Impaired self-awareness has been noted as a core feature of schizophrenia. Recent neuroimaging studies examining self-referential process in schizophrenia have yielded inconsistent results. We aimed to examine the self-referential neural network using the self- and other-evaluation tasks in schizophrenia.

Fifteen schizophrenia patients and fifteen age-, sex- and parental education-matched healthy subjects underwent functional magnetic resonance imaging. Subjects were required to make a decision whether the sentence described their own personal trait (self-evaluation) and that of their close friends (other-evaluation).

Both patients and healthy groups showed significant activation in multiple brain regions including the medial- and lateral-prefrontal, temporal and parietal cortices during self- and other-evaluation tasks. The control subjects showed higher activations in left posterior cingulate and parahippocampal gyri during self-evaluation than other-evaluation, whereas there was no difference in activated regions between self- and other-conditions in the patients. As compared with the controls, the patients showed higher activations in the right superior frontal and right supramarginal gyri during self-evaluation.

These findings provide evidence for neural basis for deficits in self-awareness in schizophrenia and may underlie core clinical symptomatology of schizophrenia.