Response time as a proxy of ongoing mental state: A combined fMRI and pupillometry study in Generalized Anxiety Disorder
Response time as a proxy of ongoing mental state: A combined fMRI and pupillometry study in Generalized Anxiety Disorder
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DOI：
10.1016/j.neuroimage.2019.02.038
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发表时间：
2019-05
期刊：
影响因子：
5.7
通讯作者：
Elena Makovac;S. Fagioli;D. Watson;F. Meeten;J. Smallwood;H. Critchley;C. Ottaviani
中科院分区：
文献类型：
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作者：
Elena Makovac;S. Fagioli;D. Watson;F. Meeten;J. Smallwood;H. Critchley;C. Ottaviani
在广泛性焦虑症（GAD）中，正在进行的想法的波动（即，走神）通常采取僵化和侵入性的持续认知的形式，例如担心。在这里，我们试图解释走神和持续认知的神经相关性，以及中枢唤醒的自主神经系统指数，特别是瞳孔扩张。我们实现了一个协议，将动态交付的思想探针内的功能性神经成像任务。16名GAD患者和16名匹配的健康对照（HC）进行了功能性磁共振成像，同时进行瞳孔测量。参与者执行了一系列低需求的跟踪任务，对目标刺激的偶尔变化做出反应。这样的任务通常伴随着自我生成的、脱离任务的思维。当个体对目标的变化做出反应时，基于个体的反应时间（RT）触发。主观报告显示，长RT预测任务外思维/走神。此外，长RT和走神也与较大的瞳孔直径。这种效应在GAD患者的持续认知中被夸大了。在大脑内部，在目标前时期和目标事件期间，对于走神有不同的神经相关性（例如，目标开始时的前扣带和旁扣带激活）和持续认知（例如，在HC和GAD中，后扣带回和小脑在靶点发作时的激活模式相反）。结果表明，不仅注意系统，但也感觉运动皮层是重要的，在关闭任务状态。有趣的是，“默认模式网络”的变化也跟踪了瞳孔大小的波动。瞳孔变化中的自主神经表达反映了在不同形式的重复思维中发生的大脑激活模式。
In Generalized Anxiety Disorder (GAD), fluctuations in ongoing thoughts (i.e., mind-wandering) often take the form of rigid and intrusive perseverative cognition, such as worry. Here, we sought to characterise the neural correlates of mind-wandering and perseverative cognition, alongside autonomic nervous system indices of central arousal, notably pupil dilation. We implemented a protocol incorporating the dynamic delivery of thought-probes within a functional neuroimaging task. Sixteen individuals with GAD and sixteen matched healthy controls (HC) underwent functional magnetic resonance imaging with concomitant pupillometry. Participants performed a series of low-demand tracking tasks, responding to occasional changes in a target stimulus. Such a task is typically accompanied by self-generated, off-task thinking. Thought-probes were triggered based on an individual's response time (RT) when responding to the change in the target. Subjective reports showed that long RT predicted off-task thinking/mind-wandering. Moreover, long RT and mind-wandering were also associated with larger pupil diameter. This effect was exaggerated in GAD patients during perseverative cognition. Within brain, during both pre-target periods and target events, there were distinct neural correlates for mind-wandering (e.g., anterior cingulate and paracingulate activation at target onset) and perseverative cognition (e.g., opposite patterns of activation in posterior cingulate and cerebellum at target onset in HC and GAD). Results suggest that not only attention systems but also sensory-motor cortices are important during off-task states. Interestingly, changes across the ‘default mode network’ also tracked fluctuations in pupillary size. Autonomic expression in pupillary changes mirrors brain activation patterns that occur during different forms of repetitive thinking.