Speech prosody abnormalities and specific dimensional schizotypy features: are relationships limited to male participants?

In schizophrenia, diminished vocal expressivity is associated with lower quality of life. Studies using computerized acoustic analysis of speech have found no evidence of diminished vocal prosody related to categorically defined schizotypy, a subclinical analogue of schizophrenia. However, existing studies have not examined the interaction between schizotypy and sex with vocal prosody measures. The current study examined 44 young adults (50% men) who were recruited to represent a continuous range of schizotypy. Speech samples were digitally recorded during autobiographical narratives and analyzed for prosody. In the male participants, variability of fundamental frequency and variability of intensity were each negatively related to the Schizotypal Personality Questionnaire (SPQ) ideas of reference subscale, whereas SPQ suspiciousness was related to a greater number of utterances, and SPQ odd behavior was related to a greater number of pauses. Because the relationships were restricted to men, and not significant in women, the results may explain earlier negative findings with schizotypy.