Temporally unpredictable stimuli influence behavior across species, as previously demonstrated for sequences of simple threats and rewards with fixed or variable onset. Neuroimaging studies have identified a specific frontolimbic circuit that may become engaged during the anticipation of temporally unpredictable threat (U-threat). However, the neural mechanisms underlying processing of temporally unpredictable reward (U-reward) are incompletely understood. It is also unclear whether these processes are mediated by overlapping or distinct neural systems. These knowledge gaps are noteworthy given that disruptions within these neural systems may lead to maladaptive response to uncertainty. Here, using functional magnetic resonance imaging data from a sample of 159 young adults, we showed that anticipation of both U-threat and U-reward elicited activation in the right anterior insula, right ventral anterior nucleus of the thalamus and right inferior frontal gyrus. U-threat also activated the right posterior insula and dorsal anterior cingulate cortex, relative to U-reward. In contrast, U-reward elicited activation in the right fusiform and left middle occipital gyrus, relative to U-threat. Although there is some overlap in the neural circuitry underlying anticipation of U-threat and U-reward, these processes appear to be largely mediated by distinct circuits. Future studies are needed to corroborate and extend these preliminary findings.

中文翻译：

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共享和独特的神经回路是时间不可预测的威胁和奖励处理的基础

时间上不可预测的刺激会影响跨物种的行为，如先前针对具有固定或可变起始的简单威胁和奖励序列所证明的那样。神经影像学研究已经确定了一个特定的前肢回路，该回路可能会在预期时间不可预测的威胁（U-威胁）期间参与。然而，对时间不可预测奖励（U-reward）处理的神经机制尚不完全清楚。目前还不清楚这些过程是由重叠的还是不同的神经系统介导的。鉴于这些神经系统内的中断可能导致对不确定性的适应不良反应，这些知识差距值得注意。在这里，使用来自 159 名年轻人样本的功能性磁共振成像数据，我们发现，对 U 威胁和 U 奖励的预期会引发右前岛叶、丘脑右腹前核和右额下回的激活。相对于 U 奖励，U 威胁还激活了右后岛叶和背侧前扣带皮层。相比之下，相对于 U 威胁，U 奖励引起右侧梭状回和左侧枕中回的激活。尽管预测 U 威胁和 U 奖励的神经回路存在一些重叠，但这些过程似乎主要由不同的回路介导。需要进一步的研究来证实和扩展这些初步发现。相对于 U 奖励，U 威胁还激活了右后岛叶和背侧前扣带皮层。相比之下，相对于 U 威胁，U 奖励引起右侧梭状回和左侧枕中回的激活。尽管预测 U 威胁和 U 奖励的神经回路存在一些重叠，但这些过程似乎主要由不同的回路介导。需要进一步的研究来证实和扩展这些初步发现。相对于 U 奖励，U 威胁还激活了右后岛叶和背侧前扣带皮层。相比之下，相对于 U 威胁，U 奖励引起右侧梭状回和左侧枕中回的激活。尽管预测 U 威胁和 U 奖励的神经回路存在一些重叠，但这些过程似乎主要由不同的回路介导。需要进一步的研究来证实和扩展这些初步发现。