Max Planck University College London Centre for Computational Psychiatry and Ageing Research, London WC1B 5EH, United Kingdom;
Wellcome Centre for Human Neuroimaging, University College London, London WC1N 3BG, United Kingdom.
Proc Natl Acad Sci U S A. 2019 Sep 10;116(37):18732-18737. doi: 10.1073/pnas.1900872116. Epub 2019 Aug 26.
Human behavior is surprisingly variable, even when facing the same problem under identical circumstances. A prominent example is risky decision making. Economic theories struggle to explain why humans are so inconsistent. Resting-state studies suggest that ongoing endogenous fluctuations in brain activity can influence low-level perceptual and motor processes, but it remains unknown whether endogenous fluctuations also influence high-level cognitive processes including decision making. Here, using real-time functional magnetic resonance imaging, we tested whether risky decision making is influenced by endogenous fluctuations in blood oxygenation level-dependent (BOLD) activity in the dopaminergic midbrain, encompassing ventral tegmental area and substantia nigra. We show that low prestimulus brain activity leads to increased risky choice in humans. Using computational modeling, we show that increased risk taking is explained by enhanced phasic responses to offers in a decision network. Our findings demonstrate that endogenous brain activity provides a physiological basis for variability in complex human behavior.
人类行为是惊人多变的，即使在相同的环境下面对同样的问题也是如此。一个突出的例子就是冒险决策。经济理论难以解释为什么人类如此不一致。静息态研究表明，大脑活动的持续内源性波动会影响低水平的感知和运动过程，但尚不清楚内源性波动是否也会影响包括决策制定在内的高级认知过程。在这里，我们使用实时功能磁共振成像，测试了多巴胺能中脑（包括腹侧被盖区和黑质）中的血氧水平依赖（BOLD）活动的内源性波动是否会影响冒险决策。我们发现，低刺激前大脑活动会导致人类增加冒险选择。使用计算模型，我们表明，风险承担的增加可以通过决策网络中对报价的相位反应增强来解释。我们的研究结果表明，内源性大脑活动为复杂人类行为的可变性提供了生理基础。
