THE ROLE OF LANGUAGE PROCESSING BRAIN REGIONS IN AUDITORY HALLUCINATIONS IN SCHIZOPHRENIA: A SYMPTOM CAPTURE FMRI STUDY

Auditory verbal hallucinations (AVH) are a core symptom of schizophrenia, affecting approximately 70% of patients. Recent research has emphasized the involvement of language-related brain regions, particularly Broca’s area, in their generation. The present study investigated brain activation patterns associated with AVH using the ‘symptom capture’ fMRI paradigm where patients with frequent AVH press a button each time they experience them. We also incorporated two novel conditions involving hearing real auditory stimuli with and without a button press. Fifteen patients with a DSM-5 diagnosis of schizophrenia and near-continuous AVH underwent 3T fMRI during blocks of (i) AVH symptom capture, (ii) hearing real speech similar to their AVH (without a button press), and (iii) hearing a brief instruction to button press. Data were preprocessed and analyzed with the Feat module in FSL software with p<0.05 FWE-corrected at the cluster level. Experience of AVH was associated with significant activation in the inferior frontal cortex, supramarginal gyrus (overlapping with Broca’s and Wernicke’s areas), and the supplementary motor area (SMA), but there was no activation of the auditory cortex. In contrast, hearing AVH-like real speech strongly activated the auditory cortex as well as Broca’s and Wernicke’s areas. The motor response condition activated the auditory and motor cortices, but unexpectedly did not activate the SMA. These results replicate and extend our previous study using a different symptom capture paradigm and highlight the role of Broca’s area, other language processing brain regions, and the SMA in brain processes underlying AVH.