During acute energy deprivation, hunger signaling mechanisms support homeostasis by enhancing incentive for food. There is some evidence (primarily based on nonhuman experiments) that fasting heightens incentive signaling for nonfood reward as well. We hypothesized that, consistent with results from research in rodent and nonhuman primates, human participants would evidence increased incentive-related brain activity for nonfood rewards during fast (relative to satiety) and that this increase would be heightened when available rewards were immediate. To assess these possibilities, healthy participants with body mass index between 18 and 29 kg/m2 completed a task which engaged participants in opportunities to win immediate and delayed money (Monetary Incentive Delay Task) during 2 neuroimaging sessions (1 postprandial, 1 fasted). Analyses of participants (N = 18 included, body mass index 22.12± 2.72, age 21.39± 3.52) focused on brain activity during the incentive window of the task. Region of interest, as well as whole-brain analyses, supported the hypothesized increase in incentive signaling during fasting in regions that included caudate and putamen. No evidence of interaction was observed between fasting and the effect of reward immediacy or reward magnitude. Although provisional given the modest sample size, these results suggest that acute fasting can heighten incentive signaling for nonfood rewards.

中文翻译：

---

禁食可能会增加非食物奖励的激励信号

在严重的能量缺乏期间，饥饿信号机制通过增强对食物的激励来支持体内平衡。有一些证据（主要基于非人类实验）表明禁食也会增强非食物奖励的激励信号。我们假设，与啮齿动物和非人类灵长类动物的研究结果一致，人类参与者会证明在禁食期间（相对于饱腹感）非食物奖励会增加与激励相关的大脑活动，并且当可用奖励立即出现时，这种增加会加剧。为了评估这些可能性，体重指数在 18 到 29 kg/m2 之间的健康参与者完成了一项任务，该任务让参与者有机会在 2 次神经成像会议（1 次餐后，1 次禁食）期间赢得即时和延迟金钱（货币激励延迟任务）。参与者（包括 N = 18，体重指数 22.12± 2.72，年龄 21.39± 3.52）的分析侧重于任务激励窗口期间的大脑活动。感兴趣的区域以及全脑分析支持在包括尾状核和壳核的区域禁食期间激励信号的假设增加。没有观察到禁食与奖励即时性或奖励幅度的影响之间存在相互作用的证据。尽管鉴于样本量不大，这些结果是暂时的，但这些结果表明，急性禁食可以增强对非食物奖励的激励信号。支持在包括尾状核和壳核的区域禁食期间激励信号的假设增加。没有观察到禁食与奖励即时性或奖励幅度的影响之间存在相互作用的证据。尽管鉴于样本量不大，这些结果是暂时的，但这些结果表明，急性禁食可以增强对非食物奖励的激励信号。支持在包括尾状核和壳核的区域禁食期间激励信号的假设增加。没有观察到禁食与奖励即时性或奖励幅度的影响之间存在相互作用的证据。尽管鉴于样本量不大，这些结果是暂时的，但这些结果表明，急性禁食可以增强对非食物奖励的激励信号。