The Neurobiology of Dread

A team of Emory University neuroscientists tried to understand the reasons why we tend to deal with dreadful decisions as quickly as possible. Using functional magnetic resonance imaging (fMRI), the team led by Gregory Berns, MD, PhD, has found the areas of the brain that are activated when someone experiences dread:

“Most people don’t like waiting for an unpleasant outcome, and want to get it over with as soon as possible,” explains Dr. Berns, an associate professor in the Department of Psychiatry and Behavioral Sciences at Emory University School of Medicine. “The only explanation for this is that the dread of having something hanging over your head is worse than the thing that you are dreading. It is a commonplace experience, but standard economic models of decision-making don’t deal with this issue. So, we decided to take a biological approach and see what happens in the brain that might cause people to make such rash decisions.”
Each of the participants in the study was screened to determine their maximal pain threshold. While in the MRI scanner, participants underwent a series of 96 shocks. Before each shock, they were told how painful the shock would be (as a percent of their threshold) and how long they would have to wait for it. After the procedure, they were given the opportunity to choose between different intensity-delay combinations. The choice was always between more pain sooner or less pain later. The degree to which individuals chose more voltage sooner just to get a trial over was an indication of the dread they experienced from waiting. A total of 32 participants took part. Most of the participants preferred to speed up the waiting period and were deemed “mild dreaders”, but 28% dreaded so much that they were willing to take more pain just to avoid waiting. Berns called them “extreme dreaders.”
The scans showed that brain activity related to dread was localized in the areas of the brain associated with pain. Dread was found in the parts of the pain network linked to attention. This is important because it suggests that dread is not as simple as fear or anixiety, which are emotions controlled by different brain regions.
The findings also showed that the mild and extreme dreaders had different patterns of brain activity. The extreme dreaders had more activity in the attentional parts of the pain matrix, and this activity was seen much earlier in each trial compared to the mild dreaders.
“Taken together, the anatomical locations of dread responses suggest that the subjective experience of dread comes from the attention devoted to the expected physical response, and not simply a fear or anxiety response,” explains Dr. Berns. “The key factor seems to be that extreme dreaders devoted more attention toward the part of their body that was about to be shocked. This means that dread is not quite the same as fear or anxiety. These findings underscore the very real nature of dread.”

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