Scientists Find Error-Recognition Area of Brain

N E W   Y O R K, Dec. 13 -- Sometimes you stop in mid-action, certain you’ve made a mistake. How does your brain know? Where does that message come from?

This week neuroscientists got a little bit closer to answering that question when they isolated the “oops” center in monkeys’ brains. Researchers at Vanderbilt University in Nashville, Tenn., led by psychology professor Jeffrey Schall, say they have located the specific set of neurons in the brain where error recognition occurs.

The area may be part of a larger system that has evolved in the brain to control its own activity as it makes decisions, corrects errors and overrides habitual responses.

Using monkeys in their experiment allowed the Vanderbilt team to monitor brain activity at a level of resolution that is not possible in humans. Schall believes the findings, published this week in the journal Nature, have important implications for mental and neurological illnesses as well as a fundamental human question — do we really have free will?

Monkey See, Monkey Err

The researchers sat a group of macaque monkeys in front of computer screens, monitoring their gaze with an eye-tracking system. A spot appeared on the center of each screen. When the monkey’s gaze was fixed on it, the spot disappeared and a new one appeared on the periphery of the screen.

If the monkey shifted its gaze to the peripheral spot, it was rewarded with juice. During some of the trials, the central spot reappeared while the monkey was preparing to shift its gaze to the peripheral spot, in which case monkeys who canceled the planned eye movement and kept their gaze on the center were rewarded.

As the monkeys performed the task, researchers also monitored neuron activity in a part of the brain called the supplementary eye field. They found three types of neurons in the area. One type acts when the monkey realizes it has made a correct decision and will receive a reward, the second reacts when the monkey becomes cognizant of its mistake, and the third responds when the brain receives conflicting instructions.