Glass half full or half empty? What you see may depend in part on the size of your orbitofrontal cortex. Optimistic people also tend to be less anxious, research finds. Credit: Graphic by Julie McMahon
A new study finds healthy adults who have larger OFCs tend to be more optimistic and less anxious. Anxiety disorders afflict roughly 44 million people in the U.S. These disorders disrupt lives and cost an estimated $42-$47 billion annually.
The orbitofrontal cortex, a brain region located just behind the eyes, is known to play a role in anxiety. The OFC integrates intellectual and emotional information and is essential to behavioral regulation. Previous studies have found links between the size of a person’s OFC and his or her susceptibility to anxiety. For example, in a well-known study of young adults whose brains were imaged before and after the colossal 2011 earthquake and tsunami in Japan, researchers discovered that the OFC actually shrunk in some study subjects within 4 months of the disaster. Those with more OFC shrinkage were likely to also be diagnosed with PTSD, the researchers found.
Other studies have shown that more optimistic people tend to be less anxious, and that optimistic thoughts increase OFC activity.
The team hypothesized a larger OFC might act as a buffer against anxiety in part by boosting optimism.
METHOD: They collected MRIs of 61 healthy young adults and analyzed the structure of a number of regions in their brains, including the OFC. They calculated the volume of gray matter in each brain region relative to the overall volume of the brain. The study subjects also completed tests that assessed optimism and anxiety, depression symptoms, and positive (enthusiastic, interested), negative (irritable, upset) affect.
RESULT: statistical analysis and modeling revealed that a thicker orbitofrontal cortex on the left side of the brain corresponded to higher optimism and less anxiety. The model also suggested that optimism played a mediating role in reducing anxiety in those with larger OFCs. Further analyses ruled out the role of other positive traits in reducing anxiety, and no other brain structures appeared to be involved in reducing anxiety by boosting optimism.
“We wanted to know: If we are consistently optimistic about life, would that leave a mark in the brain?” Florin Dolcos said future studies should test whether optimism can be increased and anxiety reduced by training people in tasks that engage the orbitofrontal cortex, or by finding ways to boost optimism directly. “If you can train people’s responses, the theory is that over longer periods, their ability to control their responses on a moment-by-moment basis will eventually be embedded in their brain structure,” he said. https://news.illinois.edu/blog/view/6367/251435
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