Lexical tone and consonant perception in subtypes of Schizophrenia

Abstract

Auditory hallucination is one of diagnostic criteria of schizophrenia and might negatively affect speech perception. Among subtypes of schizophrenia, the persistent delusion/hallucination (PDH) group persistently shows auditory hallucinations after 6 months of admission. This study aims to examine whether hallucinations affect lexical tone and consonant perception in Mandarin-speaking adults. Two groups of adults with chronic schizophrenia, PDH (n =15, mean age = 44 yr) and non-hallucination group (n =17, mean age = 39 yr), and age-matched control group (n = 16, mean age = 36 yr) in Taiwan were tested. For lexical tone perception, results showed that adults with schizophrenia were less accurate than typical controls on discriminating the lexical tones, and the PDH group performed poor than patients without hallucination. The lexical tone accuracy negatively correlates with the severity of schizophrenic symptoms (r = −0.559, p < 0.001, measured with Positive and Negative Syndrome Scale for schizophrenia). For consonant perception, patient groups showed poor perceptual organizations for affricates than control group. Moreover, the perceptual organization of PDH group is more distorted than non-hallucination group. In brief, adults with chronic schizophrenia exhibit speech perception deficits, and these deficits might be the result of a distorted perceptual organization.