Brain region helps us learn from our mistakes

To err may be human — but a new Yale study has revealed the brain region that prevents us from making the same mistake twice.

The researchers showed that the medial frontal cortex — a region of the brain directly behind the forehead — spiked in activity after both rats and humans in the study made a mistake. The report is the first to identify the brain region responsible for more cautious behavior after errors and may lead to new treatments for diseases including obesity, OCD and schizophrenia.

In the study, rats and humans received feedback on their performance on a time-estimation task in which humans estimated 1.4 seconds and rats received a reward for releasing a lever before a 600-millisecond window. The study found that after making an error, both humans and rats adjusted their behavior by slowing down their responses, said study author and University of Iowa professor of neurology Nandakumar Narayanan.

Researchers found that in both humans and rats, higher rates of low-frequency brain waves in the medial frontal cortex — measured by EEG in humans and microelectrode arrays in rats — predicted greater post-error slowing.

The researchers also chemically knocked out the medial frontal cortex of rats to investigate whether eliminating the function of the region would prevent the animals from learning from their mistakes. Once the medial frontal cortex was no longer active, the rats stopped adjusting their behavior based on prior errors.

“The findings were highly novel, showing that synchronization between different frontal cortical regions is necessary for adjusting behavior after mistakes,” said Brown University professor of cognitive, linguistic and psychological sciences Michael Frank.

Since error processing is such a fundamental computation, dysfunction in the medial frontal cortex manifests in a range of disorders, said study author and Yale professor of neurobiology Mark Laubach.

The brains of the chronically obese commonly feature weakened connectivity in the neurons in the medial frontal cortex, Laubach said. Without proper error monitoring from the medial frontal cortex, obese individuals may continue to eat excessively despite the harmful effects of their actions.

Activity in the region is too low for individuals with schizophrenia, Laubach said, leading to repetitive behaviors, even if these behaviors have negative consequences. By contrast, the region is too active for those with OCD.

“Hyperactivity, in this case, is a deficiency,” said study author and psychology professor at the University of New Mexico James Cavanagh. “The hyperactive error signal is not being utilized to assist behavior [in OCD patients]. They have an alarm bell ringing but they’re not able to utilize that signal.”

Since the study demonstrated such strong similarities between the error systems in rats and humans, researchers can now use rats to develop drug therapies for humans, Cavanagh said.

The study appeared in the journal Nature Neuroscience and was published online on Oct. 20.

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