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Imagine you're in line at your favourite bakery, deciding whether to have a doughnut or a tart. You weigh them up, the doughnut wins, and you settle on that. By the time you're at the front of the line, however, only tarts are left. So, you buy one.

These two decisions feel completely different. One is a free decision that involves consideration based on your personal preferences, while the other is a forced decision that involves simply recognizing and picking the only available option. Neuroscientists have long assumed free decisions rely on different processes in the brain compared to forced decisions. But our latest research shows our brains actually make these decisions in surprisingly similar ways.

Decades of research have shown that, to make decisions, our brains gradually gather evidence for each option over time. By measuring electrical brain activity, researchers have identified a brain signal that reflects this accumulation of evidence during simple decisions. Like a loading bar building to 100%, the signal gradually rises to a particular level before a decision is made. Rather than climbing steadily towards one option, the signal fluctuates back and forth between the alternatives. This partly explains why we aren't always consistent with our choices, even when our preferences are stable. This signal has been identified for forced decisions. But what about open-ended choices?

To answer this question, we recorded people's brain activity while they chose between sets of coloured balloons. They viewed either two balloons of different colours to freely choose between, or a single balloon they were forced to pick. For both free and forced decisions, the brain activity unfolded in a strikingly similar way. The signal rose steadily to the same peak level before a choice was made, climbing faster for quick choices and slower for longer ones.

One might assume the brain forms free and forced decisions similarly, suggesting decision-making may be more automatic than it feels. This echoes Benjamin Libet's experiments in the 1980s, which show brain activity begins ramping up before people are even consciously aware of their intention to act. But while the process may be automatic, what the brain is accumulating tells a different story. The evidence it weighs up is drawn entirely from who you are - your preferences, your goals, your experiences. Two people may go through the same neural process and land on 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 really means for a choice to be yours. And the next time you find yourself in line at the bakery, know that your brain has already been quietly gathering evidence toward your baked good of choice, and that choice happens a little faster than you realise.