Language lateralization in monozygotic twins discordant for schizophrenia. Evidence from functional MRI
Abstract
Anatomical and functional studies have shown reduced cerebral asymmetry and functional lateralization in schizophrenia. The aim of this study was to assess the relative contribution of nongenetic factors in previously reported decreased language lateralization in schizophrenia using a co-twin control study.
The authors examined the hemispheric dominance for language processing by means of functional MRI in four monozygotic twin pairs discordant for schizophrenia. Subjects were scanned while engaged in verbal fluency task.
All twins were right-handed. The results indicate that language processing is less lateralized in affected twins compared with their well co-twins (a mean laterality index of 0,73 versus 0,90 respectively, difference p < 0,05).
Differences in language lateralization between affected and well co-twins could suggest nongenetic neurodevelopmental reorganization within the network mediating language in twins with schizophrenia