Deficits in multisensory integration, i.e., simultaneous processing of sensory information from multiple modalities, have recently emerged as characteristic of individuals with schizophrenia and autism spectrum disorders ASD). Although substantial research progress has been made in understanding and treating schizophrenia and ASD, much is still unknown about the neural basis of the deficits in these serious psychiatric disorders. Because higher-order cognitive functions require the brain to integrate information from multiple sources to maintain a coherent perception of external world, the mechanisms by which this integration is achieved may underlie a wide range of normative and pathological processes. Therefore, study focusing on neural substrate of multisensory integration would offer a promising and as yet unexplored approach to understanding the pathophysiology of these psychiatric disorders.
The proposed study will use functional magnetic resonance imaging fMRI) to measure the dynamics of neural circuits integrating visual and tactile information in schizophrenia and high functioning ASD patients as well as in age, sex, and IQ matched healthy controls, while they perform multisensory integration tasks. Two multisensory integration tasks, i.e. visual-tactile motion aftereffect transfer task and rubber hand illusion task, will be used to probe the neural circuits. We aim to quantify abnormal interplay between different brain regions in individuals with psychiatric disorders. Research focusing on neurobiological mechanisms underlying deficits in multisensory integration would allow us to move forward in our understanding of schizophrenia and ASD, reveal target brain region for psychotherapeutic intervention, and use neural signals as biological markers of response to treatment.