Tuesday, 30 May 2006

Brain dread

It makes time slow down when you want it to go fast, and it keeps turning your mind back to the very thing you want to forget – dread is a most unpleasant emotion. Now Gregory Berns (pictured) and colleagues at Emory University School of Medicine think they’ve found where dread is represented in the brain.

Berns’ team scanned the brains of 32 participants while applying electric shocks to their feet. Dread was induced in the participants by giving them information before each shock that told them how powerful it would be and how long until it would be applied (e.g. “60 per cent strength in 27 seconds”).

Compared with the 23 participants classified as mild dreaders, the researchers found the nine participants classified as extreme dreaders exhibited more activity in their caudal anterior cingulate cortex, a part of the brain’s pain ‘matrix’ that is known to be involved in paying attention to the location of pain. However, levels of activity in the amygdala, a region associated with fear and anxiety, did not differ between the two groups.

“Taken together, the anatomical locations of dread responses suggest that the subjective experience of dread that ultimately drives an individual’s behaviour comes from the attention devoted to the expected physical response and not simply a fear or anxiety response”, the researchers wrote. In other words, dread can probably be reduced by distracting yourself from what it is you're dreading.

The participants were classified as mild or extreme dreaders based on their pattern of behaviour in a different part of the experiment in which they had to choose between more pain sooner versus less pain later (i.e. after a longer period of dread). The extreme dreaders sometimes chose more pain sooner, and they also reported finding the longer waits more unpleasant than trials in which the electric shock came sooner.

“The neurobiological mechanisms governing dreading behaviour may hold clues for both better pain management and improvements in public health”, the researchers concluded.
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Berns, G.S., Chappelow, J., Cekic, M., Zink, C.F., Pagnoni, G. & Martin-Skurski, M.E. (2006). Neurobiological substrates of dread. Science, 312, 754-758.

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

1 comment:

  1. Completing ethics compliance procedures for this project must have been a bastard.

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