Who’s The Decision Maker: Your Brain Or You?

(Editor’s note: This article is from a past issue of Brain World magazine. If you enjoy this article, please support us with a print or digital subscription!)

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?


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 to 68 percent 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?

Dr. Haynes believes that his results could have huge commercial applications. “A lot of practical applications that we might want to build, technologies, can be built on very simple binary choices,” he told the BBC in an interview. “So if you want to build a lie detector, you want to know if this person is lying yes or no. You don’t need to know all the details of a person’s thoughts. If you want to build a device that can tell if a specific consumer product will be liked by the consumers or not, then you just need a decision yes or no.”

Regarding a traditional lie detector, this would be more accurate because the response would be measured directly from the subjects’ brain and not based on what they say. Even before the subject answered a question, you’d know whether or not he was lying. Also, by measuring someone’s brain activity, you’re able not only to judge what he’s saying now, but how he’s going to act in the future. Even before the person has acted, we could potentially know how he or she will. Does that absolve the person of responsibility for his future action? Can it be preventive? Those are the questions that scientists now seem to be grappling with.

On the morality and ethicality of that, Dr. Haynes went on to say, “I think at least the worry’s there that they can get deeper into you, that they can read something that you might yourself not even be aware of — say, for example, some racial bias, some prejudice that you might have. You might not be aware of this; we might be able to find this out with brain scanning, so I think there’s an ethical issue there. How much do we want to find out, how much should we feed back to people, how much should we be able to use this and say, for example in court or commercial examples? There’s a huge debate there.”

But don’t worry just yet. Dr. Novella believes that this kind of technology is nowhere near ready to be useful for things like lie detection. “It’s not like you can look at a single individual and say, ‘Oh yeah, their brain pattern is clearly falling into a pattern that we can say is consistent with lying or consistent with telling the truth,’” he explains. “All you could say is that statistically, when you look at a bunch of people, when they’re lying, they tend to have these patterns more than when they’re telling the truth. So these kinds of things are very useful in research, but not necessarily practically for a specific individual.”

Similarly, he says, when it comes to marketing, marketers want to know the net effect on someone’s behavior. “They want to know how people are going to behave,” he says. “I don’t know that they necessarily care what’s happening in the brain, what’s driving that behavior.”

Other applications include anything with a binary yes-or-no response. So the technologies in which it could potentially be used are limitless. Apart from the lie-detection and marketing arenas, it could also potentially be used in education (testing) and with kids who have disabilities. If we were able to map their brains and know how they would react to a certain situation, a lot of good (and bad) could potentially result from these technologies.

So who’s making your decisions? And can a scientist predict before you how you’re going to react to a certain situation? For now, there’s no clear answer. In a few years, though, we may just be forced to find out.

(Editor’s note: This article is from a past issue of Brain World magazine. If you enjoy this article, please support us with a print or digital subscription!)


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