The Choice Behavior and Amygdala Activation by Unpleasant Images: Functional Magnetic Resonance Imaging Analysis under Risk and Uncertainty

Abstract

Twenty one healthy and right handed dentists underwent functional magnetic resonance imaging (3T-fMRI) under risk and uncertainty while viewing blocks of unpleasant images and neutral images. This study used the Balloon Analogue Risk Task (BART). The subjects knew the probability of the task under risk and did not know the probability under uncertainty. The left amygdala and the putamen were activated by the unpleasant images during the task under uncertainty. However, the anterior cingulate cortex was activated and amygdala was not activated during the task under risk. These results show that the activity of inhibitory system and amygdala under uncertainty may be different from that in risky situation.