Multisensory processes can compensate for attention deficits in schizophrenia

Previous conflicting findings on multisensory integration in schizophrenia might be related to differences in top-down attention demands across the different studies. We tested this with a visuo-tactile stimulation paradigm and high-density event-related potentials (ERPs) to examine the interplay between multisensory integration and top-down intersensory attention in healthy controls (N=27) and in people with schizophrenia (N=27). Unisensory visual, unisensory tactile or bisensory stimuli while participants attended to either visual or tactile inputs. D-prime values, ERPs, clinical symptomatology, and cognitive performance were examined, comparing the interplay of intersensory attention and multisensory integration between groups. The former was impaired in the schizophrenia group at the behavioral level, but only for unisensory and not for multisensory stimuli. ERPs showed earlier intersensory attention responses ( 230ms) over frontal and occipital brain areas. In contrast, multiple phases of multisensory integration, starting around 240ms, were preserved in the schizophrenia group. There was no correlation between ERP response and positive or negative symptoms. Our study provides evidence for long latency intersensory attention deficits in schizophrenia, presumably reflecting aberrant top-down processing. These findings indicate that uncompromised integrative multisensory processes, which elevate and capture attention, may serve as a compensatory mechanism for aberrant top-down processing in schizophrenia. Differences in attentional demands may have contributed to previous conflicting findings.