Self and other body perception in anorexia nervosa: The role of posterior DMN nodes

Objectives: Body image distortion is a core symptom of anorexia nervosa (AN), which involves alterations in self- (and other’s) evaluative processes arising during body perception. At a neural level, self-related information is thought to rely on areas of the so-called default mode network (DMN), which, additionally, shows prominent synchronised activity at rest. Methods: Twenty female patients with AN and 20 matched healthy controls were scanned using magnetic resonance imaging when: (a) viewing video clips of their own body and another's body; (b) at rest. Between-group differences within the DMN during task performance were evaluated and further explored for task-related and resting-state-related functional connectivity alterations. Results: AN patients showed a hyperactivation of the dorsal posterior cingulate cortex during their own-body processing but a response failure to another’s body processing at the precuneus and ventral PCC. Increased task-related connectivity was found between dPCC–dorsal anterior cingulate cortex and precuneus–mid-temporal cortex. Further, AN patients showed decreased resting-state connectivity between the dPCC and the angular gyrus. Conclusions: The PCC and the precuneus are suggested as key components of a network supporting self–other-evaluative processes implicated in body distortion, while the existence of DMN alterations at rest might reflect a sustained, task-independent breakdown within this network in AN.

目标：体像扭曲是神经性厌食症（AN）的核心症状，该症状涉及在身体感知过程中出现的自我（及其他人的）评价过程的改变。在神经层面上，自我相关信息的处理被认为依赖于所谓的默认模式网络（DMN）区域，此外，DMN在休息状态下表现出显著的同步活动。方法：对20名患有神经性厌食症的女性患者和20名匹配的健康对照者进行磁共振成像扫描，分别处于以下状态：（a）观看自身及他人身体视频片段；（b）休息状态。评估并进一步探索两组受试者在任务执行期间DMN内的组间差异，以及与任务相关和休息状态相关的功能连接改变。结果：在处理自身身体时，神经性厌食症患者表现出背侧后扣带回皮层的过度激活，但在处理他人身体时，位于顶叶和腹侧PCC区域的反应失败。在dPCC-背侧前扣带回皮层和顶叶-中颞叶皮层之间发现了增加的任务相关连接。此外，神经性厌食症患者在休息状态下dPCC与角回之间的连接减少。结论：PCC和顶叶被认为是一个网络的关键组成部分，该网络支持涉及体像扭曲的自我-他人评价过程，而休息状态下DMN的改变可能反映了神经性厌食症中该网络持续的、独立于任务的分解。