How the brain says 'oops!'

 Researchers from Cedars-Sinai's Center for Neural Science and Medicine and Department of Neurosurgery have uncovered how signals from a group of neurons in the brain's frontal lobe simultaneously give humans the flexibility to learn new tasks -- and the focus to develop highly specific skills. Their research, published today in the peer-reviewed journal Science, provides a fundamental understanding of performance monitoring, an executive function used to manage daily life.

The study's key finding is that the brain uses the same group of neurons for performance feedback in many different situations -- whether a person is attempting a new task for the first time or working to perfect a specific skill.

"Part of the magic of the human brain is that it is so flexible," said Ueli Rutishauser, PhD, professor of Neurosurgery, Neurology, and Biomedical Sciences, director of the Center for Neural Science and Medicine, the Board of Governors Chair in Neurosciences and senior author of the study. "We designed our study to decipher how the brain can generalize and specialize at the same time, both of which are critical for helping us pursue a goal."

Performance monitoring is an internal signal, a kind of self-generated feedback, that lets a person know they have made a mistake. One example is the person who realizes they drove past an intersection where they should have turned. Another example is the person who says something in conversation and recognizes as soon as the words are out of their mouth that what they just said was inappropriate.

"That 'Oh, shoot' moment, that 'Oops!' moment, is performance monitoring kicking in," said Zhongzheng Fu, PhD, a postdoctoral researcher in the Rutishauser Laboratory at Cedars-Sinai and first author of the study.

These signals help improve performance on future attempts by passing information to areas of the brain that regulate emotions, memory, planning and problem-solving. Performance monitoring also helps the brain adjust its focus by signaling how much conflict or difficulty was encountered during the task.

"So an 'Oops!' moment might prompt someone to pay closer attention the next time they chat with a friend or plan to stop at the store on the way home from work," said Fu.

To see performance monitoring in action, investigators recorded the activity of individual neurons in the medial frontal cortex of study participants. The participants were epilepsy patients who, as part of their treatment, had electrodes implanted in their brains to help locate the focus of their seizures. Specifically, these patients had electrodes implanted in the medial frontal cortex, a brain region known to play a central role in performance monitoring.

The team asked participants to perform two commonly used cognitive tests.

In the Stroop task, which pits reading against color naming, participants viewed the written name of a color, such as "red," printed in ink of a different color, such as green, and were asked to name the ink color rather than the written word.

"This creates conflict in the brain," Rutishauser said. "You have decades of training in reading, but now your goal is to suppress that habit of reading and say the color of the ink that the word is written in instead."

In the other task, the Multi-Source Interference Task (MSIT), which involves recognizing numerals, participants saw three numerical digits on screen, two the same and the other unique -- for example, 1-2-2. The subject's task was to press the button associated with the unique number -- in this case, "1" -- resisting their tendency to press "2" because that number appears twice.

"These two tasks serve as a strong test of how self-monitoring is engaged in different scenarios involving different cognitive domains," Fu said.

Source: ScienceDaily