IS FREE WILL AN ILLUSION?

Neuroscience could hold the key to answering one of philosophy's oldest questions

- NATE SCHARPING

Whether or not we have free will is a question philosophers have been debating for millennia. In the early 1980s, there was a brief moment when it appeared the debate may finally have been settled. The potential solution came not from philosophy, but neuroscience.

The answer, somewhat depressingly, was that free will didn't exist. Experiments carried out by the neuroscientist Benjamin Libet appeared to show decisions being made in the brain before people were even aware of them. It was as if science had finally revealed the strings of the puppet master controlling our thoughts and actions.

To even casual observers of the history of inquiries into free will, this pronouncement felt premature. Thankfully, they were right. Scientists today are much more sceptical not only of the idea that free will doesn't exist, but also of the notion that brain scans will ever definitively prove or disprove its existence. But why?

HOW YOU MAKE A DECISION

Ultimately, the question of free will may be best left to philosophers, but that doesn't mean it's a topic neuroscientists should ignore. Experiments into how the human brain makes decisions have led to important insights into neurology and psychology, and have expanded our understanding of the brain's inner workings.

Those experiments include the ones Libet conducted in the 1980s, which, although viewed in a more critical light now, paved the way for decades of innovative research. The experiments were simple. Libet attached volunteers to an electroencephalogram (EEG) machine to monitor their brain activity, then placed a button in front of them and asked them to decide when they wanted to press it. While they were deciding, they had to watch a timer, consisting of a dot moving around the inside of a circle (like a second hand on a clock). Each volunteer had to note the dot's position when they decided to press the button.