by Mridu Khullar Relph

It seems an unlikely place to find a discussion on free will, but neuroscientists often grapple with the question of who is making your life choices: Your brain or your consciousness? More importantly, what’s the difference?

A classic experiment from the 1970s and early 1980s that is referenced frequently in these discussions is the work of Benjamin Libet, which showed that the brain begins preparing for movement even before we consciously decide to move. In Libet’s experiment, people were asked to move a finger whenever they were ready. When they had the urge to move, all they had to do was check where the second hand was on the clock. Meanwhile, Libet measured the activity in his subjects’ brains and found that while the conscious decision to move the hand happened on average 200 milliseconds before the person moved their hand, the brain had already begun preparing for this movement a whole second in advance.

The experiment contradicted everything we had believed so far about decision-making. Until then, scientists thought that a person makes a conscious decision to act, and then the brain sends signals to the body that enables us to take that action. But this sequence of events was now under question. Do we really make our decisions, or are they made for us? And, if so, are we still responsible for them? Additionally, if someone were to monitor my brain, could he or she know, even before I do, what action I’m going to take?

More recently, a series of experiments conducted by neuroscientist Dr. John-Dylan Haynes in 2008 prove, he says, that he can tell before a person can what decision that person will make. In this study from the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, in collaboration with the Charité University Hospital and the Bernstein Center for Computational Neuroscience in Berlin, the researchers asked subjects to decide if they wanted to press a button with their left or their right hand. When making the decision, they were asked to remember the time at which they had made up their mind. The researchers studied the brain activity just before the process and found that they could predict from the brain activity which button the participants were going to press a full seven seconds ahead of time.

“Many processes in the brain occur automatically and without involvement of our consciousness,” the scientists wrote on publication of their findings. “This prevents our mind from being overloaded by simple routine tasks. But when it comes to decisions, we tend to assume they are made by our conscious mind. This is questioned by our current findings.”

But not everyone is entirely convinced. “I actually agree that the evidence is pointing in the direction that subconscious processes are making decisions, as it were,” says Dr. Steven Novella, an academic clinical neurologist at Yale University School of Medicine and the president and cofounder of the New England Skeptical Society. “The problem is that the fMRI studies are very tricky to do, and what you have to realize is that when you see a pretty picture of which parts of the brain are lighting up, that’s a composite. You’re not looking at a clear signal in one person’s brain as they’re doing the task. You’re looking at a composite over time and over different subjects, and when you think about it, this is a binary choice—A or B—and they’re looking at this little signal peaking above all this noise and coming up with 67–68% correlation. It’s actually not that much better than chance. Doesn’t mean it’s wrong. It’s just not that robust.”

So if it were indeed possible that scientists could predict the choices we’re going to make before we ourselves know, what could that mean? >>SUBSCRIBE TO READ CONCLUSION<<

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