YOUR MYSTERIOUS BRAIN

Science has mapped the surface of Mars and translated the code for life. By comparison, we know next to nothing about what’s between our ears. Over the next few pages, we ask leading scientists to answer some of the most important questions about our brains…

Do we really have free will?

DR LISA FELDMAN BARRETT

Lisa is a professor of psychology at Northeastern University. Her latest book is Seven And A Half Lessons About The Brain (£14.99, Picador).

The question of free will is still hotly debated. On the one hand, we clearly experience ourselves as able to make choices and freely act on them. If you fancy some crisps, you can choose to walk into a shop, buy a packet and eat them. Or you can choose to eat a pastry, a salad, or nothing at all. This certainly feels like free will.

On the other hand, neuroscience evidence clearly shows that the brain usually initiates our actions before we’re aware of them. Here’s what I mean. Your brain’s primary task is to regulate the systems of your body to keep you alive and well. But there’s a snag: your brain spends its days locked in a dark, silent box (your skull) with no direct access to what’s going on inside your body or outside in the world. It receives ongoing information about the state of your body and the world – ‘sense data’– from the sensory surfaces of your body (your retina in your eyes, your cochlea in your ears, and so on). These sense data are outcomes of events in the world and inside your body. But your brain does not have access to the events or their causes. It only receives the outcomes. A loud bang, for example, might be thunder, a gunshot, or a drum, and each possible cause means different actions for your brain to launch.