Multisensory Integration and Pragmatic Processing in Schizophrenia: Evidence from the Rubber Hand Illusion

Pragmatic impairments are a core feature of schizophrenia, yet their underlying mechanisms remain only partially understood. Beyond deficits in cognition and social cognition, recent accounts suggest that alterations in multisensory integration and embodiment may contribute to communicative dysfunction. In the present study, we tested the hypothesis that disturbances in multisensory integration are associated with pragmatic deficits in schizophrenia.Across two studies, individuals with schizophrenia spectrum disorders underwent a Rubber Hand Illusion (RHI) paradigm to assess multisensory integration and bodily self-representation. In Study 1, pragmatic abilities were evaluated using APACS, a comprehensive battery assessing both expressive and receptive pragmatics. In Study 2, metaphor comprehension was specifically examined via the PMM task. Illusory experience was indexed through subjective measures (embodiment, disembodiment) and an objective index (proprioceptive drift).Results showed that patients exhibited a dysfunctional illusion experience. While subjective measures were not related to pragmatics, greater proprioceptive drift was consistently associated with poorer pragmatic abilities, in both production and comprehension, even when controlling for cognitive performance and symptom severity. In the metaphor task, both subjective and objective illusion susceptibility predicted difficulty with the mental dimension of metaphors.These findings suggest that low-level multisensory integration contributes to higher-order pragmatic abilities. We propose that an imbalance between sensory-based and integrative mechanisms may underlie both altered bodily self-representation and communicative impairments in schizophrenia, supporting accounts of a “disembodied self” coupled with a “hyper-symbolic” use of language.