unconscious brain had decided on a course of action, could the conscious brain override it?
Prof. Haynes explains:
"The aim of our research was to find out whether the presence of early brain waves means that further decision-making is automatic and not under conscious control, or whether the person can still cancel the decision, i.e., use a 'veto.'"
To this end, they came up with an ingenious experiment. Participants were pitted in a "duel" with a computer while their brain waves were monitored using electroencephalography (EEG).
The computer was trained to effectively read the human player's mind. When the program detected the EEG readiness potential associated with the participant's next move, the computer would preempt it, making its move before the human was even conscious that they were about to make that move.
A split-second veto
The researchers found that, despite the computer's ability to preempt the motions of its challenger, the human was indeed able to change their mind at the last split second.
Professor Haynes explains the results:
"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. 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."
This will certainly not be an end to the discussion of free will. There are still limitations that the professor wishes to investigate further.
"There is a 'point of no return' in the decision-making process, after which cancelation of movement is no longer possible," he says.
The team plans to continue their research into these fascinating split-second decisions. For the next round of investigations, they will look at how more complicated decisions are affected by the mind-reading computer program.
As neuroscience becomes ever more technologically advanced, etherial questions will, no doubt, be unfurled and laid bare. Medical News Today recently covered a study looking at the neuroscience of jazz improvisation.