Recent research at the Medical Center finally offers a physiological explanation of how intense emotion interferes with concentration.
Using magnetic resonance imaging to map areas of activity in the brains of human subjects, researchers determined that emotional and routine functions of attention are processed through the brain in two parallel streams, each in a constant fight for the brain's resources.
"There exists a tug-of-war in the frontal lobes between attentional and emotional activity," said Dr. Kevin LaBar, assistant professor at the Center for Cognitive Neuroscience and author of a new study on the correlation. "Since the brain has a limited amount of processing resources, you are easily distracted by emotional events.... The brain seems to switch between attention and emotion."
The results, published in the Aug. 20 issue of The Proceedings of the National Academy of Sciences, may lead to new treatments for a variety of neurological disorders like depression, post-traumatic stress disorder and attention deficit disorder-diseases that have been linked to malfunctions in the processing of emotional stimuli.
"Depressed people have sad thoughts, intrusive thoughts that get them off task," LaBar said. "The idea is maybe we can help them not be so distracted."
After placing subjects inside an MRI machine and giving them video goggles for the tests, scientists showed the subjects a series of circles and squares and asked them to keep a running count of the circles; this was intended to model normal attentional activity. Interspersed with the circles and squares was a series of complex scenes that were either neutral or emotionally sensitive.
The emotional material was found to affect concentration more than mere distraction.
"When distracting stimuli was on, the attentional activity was suppressed, but [the subjects] responded more to the emotional stimuli," LaBar said.
MRI analysis also concluded how the activity was coordinated within the brain. "What we found is that attentional targets are activated in a superior network in the brain... and distracting stimuli in a ventral part of the brain," LaBar said.
In addition, the researchers determined that an important section of the frontal lobe called the anterior cingulate was the only brain area that responded to both types of stimuli, suggesting it acts as the integrating center for all such cognition.
The researchers plan to repeat the experiment with depressed patients to see precisely how brain function goes awry in cognitive disorders, which will aid in the development of drug treatments and other therapies.
"Whenever you understand a process in the brain, it allows you to understand how to treat it," said Cynthia Kuhn, a professor of pharmacology and an expert on neuropharmacology. "As far as developing treatments, an imaging study is incredibly powerful."
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