Human beings are more aroused by rewards they actively earn than by rewards they acquire passively, according to brain imaging research by scientists at Emory University School of Medicine. Results of the study, led by first author Caroline F. Zink and principal investigator Gregory S. Berns, MD, PhD, of Emorys Department of Psychiatry and Behavioral Sciences, are published in the May 13 issue of the journal Neuron.
The Emory scientists used functional magnetic resonance imaging (fMRI) to measure brain activity in the striatum, which is a part of the brain previously associated with reward processing and pleasure. Although other experiments have studied and noted brain activity associated with rewards, until now these studies have not distinguished between the pleasurable effects of receiving a reward and the "saliency" or importance of the reward.
Study volunteers in the Emory experiment were asked to play a simple target-detection computer game. During the game, a money bill appeared occasionally and automatically dropped into a bag of money on the screen. The participant was given the amount of money that dropped in the bag at the end of the game, but because receiving the money had nothing to do with their performance on the computer game, it was not particularly arousing or salient to them. In another version of the game, a money bill occasionally appeared on the screen and the participant had to momentarily interrupt the target detection game and push a button to make the bill drop into the bag. In this case, whether or not the participant received the money did depend on their performance, which made the appearance of the money bill more salient to them. In yet another version, participants played the same computer game except the bag on the screen did not appear to have money in it and a blank "blob" drop!
ped into the bag instead of money.
The investigators performed fMRI on the subjects while they were playing the game, pPage: 1 2 Related medicine news :1
Contact: Holly Korschun
Emory University Health Sciences Center
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