The dread associated with the anticipation of a painful event, such as a visit to the dentist, activates regions of the brain involved in processing pain stimuli, according to a study published in the cuurent issue of Science.
Gregory Berns, a neuroscientist at Emory University School of Medicine in Atlanta, Georgia, led a research team which investigated the brain activity of 32 volunteers as they waited to receive electric shocks on their feet.
Participants in the experiment were asked to choose the intensity of the shock they would receive and when they would receive it, and then plit into two groups according to the decisions they made.
Most of the participants were 'mild dreaders'; that is, they chose to receive a small electric shock later rather than sooner. In contrast, 9 participants dreaded the shock so much that they decided to receive a larger electric shock sooner, to get it 'over and done with'. These were characterized as 'extreme dreaders'.
Using functional magnetic resonance (fMRI), Berns and his team have shown that the dread experienced by the volunteers as they waited for their shocks is correlated to activity in the areas of the cerebral cortex which process pain. The fMRI scans carried out as the volunteers waited for their shocks revealed that these brain areas were more active in the 9 'extreme dreaders' than in the 'mild dreaders'.
Given the choice of waiting for an unpleasant event or experiencing it quickly, most people choose the latter. Decisions such as this, which involve a trade-off between two outcomes which could occur at different times, are called intertemporal choices. Neuroeconomics uses a combination of methods and theories from neuroscience, psychology and economics to try and determine how such decisions are reached.
"This paper gives a much richer understanding of intertemporal choice," says George Loewenstein, a behavioral economist at the Carnegie Mellon University in Pittsburgh, Pennsylvania. Knowledge of the motivation behind choices will provide a better understanding of how people make life-changing decisions.