NeuroimageNord, Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany.
J Neurosci. 2012 May 16;32(20):6937-46. doi: 10.1523/JNEUROSCI.3553-11.2012.
Sleep deprivation (SD) has detrimental effects on cognition, but the affected psychological processes and underlying neural mechanisms are still essentially unclear. Here we combined functional magnetic resonance imaging and computational modeling to examine how SD alters neural representation of specific choice variables (subjective value and decision conflict) during reward-related decision making. Twenty-two human subjects underwent two functional neuroimaging sessions in counterbalanced order, once during rested wakefulness and once after 24 h of SD. Behaviorally, SD attenuated conflict-dependent slowing of response times, which was reflected in an attenuated conflict-induced decrease in drift rates in the drift diffusion model. Furthermore, SD increased overall choice stochasticity during risky choice. Model-based functional neuroimaging revealed attenuated parametric subjective value signals in the midbrain, parietal cortex, and ventromedial prefrontal cortex after SD. Conflict-related midbrain signals showed a similar downregulation. Findings are discussed with respect to changes in dopaminergic signaling associated with the sleep-deprived state.
睡眠剥夺（SD）对认知有不利影响，但受影响的心理过程和潜在的神经机制在本质上仍不清楚。在这里，我们结合功能磁共振成像和计算建模来研究睡眠剥夺如何改变奖励相关决策过程中特定选择变量（主观价值和决策冲突）的神经表示。22 名人类受试者以平衡的方式进行了两次功能神经影像学检查，一次在清醒休息时，一次在 24 小时睡眠剥夺后。行为上，SD 减弱了反应时的冲突相关减速，这反映在漂移扩散模型中，SD 减弱了冲突引起的漂移率降低。此外，SD 在风险选择期间增加了整体选择随机性。基于模型的功能神经影像学显示，睡眠剥夺后中脑、顶叶皮层和腹内侧前额叶皮层的参数主观价值信号减弱。与冲突相关的中脑信号也出现类似的下调。研究结果与与睡眠剥夺状态相关的多巴胺能信号变化有关。
