Schedule of Events | Symposia

Enhanced responses to non-interpretable speech-like stimuli in speech and language brain areas of psychosis patients with auditory hallucinations

Poster Session E - Monday, March 31, 2025, 2:30 – 4:30 pm EDT, Back Bay Ballroom/Republic Ballroom

Tamar Regev¹ (tamaregev@gmail.com), Melissa Hwang², Hee So Kim¹, Evelina Fedorenko¹, Ann Shinn^2,3; ¹MIT, ²McLean Hospital, ³Harvard Medical School

The neural basis of auditory hallucinations (AH) in schizophrenia and related disorders remains debated. We recorded fMRI responses to auditory stimuli in individuals with schizophrenia or psychotic bipolar disorder with (n=42) vs. without (n=37) a lifetime history of AH, alongside healthy control participants (n=35). Auditory stimuli were presented in three conditions in a block design: (1) real sentences, (2) nonword sentences matched for phonological properties, and (3) non-speech auditory stimuli matched to speech acoustics (’speech textures’). In each participant, we identified primary auditory areas anatomically, as well as speech and language areas using validated functional localizers. Results revealed: (i) robust responses across all groups to all conditions in the primary auditory areas, (ii) robust responses across all groups to real sentences in speech and language areas, but critically, (iii) enhanced responses to nonword sentences and speech textures in the speech and language areas in patients with AH, as well as in individuals diagnosed with schizophrenia more generally, relative to controls. These results suggest that in patients with AH, non-interpretable speech-like stimuli propagate further along the auditory pathway, eliciting greater activation in areas downstream of the primary auditory cortex, compared to patients without AH or controls. While this study examined responses to external auditory stimuli, it is plausible that, in the absence of external input, a similar process is endogenously generated, leading to salient verbal percepts; this feature of the auditory-speech-language pathway deserves further investigation as a possible mechanism underlying auditory hallucinations.

Topic Area: LANGUAGE: Other