Two brain regions play complementary roles when people stop themselves from blurting out that inappropriate comment or walking into an oncoming car, researchers have found.
The team — which included four researchers at Stanford and one at Yale — used novel computational technology to analyze existing data. They showed that a particular region on the right side of the brain was responsible for detecting the stimulus, for instance, a fast approaching car. A nearby region then effected the inhibitory response, stopping people in their tracks.
“Inhibitory control serves a fundamental function in our daily lives,” said Weidong Cai, research associate at Stanford and lead author of the paper. However, how the two brain regions in question contribute to this inhibition was not well understood until the study was carried out, he said.
This is because both regions are activated when people stop an action, said Yale psychiatry and neurobiology professor Chiang-Shan Li, one of the study’s authors. He added that the insufficient resolution of brain imaging techniques and the variation in the brain activities of subjects added to the challenge.
Srikanth Ryali, one of the Stanford researchers, said the team decided to tackle this problem using a novel algorithm. They found that two regions — the right anterior insula and the right inferior frontal cortex — had distinct functions in inhibitory control, with the former acting as a sensor and the latter as an effector.
“This is a nice piece of science that advances our understanding of inhibitory control,” said University of California at San Diego psychology professor Adam Aron, who works in the field of cognitive neuroscience and did not contribute to the study.
Such work has important implications because many psychiatric disorders stem from impaired inhibitory control, said Vinod Menon, Stanford psychiatry professor and director of the school’s Cognitive and Systems Neuroscience Laboratory, as well as the paper’s senior author. These problems, he explained, include attention deficit hyperactivity disorder and obsessive-compulsive disorder.
Understanding the mechanism of this inhibition could lead to improvements in the diagnosis and treatment of these disorders, Menon said.
Menon also highlighted how the team’s computational methods could be applied to understand impairments in brain function beyond inhibitory control.
Citing neurodegenerative disease as an example, he explained that researchers would be able to apply the team’s methods to identify the brain regions with dysfunction and whether this dysfunction lies in sensing, integrating or executing. The hope, he said, is that such research will eventually lead to better outcomes for patients.
Menon said that the team was able to replicate its findings in an independent data set thanks to the Yale researchers’ willingness to share their data, he said.
“It definitely improves research quality,” Menon said. “Replication is very important in science, and this collaboration gives us confidence that our findings are robust,” he added.
The study drew data from 70 published studies and a separate Stanford dataset in addition to the Yale data.