11 - Auditory verbal hallucinations and language lateralization

Summary

This chapter describes cerebral activation during auditory verbal hallucinations (AVH) in a relatively large sample to enable group-wise analysis and obtain a representative view of the biological substrate of hallucinations. Hallucinations are among the most intriguing and characteristic symptoms of schizophrenia. The chapter presents the results of 24 psychotic patients who actually experienced AVH in the scanner. It hypothesizes that the group-wise analysis would reveal activity in language-related structures, such as Broca's and Wernicke's areas, since the percept of these hallucinations consists of words or sentences. Functional magnetic resonance imaging (fMRI) data were analyzed using statistical parametric mapping. Pearson's correlation was used to assess an association between lateralization of AVH and lateralization of language production, and between the lateralization of hallucinatory activity and the degree to which the AVH had a negative emotional content. The group analysis for the language task revealed extensive activation of multiple brain regions.