Bertossi Elena, Ciaramelli Elisa
Dipartimento di Psicologia.
Centro Studi e Ricerche in Neuroscienze Cognitive, Università di Bologna, Italy.
Soc Cogn Affect Neurosci. 2016 Nov;11(11):1783-1791. doi: 10.1093/scan/nsw099. Epub 2016 Jul 21.
Mind-wandering, an ubiquitous expression of humans' mental life, reflects a drift of attention away from the current task towards self-generated thoughts, and has been associated with activity in the brain default network. To date, however, little is understood about the contribution of individual nodes of this network to mind-wandering. Here, we investigated whether the ventromedial prefrontal cortex (vmPFC) is critically involved in mind-wandering, by studying the propensity to mind-wander in patients with lesion to the vmPFC (vmPFC patients), control patients with lesions not involving the vmPFC, and healthy individuals. Participants performed three tasks varying in cognitive demands while their thoughts were periodically sampled, and a self-report scale of daydreaming in daily life. vmPFC patients exhibited reduced mind-wandering rates across tasks, and claimed less frequent daydreaming, than both healthy and brain-damaged controls. vmPFC damage reduced off-task thoughts related to the future, while it promoted those about the present. These results indicate that vmPFC critically supports mind-wandering, possibly by helping to construct future-related scenarios and thoughts that have the potential to draw attention inward, away from the ongoing tasks.
思绪游走是人类精神生活中普遍存在的一种表现，反映了注意力从当前任务转向自我产生的想法，并且与大脑默认网络的活动有关。然而，迄今为止，对于该网络中各个节点对思绪游走的贡献了解甚少。在此，我们通过研究腹内侧前额叶皮质（vmPFC）受损患者（vmPFC患者）、不涉及vmPFC的病变对照患者以及健康个体的思绪游走倾向，来探究vmPFC是否在思绪游走中起关键作用。参与者在其思维被定期采样时执行了三项认知需求不同的任务，以及一项关于日常生活中白日梦的自我报告量表。与健康和脑损伤对照相比，vmPFC患者在各项任务中的思绪游走率均降低，且声称白日梦频率较低。vmPFC损伤减少了与未来相关的非任务思维，同时增加了与当下相关的非任务思维。这些结果表明vmPFC可能通过帮助构建与未来相关的情景和想法，从而潜在地将注意力吸引到内部、远离正在进行的任务，进而对思绪游走起到关键支持作用。
