Researchers discover area of brain that "controls" cognitive control
study holds promise for schizophrenia and obsessive-compulsive disorder patients

brain fMRI showing ACC (yellow and red) and PFC (red and green)

For years, researchers have attempted to explain and identify what controls a person's cognitive function. Previous research indicated that the prefrontal cortex (PFC), located in the front of the brain, implemented cognitive control, but it has been unclear how the PFC was regulated or how the PFC "knew" it needed to become active to exert control. A team of researchers has discovered that the anterior cingulated cortex (ACC), found in the middle of the brain, detects conflict, which leads to initiation of cognitive control in the PFC. The findings were released in the February 13, 2004, issue of Science.

Cognitive control, according to John Kerns, assistant professor of Psychological Sciences, can involve driving a car while talking on a cell phone or crossing a busy street in London. These situations require a need to pay attention to the right information at the right time. Cognitive control also helps overcome highly practiced and automatic behavior, such as looking to the left when traffic in London comes from the right.

A team led by Kerns determined through a series of tests that the ACC, implements a conflict-monitoring function that directly leads to cognitive control. Kerns believes this finding will have a significant impact in the medical field, especially with people suffering from schizophrenia, who have an underactive ACC that may result in disorganized and chaotic behavior, or people with obsessive-compulsive disorder, who have an overactive ACC that may result in the incorrect detection of conflict when it does not exist.

"This discovery will bring to light why some of these failures in the brain take place for certain people, who might over- or under-use their cognitive control," Kerns said. "We hope to improve the quality of life for these individuals. It also could explain why people experience routine cognitive failures, such as forgetting why they went from one room to the next or getting easily distracted."

Kerns and his team examined 23 individuals using a test called the Stroop color-naming task. In this test, words denoting colors, such as red or green, were presented in a variety of different colors (e.g., the word RED in green ink). The person was instructed to report the physical color or the color the word denotes. Most people found it difficult to respond correctly when the physical color of the word is different from the color it denoted. While the individuals were taking the test, their brains were undergoing magnetic resonance imaging, which allowed the team to view the brain in action.

The researchers found that when the words presented to the subjects were in a different color from the color the words denoted, the conflict induced an increase in ACC activity. Shortly thereafter, the increase in ACC activity was followed by an increase in activity in the PFC due to the recruitment of cognitive control during the first exercise, resulting in improved performance.

Brief bio

Additional links:

John Kerns
Department of Psychological Sciences

Science article abstract

Research Team
Jonathan D. Cohen, University of Princeton
Angus MacDonald III, University of Minnesota
Raymond Y. Cho, University of Pittsburgh
V. Andrew Stenger, University of Pittsburgh
Cameron S. Carter, University of Califonia, Davis

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