New studies have identified a specific neural circuit in the brains of monkeys that is activated when they postpone acting on a decision. The circuit is thought to keep potential choices brewing in memory even after a decision has already been made.

The brain may continue to consider the options even after a decision is made because that extra consideration may sometimes result in a change of mind – and a possible reward, such as a tastier meal. The researchers said that their findings could offer important insight into the function of neural circuits that drive the brain’s memory and decision-making machinery.
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the researchers conducted experiments in which they required the monkeys to delay their decision. At the same time, the researchers recorded the electrical activity of neurons in a region called the medial premotor cortex—one of the brain regions involved in decision-making and motor choice.

“To our surprise, when the monkeys held the decision for several seconds, what we saw in the activity of these brain cells in the medial premotor cortex is that they were still remembering the sensory information on which the decision was based,” said Romo. “During that time the neurons were recalling the first stimulus, recalling the second, comparing the second against the first, and even reporting in their activity the categorical decision.”