title: Can the Acoustic Analysis of Expressive Prosody Discriminate Schizophrenia?
abstract: Emotional states, attitudes and intentions are often conveyed by modulations in the tone of voice. Impaired recognition of emotions from a tone of voice (receptive prosody) has been described as characteristic symptoms of schizophrenia. However, the ability to express non-verbal information in speech (expressive prosody) has been understudied. This paper describes a useful technique for quantifying the degree of expressive prosody deficits in schizophrenia, using a semi-automatic method, and evaluates this method's ability to discriminate between patient and control groups. Forty-five medicated patients with a diagnosis of schizophrenia were matched with thirty-five healthy comparison subjects. Production of expressive prosodic speech was analyzed using variation in fundamental frequency (F0) measures on an emotionally neutral reading task. Results revealed that patients with schizophrenia exhibited significantly more pauses (p < .001), were slower (p < .001), and showed less pitch variability in speech (p < .05) and fewer variations in syllable timing (p < .001) than control subjects. These features have been associated with «flat» speech prosody. Signal processing algorithms applied to speech were shown to be capable of discriminating between patients and controls with an accuracy of 93.8%. These speech parameters may have a diagnostic and prognosis value and therefore could be used as a dependent measure in clinical trials.
authors.affiliation: Universidad de Murcia (Spain).
authors.forename: Francisco
authors.initials: F
authors.lastname: Martínez-Sánchez
authors.affiliation: Universidad de Jaén (Spain).
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Muela-Martínez
authors.affiliation: Universidad de Jaén (Spain).
authors.forename: Pedro
authors.initials: P
authors.lastname: Cortés-Soto
authors.affiliation: Universidad de Salamanca (Spain).
authors.forename: Juan José
authors.initials: JJ
authors.lastname: García Meilán
authors.affiliation: Universidad de Murcia (Spain).
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Vera Ferrándiz
authors.affiliation: Universidad de Murcia (Spain).
authors.forename: Amaro
authors.initials: A
authors.lastname: Egea Caparrós
authors.affiliation: Universidad de Murcia (Spain).
authors.forename: Isabel María
authors.initials: IM
authors.lastname: Pujante Valverde
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D012559:Schizophrenia / Q000175:diagnosis*; D012564:Schizophrenic Language; D012565:Schizophrenic Psychology; D013061:Speech Acoustics
keywords: Schizophrenia; expressive prosody; flat affect; speech analysis