Vita-Salute San Raffaele University, 20132 Milan, Italy.
J Neurosci. 2013 Sep 4;33(36):14307-17. doi: 10.1523/JNEUROSCI.0497-13.2013.
Decision making under risk entails the anticipation of prospective outcomes, typically leading to the greater sensitivity to losses than gains known as loss aversion. Previous studies on the neural bases of choice-outcome anticipation and loss aversion provided inconsistent results, showing either bidirectional mesolimbic responses of activation for gains and deactivation for losses, or a specific amygdala involvement in processing losses. Here we focused on loss aversion with the aim to address interindividual differences in the neural bases of choice-outcome anticipation. Fifty-six healthy human participants accepted or rejected 104 mixed gambles offering equal (50%) chances of gaining or losing different amounts of money while their brain activity was measured with functional magnetic resonance imaging (fMRI). We report both bidirectional and gain/loss-specific responses while evaluating risky gambles, with amygdala and posterior insula specifically tracking the magnitude of potential losses. At the individual level, loss aversion was reflected both in limbic fMRI responses and in gray matter volume in a structural amygdala-thalamus-striatum network, in which the volume of the "output" centromedial amygdala nuclei mediating avoidance behavior was negatively correlated with monetary performance. We conclude that outcome anticipation and ensuing loss aversion involve multiple neural systems, showing functional and structural individual variability directly related to the actual financial outcomes of choices. By supporting the simultaneous involvement of both appetitive and aversive processing in economic decision making, these results contribute to the interpretation of existing inconsistencies on the neural bases of anticipating choice outcomes.
风险下的决策需要预期未来的结果，通常导致对损失的敏感性大于对收益的敏感性，这种现象被称为损失厌恶。之前关于选择-结果预期和损失厌恶的神经基础的研究结果不一致，表现为对收益的激活和对损失的去激活的双向中脑边缘反应，或者杏仁核在处理损失方面的特定参与。在这里，我们关注损失厌恶，旨在解决选择-结果预期神经基础的个体差异。56 名健康的人类参与者在接受或拒绝 104 个混合赌博时，有 50%的机会获得或失去不同数量的钱，同时用功能磁共振成像（fMRI）测量他们的大脑活动。我们报告了在评估风险赌博时双向和收益/损失特异性的反应，杏仁核和后岛特别跟踪潜在损失的幅度。在个体水平上，损失厌恶既反映在边缘 fMRI 反应中，也反映在结构杏仁核-丘脑-纹状体网络中的灰质体积中，其中介导回避行为的“输出”中央杏仁核核团的体积与货币表现呈负相关。我们得出结论，结果预期和随之而来的损失厌恶涉及多个神经系统，表现出与选择实际财务结果直接相关的功能和结构个体差异。通过支持在经济决策中同时涉及食欲和厌恶处理，这些结果有助于解释关于预期选择结果的神经基础的现有不一致性。
