Speech-on-speech masking and psychotic symptoms in schizophrenia

People with schizophrenia have impairments of target-speech recognition (TSR) in noisy environments with multiple people talking. This study investigated whether the TSR impairment in schizophrenia is associated with their impaired auditory working memory or certain psychotic symptoms. Thirty participants with schizophrenia (mean age= 35.2 ± 12.7 years) and 30 demographics-matched healthy controls (mean age= 32.9 ± 10.9 years) were tested for their TSR against a two-talker-speech masker. Auditory working memory and memory capacity were evaluated using the Paced Auditory Serial Addition Test (PASAT) and Digit Span Test. Psychotic symptoms were evaluated using the Positive and Negative Syndrome Scale (PANSS). The results showed that participants with schizophrenia had higher TSR threshold (i.e., poorer TSR performance) and poorer PASAT scores than their healthy controls. Moreover, positive correlations (with age, sex, educational years, ill-duration, and dosage of antipsychotics controlled as covariates) were revealed between the TSR threshold and the PANSS-positive syndrome (especially delusion), and between the TSR threshold and the PANSS-negative syndrome (especially lack of spontaneity in speech and passive-apathetic-social withdraw). However, neither the PASAT nor the forward digit span exhibited significant correlations with the TSR. This study provides evidence that the TSR impairment (i.e., augmented vulnerability to informational speech masking), which reflects disorganization of speech information processing (inability in either inhibiting unrelated speech signals or capturing the wanted speech signals), is specifically associated with the severity of delusion, poverty of speech, and hypobulia, suggesting the potential value of the TSR impairment used for predicting certain core symptoms of schizophrenia. People with schizophrenia exhibit impairments of target-speech recognition (TSR) in noisy environments with multiple people talking (Wu et al., 2012, 2017a, b; Zheng et al., 2016), indicating the deficits in perceptual segregation between target-speech and masking-speech signals. So far, whether this impairment is associated with certain psychotic symptoms has not been reported in the literature. One hypothesis is that the impairment of TSR against informational speech masking in people with schizophrenia may be related to their deficits in auditory working memory and/or in capacity and rate of information processing (Townsend et al., 2001), affecting their performance in tasks that demand divided attention and/or dual processing (Fuller and Jahanshahi, 1999; Wylie et al., 2010). Another hypothesis is that this TSR impairment, which reflects disorganization of speech information processing (inability in either inhibiting unrelated speech signals or capturing the wanted speech signals), may be correlated to thought or speech-processing related symptoms. In this study, 30 patients with schizophrenia (mean age=35.2 ± 12.7 years) and 30 demographics-matched healthy controls (mean age= 32.9 ± 10.9 years) were recruited for examining these hypotheses (Table S1 in Online Supplementary Data presents the main characteristics of these two participant groups). The procedures were approved by the Independent Ethics Committee (IEC) of the Beijing Anding Hospital. Materials (on-line Supplementary material) of this study were similar to those used in our previous studies (Wu et al., 2012, 2017a). Participants were tested for their TSR against a two-talker-speech masker. Auditory working memory and memory capacity were evaluated using the Paced Auditory Serial Addition Test (PASAT) (Correia, 2011; Surhone et al., 2010) and Digit Span Test. Psychotic symptoms were evaluated using the Positive and Negative Syndrome Scale (PANSS). Scores for the five dimensions of PANSS (Mass et al., 2000) were calculated. Partial correlation analyses (with age, sex, educational https://doi.org/10.1016/j.scog.2018.02.005 Received 13 February 2018; Received in revised form 20 February 2018; Accepted 22 February 2018 ⁎ Corresponding author at: School of Psychological and Cognitive Sciences, Peking University, 52 Haidian Road, Beijing 100080, China. E-mail address: [email protected] (L. Li). Schizophrenia Research: Cognition 12 (2018) 37–39 2215-0013/ © 2018 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/). T