Auditory MMN is associated with the volume of thalamic higher order nuclei in individuals with psychotic disorders and healthy controls

Objective: Predictive coding is a theoretical framework that integrates models of brain dysconnectivity and psychopathology in psychosis. Thalamocortical dysconnectivity as well as reduced thalamic volumes have been reported in psychotic disorders. However, the role of the thalamus in predictive coding is not clear. We examined the relationship between magnetic resonance imaging (MRI)- based thalamic nuclei volumes and mismatch negativity (MMN), a purported index of prediction error signaling known to be impaired in psychosis. Methods: We obtained MRI and MMN using a roving paradigm from individuals with SCZ spectrum disorder (SSD, n = 60) or bipolar disorder (BD, n = 69) and HC (n = 252). We segmented volumes of 25 thalamic nuclei bilaterally and tested their associations with MMN amplitude using linear models while covarying for age, sex, diagnosis, and intracranial volumes (ICV). Results: We did not find group differences in thalamic volumes that could account for differences in MMN, neither did we find significant volume x diagnosis interactions on MMN for any of the 25 nuclei examined. Across the whole sample, significant positive associations were found between MMN amplitude and the volumes of several higher-order thalamic nuclei, including the mediodorsal medial and lateral nuclei, anterior and medial pulvinar, nucleus reuniens, as well as the lateral geniculate nucleus. Conclusion: The results demonstrate a positive association between MMN amplitude and volumes of thalamic association nuclei in patients with psychotic disorders and HC. These findings may suggest a modulatory role of the thalamus in prediction error signaling.