Full Program »
171. The relationship between schizotypal personality traits, audiovisual temporal processing, and speech perception
Individuals with schizophrenia have impaired performance at perceiving speech in noisy environments, a deficit which has been related to multisensory integration deficits and altered temporal processing in schizophrenia. This impaired ability to perceive speech in the context of distracting auditory information is thought to be a contributing factor to auditory hallucinations and other abnormal perceptual experiences. Emerging evidence suggests that both individuals with schizotypal personality disorder, and healthy individuals with higher levels of schizotypal personality (SP) traits, are impaired in similar ways to individuals with schizophrenia in cognitive, sensory, and temporal processing. The present study (N = 51) examined whether schizotypal personality traits in the general population are associated with (1) altered multisensory temporal processing, and (2) altered speech perception in noisy environments with distracting auditory information. Temporal processing was assessed with a simultaneity judgment (SJ) task, while SP traits were measured with the schizotypal personality questionnaire (SPQ). Speech perception was measured with a speech-in-noise (SiN) task modified with additional auditory distractor words. These added distractor words were designed to test the hypothesis that auditory hallucinations arise from the mis-binding of auditory and visual speech. Performance on the SJ task was negatively correlated with the Odd Beliefs subscale of the SPQ, r = -.384, p = .005. Several subscales of the SPQ were significantly correlated with several SiN conditions. When the target word and distractor word were separated by 250 ms, the phoneme accuracy of the target word was positively correlated with the Unusual Perceptual Experiences Subscale, r = .355, p = .012. When the target word and distractor word were presented simultaneously, the phoneme accuracy of the target word was negatively correlated with the Suspiciousness Subscale, r = -.290, p = .043. When only the distractor word was presented, in the absence of the target word, the target word accuracy was negatively correlated with the Excessive Social Anxiety Subscale, r = -.290, p = .043. When the target word was presented visually only, without any auditory component, the target word accuracy was negatively correlated with the Suspiciousness Subscale, r = -.293, p = .041. These results suggest that as certain schizotypal personality traits in the general population increase in severity, more precise audiovisual temporal processing is observed. These results align with previous research showing that increased temporal perception was predictive of symptomatology in schizophrenia, particularly auditory hallucinations. Additionally, individuals with more accurate audiovisual speech perception may have higher levels of unusual perceptual experiences, lower levels of suspiciousness, and decreased social anxiety. Individuals with increased ability to read lips may also have lower levels of suspiciousness. This work suggests that abnormal sensory processing may contribute to unusual speech perception associated with schizotypal traits.