Differences in audiovisual integration, as measured by McGurk phenomenon, among adult and adolescent patients with schizophrenia and age-matched healthy control groups.

BACKGROUND: McGurk effect is a perceptual phenomenon that reflects the integration of visual and auditory information during speech perception. Using McGurk effect, the authors examined the audiovisual integration in adolescents and adults with schizophrenia as compared with healthy volunteers. SAMPLING AND METHODS: Thirty hospitalized patients with schizophrenia and 20 age-matched healthy controls were examined for perception of ambiguous audiovisual stimuli.
RESULTS: The mean of McGurk-positive responses was significantly lower in adolescent patients with schizophrenia than in healthy adolescents (3.13 +/- 2.09 vs 5.60 +/- 0.7, respectively; t = 3.591, P = .001). The McGurk-positive responses were significantly higher in healthy adolescents than in healthy adults (5.60 +/- 0.7 vs 3.60 +/- 1.43, respectively; t = 3.974, P = .001). No significant difference in McGurk-positive responses was found between adults with schizophrenia and healthy adult individuals, or between adolescent and adults with schizophrenia. Duration of schizophrenia, soft sign status, type of symptoms, and type of antipsychotic medication showed no influence on the audiovisual integration ability.
CONCLUSIONS: (I) Age effect: It seems that the audiovisual integrative function increases from childhood to adolescence and decreases from adolescence to early adulthood. (II) Schizophrenia: Audiovisual integration is poor in adolescent and adult patients with schizophrenia. Thus, it seems that schizophrenia is associated with early and persistent impairment in the development of the audiovisual integration ability. (III) Reliance on visual cue stimuli: Although several previous investigations concluded that patients with schizophrenia rely less on visual cue stimuli than healthy controls, our data suggest that this is true only for specific types of visual cue stimuli.