Neurobehavioral characteristics and symptomatic correlations of audiovisual multisensory integration in schizophrenia: A systematic review and meta-analysis.

Background: Multisensory integration (MSI) avoids cognitive overload, and the traditional all-or-nothing perspective for dysfunctional MSI in schizophrenia has been increasingly challenged. This study aimed to systematically review and meta-analyze extant evidence on audiovisual MSI in schizophrenia.

Methods: We searched Web of Science, PubMed, PsycINFO and PsycARTICLES databases from inception until April 16th, 2024. Studies using appropriate audiovisual integration tasks to compare either behavioral or neural responses between schizophrenia individuals and healthy controls were included. Primary outcome measures included between-group differences (Hedge's g) and symptomatic correlations (Fisher's z) in three components of audiovisual integration tasks, including audiovisual processing, adaptation and integration. The multilevel random-effects models were used to address statistical dependency.

Results: In total, 209 between-group and 116 correlational effect sizes were synthesized from 46 studies, representing 1108 non-overlapped schizophrenia participants and 1084 healthy controls. The overall dysfunctional audiovisual MSI in schizophrenia (g = -0.50, [95 % CI, -0.64 to -0.37]) was primarily ascribed to the impaired audiovisual processing (g = -0.53, [95 % CI, -0.71 to -0.35]) and adaptation (g = -0.71, [95 % CI, -0.99 to -0.42]), rather than integration itself (g = -0.23, [95 % CI, -0.56 to 0.11]). Pooled correlational effect size was extremely small (z = 0.16, [95 % CI, 0.03 to 0.30]).

Conclusions: Individuals with schizophrenia show dysfunctional multisensory processing and adaptation, but preserve a less impaired multisensory integration ability. Our findings provide implications for clinical interventions, as the relatively preserved audiovisual integration ability may serve as a possible avenue for cognitive training programs.