Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, UK.
Brain Behav. 2023 May;13(5):e2978. doi: 10.1002/brb3.2978. Epub 2023 Apr 5.
We assess risks differently when they are explicitly described, compared to when we learn directly from experience, suggesting dissociable decision-making systems. Our needs, such as hunger, could globally affect our risk preferences, but do they affect described and learned risks equally? On one hand, decision-making from descriptions is often considered flexible and context sensitive, and might therefore be modulated by metabolic needs. On the other hand, preferences learned through reinforcement might be more strongly coupled to biological drives.
Thirty-two healthy participants (females: 20, mean age: 25.6 ± 6.5 years) with a normal weight (Body Mass Index: 22.9 ± 3.2 kg/m ) were tested in a within-subjects counterbalanced, randomized crossover design for the effects of hunger on two separate risk-taking tasks. We asked participants to choose between two options with different risks to obtain monetary outcomes. In one task, the outcome probabilities were described numerically, whereas in a second task, they were learned.
In agreement with previous studies, we found that rewarding contexts induced risk-aversion when risks were explicitly described (F = 55.01, p < .0001, η = .64), but risk-seeking when they were learned through experience (F = 10.28, p < .003, η = .25). Crucially, hunger attenuated these contextual biases, but only for learned risks (F = 8.38, p < .007, η = .21).
The results suggest that our metabolic state determines risk-taking biases when we lack explicit descriptions.
与直接从经验中学习相比，当我们明确描述风险时，我们会以不同的方式评估风险，这表明存在可分离的决策系统。我们的需求，如饥饿感，可能会全局影响我们的风险偏好，但它们是否会以相同的方式影响描述风险和学习风险？一方面，从描述中进行决策通常被认为是灵活的，并且对上下文敏感，因此可能会受到代谢需求的调节。另一方面，通过强化学习的偏好可能与生物驱动因素更紧密地耦合。
32 名健康参与者（女性：20 名，平均年龄：25.6 ± 6.5 岁）体重正常（体重指数：22.9 ± 3.2 kg/m ），采用基于个体的、平衡随机交叉设计，在两种不同的风险承担任务中测试饥饿对风险偏好的影响。我们要求参与者在两个不同风险的选项之间进行选择，以获得货币收益。在一个任务中，结果概率是用数字描述的，而在第二个任务中，它们是通过经验学习的。
与之前的研究一致，我们发现，当风险被明确描述时，奖励环境会诱导风险规避（F = 55.01，p <.0001，η =.64），但当它们通过经验学习时，会诱导风险寻求（F = 10.28，p <.003，η =.25）。至关重要的是，饥饿会削弱这些情境偏见，但仅针对学习风险（F = 8.38，p <.007，η =.21）。
研究结果表明，当我们缺乏明确的描述时，我们的代谢状态决定了风险承担偏好。
