Department of Psychiatry, University of Michigan, Rachel Upjohn Building, Ann Arbor, MI, 48109, USA.
Department of Psychology, Pennsylvania State University, Moore Building, State College, PA, USA.
Brain Imaging Behav. 2021 Oct;15(5):2254-2268. doi: 10.1007/s11682-020-00419-y. Epub 2021 Jan 6.
Human cognitive performance is often disrupted by distractions related to aversive stimuli and affective states, but, paradoxically, there is also evidence to suggest that high working memory demands reduce the impact of aversive distraction. Previous empirical work suggests this latter effect occurs because working memory demands reduce attention to off-task processes, but the brain regions that mediate this effect remain uncertain. The current study utilizes a novel distraction manipulation involving unpleasant odorants to identify neural structures that buffer performance from aversive distraction under high working memory demands, and to clarify their connectivity in this context. Twenty-one healthy young adults (12 women) completed a verbal n-back task under two levels of load and were concurrently exposed to either room air or aversive odorants. Three brain regions displayed increases in neural responses to olfactory distractors under high load only; the left dorsolateral prefrontal cortex, the left ventrolateral prefrontal cortex and right cerebellar Crus I. Of these regions, only the ventrolateral prefrontal cortex also displayed context-specific connectivity with a region thought to be involved in off-task processes: the dorsomedial prefrontal cortex. Overall, results suggest that, under high working memory demands, areas of the prefrontal cortex and cerebellum shield cognition from aversive distraction, potentially through interactions with brain structures involved in off-task processes.
人类的认知表现常常会受到与厌恶刺激和情绪状态相关的干扰而受到影响，但矛盾的是，也有证据表明，高工作记忆需求会降低厌恶干扰的影响。先前的实证研究表明，这种后一种效应的发生是因为工作记忆需求减少了对非任务过程的注意力，但介导这种效应的大脑区域仍不确定。本研究利用一种涉及不愉快气味的新颖分心操作，来确定在高工作记忆需求下缓冲厌恶分心对表现影响的神经结构，并阐明它们在这种情况下的连接。21 名健康的年轻成年人（12 名女性）在两种负荷水平下完成了口头 n 回任务，并同时暴露于空气或厌恶气味中。三个大脑区域在高负荷下仅对嗅觉分心者的神经反应增加；左背外侧前额叶皮层、左腹外侧前额叶皮层和右小脑 Crus I。在这些区域中，只有腹外侧前额叶皮层还显示出与被认为涉及非任务过程的区域的特定于上下文的连接：背内侧前额叶皮层。总体而言，结果表明，在高工作记忆需求下，前额叶皮层和小脑的区域可以保护认知免受厌恶分心的影响，这可能是通过与涉及非任务过程的大脑结构相互作用来实现的。
