The self and its resting state in consciousness: An investigation of the vegetative state

Recent studies have demonstrated resting-state abnormalities in midline regions in vegetative state=unresponsive wakefulness syndrome and minimally conscious state patients. However, the func- tional implications of these resting-state abnormalities remain unclear. Recent findings in healthy sub- jects have revealed a close overlap between the neural substrate of self-referential processing and the resting-state activity in cortical midline regions. As such, we investigated task-related neural activity during active self-referential processing and various measures of resting-state activity in 11 patients with disorders of consciousness (DOC) and 12 healthy control subjects. Overall, the results revealed that DOC patients exhibited task-specific signal changes in anterior and posterior midline regions, including the perigenual anterior cingulate cortex (PACC) and posterior cingulate cortex (PCC). How- ever, the degree of signal change was significantly lower in DOC patients compared with that in healthy subjects. Moreover, reduced signal differentiation in the PACC predicted the degree of con- sciousness in DOC patients. Importantly, the same midline regions (PACC and PCC) in DOC patients