Introduction:
A number of investigative methods, for example, structural, metabolic and functional, have indicated a role for the auditory cortices in the patho-physiology of schizophrenia. However, few studies have completed multimodal investigations in the same participants. The aim of this study was to explore the structure and function of the auditory cortices in patients with schizophrenia.
Methods:
Structural and functional magnetic resonance imaging (fMRI)images were acquired for 27 patients with schizophrenia and 16 normal controls. Heschl's gyrus (HG) and planum temporale (PT) were manually delineated on the structural scans of all subjects in both hemispheres. A structural laterality coefficient was calculated based on region of interest (ROI) volumes. The fMRI data were recorded while the subjects passively listened to semantically neutral words. The functional data were then coregistered with the structural images, and a functional laterality coefficient was calculated based on the number of activated voxels in the ROIs. The structural and functional laterality coefficients were compared across the groups using ANOVA.
Results:
For HG, patients showed significantly reduced structural leftward laterality and increased functional rightward laterality in contrast to the control group. For PT, we found no structural differences between the groups, all groups were symmetric, while functionally again we found increased rightward laterality for the patients when compared with controls.
Conclusions:
Patients with schizophrenia showed both reduced volume and poor activation of their left hemisphere auditory cortices. It therefore appears to be the case that language functions normally processed in the left hemisphere are processed in the right hemisphere in these individuals.
