How the brain decides

In making a decision, our brains operate like a bookie's computer, weighing the actions of others in the same way that we learn from our mistakes in order to calculate the odds, according to a recent study. Neuroscientists observing brain activity in a group of volunteers say the results challenge conventional theories about how and where decisions are formed in the brain.

Earlier research on the neural mechanisms of decision-making found that the brain processes two separate streams of data: one is based on our own experience and our record of success or failure in similar circumstances, based on trial and error; the other flows from the fact that we are social animals, and that we are influenced by what others do and say. Most scientists had assumed that the neural underpinning of this second kind of learning was more complex than the first, but the new study suggests that in both functions, the brain uses the same basic computational mechanism.

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