Precuneus and psychiatric manifestations: Novel neurobiological formulations through lesion based connectivity mapping of psychopathology

Altered empathy-related resting-state functional connectivity in adolescents with early-onset schizophrenia and autism spectrum disorders

Empathy refers to the ability to understand other people's feelings and reacting emotionally to others. Impaired empathy has been reported in both individuals with schizophrenia and autism spectrum disorders (ASD). Despite overlaps, few studies have directly examined the neural mechanisms of impaired empathy in these two clinical groups. We used resting-state fMRI to investigate the neural correlates of empathic functioning in adolescents with ASD (N = 11), early-onset schizophrenia (EOS) (N = 20), and typically developing (TD) controls (N = 26). Their parents completed the Griffith Empathy Measure (GEM) to assess the adolescents' empathic capacity. We found that EOS and ASD participants both exhibited impaired empathy as measured by the GEM, especially in cognitive empathy (post-hoc ps < 0.05). Regions-of-interest-based functional connectivity revealed decreased connectivity between the salience network (SN) (i.e., the anterior insula and the anterior cingulate cortex) and core regions of the mentalizing network (e.g., the temporal-parietal junction and the precuneus), and among the SN and the bilateral superior temporal gyri (STG) and the left cerebellum in EOS participants. Subsequent comparisons revealed reduced grey matter volume in the STG bilaterally in both clinical groups. Increased resting-state functional connectivity within the social brain network was correlated with higher parent-reported scores of empathic capacity in TD adolescents, but such a brain-phenotype relationship was absent in the two clinical groups. These findings indicate that structural alterations and disturbed resting-state functional connectivity in the core empathy network may be the neural correlates of social cognitive deficits in individuals with EOS and ASD.

Altered neural basis of self-reflective processing in schizophrenia: An fMRI study

BACKGROUND

Impaired self-awareness has often been described in schizophrenia. Recent neuroimaging studies examining the self-reflection processes in schizophrenia have produced inconsistent results.

METHOD

We examined the self-reflective neural network using self- and other-evaluation tasks in schizophrenia. Fifteen schizophrenia patients and fifteen age- and sex-matched healthy subjects underwent functional magnetic resonance imaging. Subjects were required to decide whether the sentence described their own personal trait (self-evaluation) and that of their close friends (other-evaluation).

RESULTS

Unlike normal control subjects, the schizophrenia patients did not have greater activation of the left posterior cingulate gyrus and hippocampus during self-evaluation than during other-evaluation. On the other hand, the schizophrenia patients had higher activation of the right superior frontal and right supramarginal gyri during self-evaluation than control subjects. Only the patient group exhibited hyperactivation in the left hippocampus and right external capsule associated with the other-evaluation task.

CONCLUSIONS

These findings provide evidence for an altered neural basis of self-reflective processing, which may underlie the self-awareness deficits in schizophrenia.