Reduced language-related cortex activity linked to schizophrenia susceptibility
MedWire News: Adolescents at risk of schizophrenia have reduced activity in the superior temporal gyrus (STG) during a listening task, US scientists have discovered in findings that support the hypothesis of poor language-related cortex development in schizophrenia.
Schizophrenia patients have been found to have a smaller STG and reduced activation during language tasks compared with healthy individuals, and a recent study indicated that individuals at risk of psychosis have a smaller STG.
To investigate further, Rajaprabhakaran Rajarethinam, from Wayne State University in Detroit, Michigan, and colleagues used functional magnetic resonance imaging (fMRI) to obtain blood oxygen level dependent (BOLD) images of 15 high-risk (HR) children of schizophrenia patients and 17 healthy matched controls.
The participants were administered a task in which they were asked to listen to 30 second sections of a story alternated with sections of the same story played backwards. BOLD activation greater than a T of 2.58 on Statistical Parametric Mapping was considered significant.
When the two participant groups were analyzed separately, both showed significant activation of the STG during the task. However, the HR group showed significantly lower BOLD activation at the STG bilaterally compared with healthy controls.
Further analysis revealed that the difference in activation between HR individuals and controls was more pronounced in males and in the left STG. However, the sample size was too small to be able to draw conclusions.
"These fMRI findings add support to the notion that abnormal development of the language-related cortex may be a marker of increased susceptibility to schizophrenia and that such deviant development may be mediated by familial/genetic factors," the team says in the journal Schizophrenia Research.
They add: "Focused investigation and follow-up of [at risk] individuals may help clarify neurofunctional language-related susceptibility markers and predictors of future psychosis."
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By Liam Davenport