Reduced activation of superior temporal gyrus during auditory comprehension in young offspring of patients with schizophrenia

Abstract

Background: Smaller Superior Temporal Gyrus (STG) and reduced activation with language tasks have been found in schizophrenia emphasizing the involvement of parts of language network. Recently, we reported smaller STG in individuals at risk for psychosis. In this study, we examined the brain activation for auditory comprehension using fMRI in a group of young offspring of schizophrenia patients (HR) with a hypothesis that HR subjects will not activate STG as well as comparison subjects.

Methods: Fifteen HR (7M, 8F, mean age 15.9±3.1) and 17 comparison subjects (9M and 8F, mean age 14.5±3.5) participated. BOLD fMRI images were obtained using a 4 Tesla scanner with a multi echo-planar imaging sequence. The participants were asked to listen to 30 sec blocks of a story alternated with blocks of the same reading played backwards. The data were analyzed using Statistical Parametric Mapping (SPM5) and a BOLD activation exceeding a threshold of T>2.58 (p<0.01, uncorrected) was considered significant.

Results: The HR showed significantly lower BOLD activation at the STG bilaterally compared to normal controls (left STG; x=-64, y=-48, z=12, Z=2.95, right STG; x=62, y=-50, z=-16, Z=2.77). The effect was more pronounced in males and on left STG.

Conclusions: These data suggest that adolescents at risk for schizophrenia show reduced activation of the STG compared to control subjects during a language related task (listening). This finding adds support to the idea that abnormal development of the language related cortex is a marker of increased susceptibility to schizophrenia and that such deviant development may be mediated by familial/genetic factors.