Neural responses during social reflection in relatives of schizophrenia patients: relationship to subclinical delusions

BACKGROUND: Deficits in the capacity to reflect about the self and others ("social reflection" [SR]) have been identified in schizophrenia, as well as in people with a genetic or clinical risk for the disorder. However, the neural underpinnings of these abnormalities are incompletely understood.
METHODS: Responses of a network of brain regions known to be involved in self and other processing (e.g., medial prefrontal cortex (MPFC), posterior cingulate cortex (PCC), and superior temporal gyrus (STG)) were measured during SR in 16 first-degree, non-psychotic relatives (RELS) of schizophrenia patients and 16 healthy controls (CONS). Because of prior evidence linking dysfunction in this network and delusions, associations between SR-related responses of this network and subclinical delusions (measured using the Peters et al. Delusions Inventory) were also examined.
RESULTS: Compared with CONS, RELS showed significantly less SR-related activity of the right and left PCC and STG. Moreover, response magnitudes were negatively correlated with levels of delusional thinking across both groups.
CONCLUSIONS: These findings suggest that aberrant function of the neural circuitry underpinning SR is associated with the genetic liability to schizophrenia and confers vulnerability to delusional beliefs.