McGuire P K, Paulesu E, Frackowiak R S, Frith C D
Department of Psychological Medicine, Institute of Psychiatry, London, UK.
Neuroreport. 1996 Sep 2;7(13):2095-9.
The neural correlates of stimulus-independent thoughts (SITs) were investigated in two studies of normal volunteers, using positron emission tomography (PET) and H2(15)O to measure regional cerebral blood flow. Subjects rated how frequently SITs occurred while they were concurrently performing different sets of cognitive tasks. In both studies, the main positive correlations between SITs and blood flow were in the medial prefrontal region. These correlations were not attributable to between-task differences in cognitive demand, or to effects of practice on these demands. An association between medial prefrontal activity and SITs is consistent with data linking this region to self-initiated thought, and its activation during tasks which entail thinking which is decoupled from stimuli in the immediate environment.
在两项针对正常志愿者的研究中，使用正电子发射断层扫描（PET）和H2(15)O来测量局部脑血流量，对与刺激无关的思维（SITs）的神经关联进行了研究。受试者在同时执行不同组认知任务时，对SITs出现的频率进行评分。在两项研究中，SITs与血流量之间的主要正相关均出现在内侧前额叶区域。这些相关性并非归因于认知需求的任务间差异，也不是练习对这些需求的影响。内侧前额叶活动与SITs之间的关联，与将该区域与自发思维联系起来的数据一致，并且在需要与即时环境中的刺激脱钩的思维任务中，该区域会被激活。
