Department of Psychology, University of Southern California, Los Angeles, CA 90089-1061, USA.
Neuroimage. 2010 Apr 1;50(2):709-16. doi: 10.1016/j.neuroimage.2009.12.097. Epub 2010 Jan 4.
Risky decision-making is significantly affected by homeostatic states associated with different prior risk experiences, yet the neural mechanisms have not been well understood. Using functional MRI, we examined how gambling decisions and their underlying neural responses were modulated by prior risk experiences, with a focus on the insular cortex since it has been implicated in interoception, emotion and risky decision-making. Fourteen healthy young participants were scanned while performing a gambling task that was designed to simulate daily-life risk taking. Prior risk experience was manipulated by presenting participants with gambles that they were very likely to accept or gambles that they were unlikely to accept. A probe gamble, which was sensitive to individual's risk preference, was presented to examine the effect of prior risk experiences (Risk vs. Norisk) on subsequent risky decisions. Compared to passing on a gamble (Norisk), taking a gamble, especially winning a gamble (Riskwin), was associated with significantly stronger activation in the insular and dorsal medial prefrontal cortices. Decision making after Norisk was more risky and more likely to recruit activation of the insular and anterior cingulate cortices. This insular activity during decision making predicted the extent of risky decisions both within- and across-subjects, and was also correlated with an individual's personality trait of urgency. These findings suggest that the insula plays an important role in activating representations of homeostatic states associated with the experience of risk, which in turn exerts an influence on subsequent decisions.
风险决策受到与不同先前风险体验相关的体内平衡状态的显著影响，但神经机制尚未得到很好的理解。使用功能磁共振成像，我们研究了先前的风险体验如何调节赌博决策及其潜在的神经反应，重点关注脑岛，因为它与内脏感知、情绪和风险决策有关。14 名健康的年轻参与者在执行赌博任务时接受了扫描，该任务旨在模拟日常生活中的风险承担。通过向参与者呈现他们很可能接受的赌博或他们不太可能接受的赌博来操纵先前的风险体验。一个探测赌博，它对个体的风险偏好敏感，被用来检查先前的风险体验（风险与非风险）对随后的风险决策的影响。与放弃赌博（非风险）相比，参与赌博，特别是赢得赌博（风险赢），与脑岛和背内侧前额叶皮层的显著更强激活有关。非风险后进行的决策风险更大，更有可能激活脑岛和前扣带皮层。这种决策过程中的脑岛活动既可以在个体内部预测风险决策的程度，也可以在个体之间预测风险决策的程度，并且还与个体的紧迫感人格特质相关。这些发现表明，脑岛在激活与风险体验相关的体内平衡状态的表示方面发挥着重要作用，进而对随后的决策产生影响。
