An fMRI Study of Risk-Taking Following Wins and Losses: Implications for the Gambler';s Fallacy?

作者：Xue Gui^*; Lu Zhonglin; Levin Irwin P; Bechara Antoine

来源：Human Brain Mapping, 2011, 32(2): 271-281.

DOI：10.1002/hbm.21015

• amygdala
• decision making
• emotion
• frontal cortex
• functional MRI
• gambler'
• s fallacy
• orbitofrontal cortex
• reinforcement learning
• striatum

Human decision-making involving independent events is often biased and affected by prior outcomes. Using a controlled task that allows us to manipulate prior outcomes, the present study examined the effect of prior outcomes on subsequent decisions in a group of young adults. We found that participants were more risk-seeking after losing a gamble (riskloss) than after winning a gamble (riskwin), a pattern resembling the gambler';s fallacy. Functional MRI data revealed that decisions after riskloss were associated with increased activation in the frontoparietal network, but decreased activation in the caudate and ventral striatum. The increased risk-seeking behavior after a loss showed a trend of positive correlation with activation in the frontoparietal network and the left lateral orbitofrontal cortex but a trend of negative correlation with activation in the amgydala and caudate. In addition, there was a trend of positive correlation between feedback-related activation in the left lateral frontal cortex and subsequent increased risk-seeking behavior. These results suggest that a strong cognitive control mechanism but a weak affective decision-making and reinforcement learning mechanism that usually contribute to flexible, goal-directed decisions can lead to decision biases involving random events. This has significant implications for our understanding of the gambler';s fallacy and human decision making under risk. Hum Brain Mapp 32: 271-281, 2011.

• 出版日期2011-2