Sleep and circadian timing shifts later during adolescence, conflicting with early school start times, and resulting in circadian misalignment. Although circadian misalignment has been linked to depression, substance use, and altered reward function, a paucity of experimental studies precludes the determination of causality. Here we tested, for the first time, whether experimentally-imposed circadian misalignment alters the neural response to monetary reward and/or response inhibition.

Healthy adolescents (n = 25, ages 13–17) completed two in-lab sleep schedules in counterbalanced order: An ‘aligned’ condition based on typical summer sleep-wake times (0000–0930) and a ‘misaligned’ condition mimicking earlier school year sleep-wake times (2000–0530). Participants completed morning and afternoon functional magnetic resonance imaging scans during each condition, including monetary reward (morning only) and response inhibition (morning and afternoon) tasks. Total sleep time and circadian phase were assessed via actigraphy and salivary melatonin, respectively.

Bilateral ventral striatal (VS) activation during reward outcome was lower during the Misaligned condition after accounting for the prior night's total sleep time. Bilateral VS activation during reward anticipation was lower during the Misaligned condition, including after accounting for covariates, but did not survive correction for multiple comparisons. Right inferior frontal gyrus activation during response inhibition was lower during the Misaligned condition, before and after accounting for total sleep time and vigilant attention, but only during the morning scan.

Our findings provide novel experimental evidence that circadian misalignment analogous to that resulting from school schedules may have measurable impacts on healthy adolescents' reward processing and inhibition of prepotent responses.

在青春期，睡眠和昼夜节律时间会发生变化，与较早的上学时间相冲突，导致昼夜节律失调。尽管昼夜节律失调与抑郁、药物滥用和奖赏功能改变有关，但由于缺乏实验研究，无法确定因果关系。在这里，我们首次测试了实验施加的昼夜节律失调是否会改变对金钱奖励和/或反应抑制的神经反应。

健康青少年（ n = 25，年龄 13–17）以平衡的顺序完成了两个实验室内睡眠时间表：基于典型夏季睡眠觉醒时间 (0000–0930) 的“对齐”条件和模仿早期学校的“错位”条件年睡眠-觉醒时间 (2000–0530)。参与者在每种情况下完成上午和下午的功能磁共振成像扫描，包括金钱奖励（仅上午）和反应抑制（上午和下午）任务。分别通过体动记录仪和唾液褪黑激素评估总睡眠时间和昼夜节律阶段。

在考虑前一天晚上的总睡眠时间后，在错位条件下，奖励结果期间的双侧腹侧纹状体（VS）激活较低。在错位条件下，奖励预期期间的双边 VS 激活较低，包括在考虑协变量之后，但未经过多重比较的校正。在错位条件下，在考虑总睡眠时间和警惕注意力之前和之后，反应抑制期间的右额下回激活较低，但仅在早晨扫描期间。

我们的研究结果提供了新的实验证据，表明昼夜节律失调（类似于学校时间表造成的昼夜节律失调）可能对健康青少年的奖励处理和优势反应的抑制产生可测量的影响。