The following essay is reproduced with permission from 
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Imagine standing in line at your favorite bakery and deciding whether you want to eat a donut or a pie. You weigh them, the donut wins and you decide on that.
However, when you’re on the front lines, all that’s left is tartlets. So you buy one.
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These two decisions seem completely different. One involves deliberation based on our unique and personal preferences, while the other involves simply recognizing and choosing the only available option.
But our latest research published in the journal Imaging Neuroscience shows that our brains make these decisions in surprisingly similar ways.
What exactly is free choice?
When we make free decisions, we recognize that there are several options, evaluate them, and commit to choosing one based on something internal: our preferences, our values, and our goals.
Forced decisions are different. There is only one possible outcome, and our job is simply to identify the option and take it.
Because free decisions seem so closely tied to who we are, neuroscientists have long assumed that they rely on different brain processes than forced decisions. A few brain imaging studies support this, showing different patterns of neuronal activity distributed across the brain.
However, knowing where free choices occur in the brain tells us little about how they are formed – and whether this process is different from forced decisions.
How does the brain make a decision?
Decades of research showed that, to make decisions, our brains gradually gather evidence for each option over time.
Think of it like a judge evaluating the facts of a case. Once enough evidence has been accumulated in favor of one party, a verdict is rendered. For some types of decisions, this happens very quickly (within a few hundred milliseconds), making it seem like the choice is coming to you.
By measuring the electrical activity of the brain, researchers identified a brain signal that reflects this accumulation of evidence during simple decisions, such as judging whether a traffic light is red or green.
Like a loading bar reaching 100%, the signal gradually rises to a particular level before a decision is made. Because the action of neurons in the brain is noisy, this decision-making process also occurs noisyly: rather than climbing steadily toward one option, the signal fluctuates between alternatives.
This partly explains why we are not always consistent in our choices: even when our preferences are stable, some days we opt for the pie and others for the donut.
This signal has been identified for forced decisions with a clear and correct response. But what about open-ended choices – shaped not just by what’s in front of us, but by something internal like personal preferences or goals?
Tracing the brain signals of decision formation
To answer this question, we recorded people’s brain activity as they chose between sets of colored balloons. They either saw two different colored balloons to freely choose between, or a single balloon that they were forced to choose.
They pressed a button at the moment they made their choice, and we tracked the course of brain activity before that moment.
Whether they were free or forced decisions, brain activity occurred in a very similar way. Like a loading bar, it steadily climbed to the same maximum level just before a choice was made. When people decided quickly, the signal grew faster. When they took longer, it increased more slowly.
This is exactly what you would expect if the brain tracked and evaluated evidence over time, rather than simply reacting to a decision at the last moment.
Does this mean that our free choices are not truly free?
From this finding, one could assume that the brain makes free and forced decisions equally, suggesting that decision-making in the brain might be more automatic than it appears.
This echoes famous experiments of neuroscientist Benjamin Libet in the 1980s. He and his colleagues discovered that brain activity begins to intensify before people are even aware of their intention to act, suggesting that the brain has already begun to make a decision before the person consciously realizes that they have made a choice.
But while the process may be automatic, what the brain accumulates tells a different story. The evidence it evaluates is drawn entirely from who you are: your preferences, your goals, your experiences. Two people can go through the same neural process and arrive at the same choice, and yet arrive there for completely different reasons.
So rather than asking whether our choices are truly free, perhaps the better question is what it actually means to have a choice. And the next time you’re waiting in line at the bakery, know that your brain has already quietly gathered evidence about the pastry of your choice, and that choice is happening a little faster than you think.
This article was originally published on The conversation. Read the original article.
