RELATIONSHIP BETWEEN SKIN CONDUCTANCE RESPONSES AND DECISION MAKING IN THE GAMBLING TASK
Atsunobu, S., The University of Tokyo, Japan
The somatic marker hypothesis (Damasio, Tranel, & Damasio, 1991 In Frontal lobe function and dysfunction 217-229) is a controversial theory asserting that somatic activities covertly guide human decision making. Consistent with the theory, Bechara, Tranel, Damasio, and Damasio (1996 Cerebral Cortex 6 215-225) reported that patients with damage of the ventromedial prefrontal cortex showed irrationally risk-prone performance in the gambling task (a card game in which participants are sequentially asked to choose one card at a time from four decks of cards and are given monetary gain/loss; Bechara, Damasio, Damasio, & Anderson, 1994 Cognition 50 7-15), and that such risk-prone performance was related to the lack of anticipatory skin conductance responses (SCRs). Moreover, Bechara, Damasio, Damasio, and Lee (1999 The Journal of Neuroscience 19 5473-5481) suggested the analogous relationship between decision making and anticipatory SCRs even within the healthy population. In this study, we analyzed in detail SCRs generated during the gambling task using healthy university students as subjects (n=40). Contrary to our prediction, anticipatory SCRs were not observed. However, we found that those who generated lower SCRs after choosing risky decks tended to persist in such risky decisions more than those who generated higher SCRs. Our finding was comparable to the result of amygdala-damaged patients in Bechara et al. (1999) and supported the view that individual differences in decision making were also influenced by somatic activities.