Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, the Netherlands.
Hum Brain Mapp. 2010 Aug;31(8):1117-27. doi: 10.1002/hbm.20920.
Activity within the default-mode network (DMN) is thought to be related to self-referential processing, such as thinking about one's preferences or personality traits. Although the DMN is generally considered to function as a network, evidence is starting to accumulate that suggests that areas of the DMN are each specialized for different subfunctions of self-referential processing. Here, we address the issue of functional specialization by investigating changes in coupling between areas of the DMN during self-referential processing. To this aim, brain activity was assessed during a task in which subjects had to indicate whether a trait adjective described their own personality (self-referential, Self condition), that of another person (other-referential, Other condition), or whether the trait was socially desirable (nonreferential, Control condition). To exclude confounding effects of cardiorespiratory processes on activity and functional coupling, we corrected the fMRI signal for these effects. Activity within areas of the DMN was found to be modulated by self-referential processing. More specifically, during the Self condition compared to the Other and Control condition, activity within the dorsal medial prefrontal cortex, ventral medial prefrontal cortex, and posterior cingulate cortex was increased. Moreover, coupling between areas of the DMN was reduced during the Self condition compared to the Other and Control condition, while coupling between regions of the DMN and regions outside the network was increased. As such, these results provide an indication for functional specialization within the DMN and support the notion that each area of the DMN is involved in different subfunctions of self-referential processing.
默认模式网络（DMN）中的活动被认为与自我参照处理有关，例如思考自己的偏好或个性特征。尽管 DMN 通常被认为是一个网络，但越来越多的证据表明，DMN 的各个区域都专门用于自我参照处理的不同子功能。在这里，我们通过研究自我参照处理过程中 DMN 区域之间的耦合变化来解决功能专业化的问题。为此，我们在一项任务中评估了大脑活动，在该任务中，受试者必须判断一个特质形容词是否描述了自己的个性（自我参照，Self 条件）、他人的个性（他人参照，Other 条件）或该特质是否具有社会吸引力（非参照，Control 条件）。为了排除心肺过程对活动和功能耦合的混杂影响，我们对 fMRI 信号进行了这些影响的校正。DMN 内的活动被发现受到自我参照处理的调节。更具体地说，与 Other 和 Control 条件相比，在 Self 条件下，背内侧前额叶皮质、腹内侧前额叶皮质和后扣带回皮质内的活动增加。此外，与 Other 和 Control 条件相比，Self 条件下 DMN 区域之间的耦合减少，而 DMN 区域与网络外区域之间的耦合增加。因此，这些结果表明 DMN 内存在功能专业化，并支持每个 DMN 区域都参与自我参照处理的不同子功能的观点。
