Ishii Hironori, Tsutsui Ken-Ichiro, Iijima Toshio
Division of Systems Neuroscience, Tohoku University Graduate School of Life Sciences.
Brain Nerve. 2013 Aug;65(8):965-72.
Risk taking can lead to ruin, but sometimes, it can also provide great success. How does our brain make a decision on whether to take a risk or to play it safe? Recent studies have revealed the neural basis of risky decision making. In this review, we focus on the role of the anterior insular cortex (AIC) in risky decision making. Although human imaging studies have shown activations of the AIC in various gambling tasks, the causal involvement of the AIC in risky decision making was still unclear. Recently, we demonstrated a causality of the AIC in risky decision making by using a pharmacological approach in behaving rats-temporary inactivation of the AIC decreased the risk preference in gambling tasks, whereas temporary inactivation of the adjacent orbitofrontal cortex (OFC) increased the risk preference. The latter finding is consistent with a previous finding that patients with damage to the OFC take abnormally risky decisions in the Iowa gambling task. On the basis of these observations, we hypothesize that the intact AIC promotes risk-seeking behavior, and that the AIC and OFC are crucial for balancing the opposing motives of whether to take a risk or avoid it. However, the functional relationship between the AIC and OFC remains unclear. Future combinations of inactivation and electrophysiological studies may promote further understanding of risky decision making.
冒险可能导致毁灭，但有时也能带来巨大的成功。我们的大脑是如何决定是冒险还是谨慎行事的呢？最近的研究揭示了风险决策的神经基础。在这篇综述中，我们重点关注前岛叶皮质（AIC）在风险决策中的作用。尽管人类成像研究显示在各种赌博任务中AIC会被激活，但AIC在风险决策中的因果关系仍不明确。最近，我们通过对行为大鼠采用药理学方法证明了AIC在风险决策中的因果关系——暂时使AIC失活会降低赌博任务中的风险偏好，而暂时使相邻的眶额皮质（OFC）失活则会增加风险偏好。后一发现与之前的一项研究结果一致，即患有眶额皮质损伤的患者在爱荷华赌博任务中会做出异常冒险的决策。基于这些观察结果，我们推测完整的AIC会促进冒险行为，并且AIC和OFC对于平衡冒险或避免冒险的相反动机至关重要。然而，AIC和OFC之间的功能关系仍不明确。未来失活研究与电生理研究的结合可能会促进对风险决策的进一步理解。
