Interoceptive dysfunction and its neural correlates in schizophrenia: protocol for a cross-sectional multimodal MRI study

Background: Interoception-the perception and integration of internal bodily signals-is fundamental to emotion regulation, bodily self-awareness, and predictive coding. Emerging evidence suggests that interoceptive disturbances may contribute to core psychopathological features of schizophrenia. Our research group recently conducted a systematic review and meta-analysis demonstrating significant impairments in interoceptive accuracy and sensitivity among individuals with schizophrenia. However, the neural mechanisms underlying these deficits remain unclear. Methods: This cross-sectional protocol will recruit 30 individuals with schizophrenia and 30 age- and sex-matched healthy controls. Participants will complete (1) behavioral interoceptive assessment using the heartbeat counting task; (2) subjective interoceptive questionnaires, including the Multidimensional Assessment of Interoceptive Awareness (MAIA) and the Body Perception Questionnaire (BPQ); (3) clinical symptom ratings (PANSS, HAM-A, HAM-D); and (4) cognitive testing (TMT, animal fluency, DSST). All participants will undergo multimodal MRI scanning, including structural T1-weighted imaging, resting-state fMRI, and diffusion tensor imaging. Neuroimaging data will be preprocessed and analyzed using DPABISurf, SPM12, and GRETNA. Expected Results: We anticipate that individuals with schizophrenia will show reduced interoceptive accuracy, altered subjective interoceptive awareness, and abnormal intrinsic neural activity and connectivity within interoception-related circuits, including the anterior insula, anterior cingulate cortex, amygdala, and thalamus. Structural abnormalities within thalamo-cortical pathways are also expected. Interoceptive deficits are hypothesized to correlate with symptom severity and cognitive performance. Conclusions: This study will provide an integrated characterization of interoceptive dysfunction and its neural correlates in schizophrenia. Findings may advance understanding of bodily self-disturbance and emotional dysregulation and support the development of future interoception-focused therapeutic approaches. Clinical trial registration: https://www.chictr.org.cn/, identifier ChiCTR2500110551.