Neuropsychopharmacology and Biopsychology Unit, Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology, University of Vienna, Austria; Department of Clinical and Movement Neurosciences, University College London, London, UK; Wellcome Centre for Human Neuroimaging, University College London, London, UK.
Biological Psychology of Decision Making, Institute of Experimental Psychology, Heinrich Heine University Düsseldorf, Germany.
Horm Behav. 2021 Aug;134:105022. doi: 10.1016/j.yhbeh.2021.105022. Epub 2021 Jul 14.
The sex hormone estradiol is hypothesized to play a key role in human cognition, and reward processing specifically, via increased dopamine D1-receptor signalling. However, the effect of estradiol on reward processing in men has never been established. To fill this gap, we performed a double-blind placebo-controlled study in which men (N = 100) received either a single dose of estradiol (2 mg) or a placebo. Subjects performed a probabilistic reinforcement learning task where they had to choose between two options with varying reward probabilities to maximize monetary reward. Results showed that estradiol administration increased reward sensitivity compared to placebo. This effect was observed in subjects' choices, how much weight they assigned to their previous choices, and subjective reports about the reward probabilities. Furthermore, effects of estradiol were moderated by reward sensitivity, as measured through the BIS/BAS questionnaire. Using reinforcement learning models, we found that behavioral effects of estradiol were reflected in increased learning rates. These results demonstrate a causal role of estradiol within the framework of reinforcement learning, by enhancing reward sensitivity and learning. Furthermore, they provide preliminary evidence for dopamine-related genetic variants moderating the effect of estradiol on reward processing.
雌激素被假设在人类认知中发挥关键作用，特别是在奖励处理方面，通过增加多巴胺 D1 受体信号。然而，雌激素对男性奖励处理的影响尚未确定。为了填补这一空白，我们进行了一项双盲安慰剂对照研究，其中 100 名男性（N=100）接受了单剂量的雌激素（2 毫克）或安慰剂。受试者进行了一项概率强化学习任务，他们必须在两个具有不同奖励概率的选项之间进行选择，以最大限度地获得货币奖励。结果表明，与安慰剂相比，雌激素给药增加了奖励敏感性。这种效应在受试者的选择、他们对先前选择的重视程度以及对奖励概率的主观报告中都有体现。此外，雌激素的作用受到 BIS/BAS 问卷测量的奖励敏感性的调节。使用强化学习模型，我们发现雌激素的行为效应反映在学习率的提高上。这些结果在强化学习框架内证明了雌激素的因果作用，通过增强奖励敏感性和学习。此外，它们提供了初步证据，表明多巴胺相关的遗传变异调节了雌激素对奖励处理的影响。
