Impaired perception of vocal emotions in Parkinson's disease: Influence ofspeech time processing and executive functioning

Little is known about the underlying dimensions of impaired recognition of emotional prosody that is frequently observed in patients with Parkinson's disease (PD). Because patients with PD also suffer from working memory defi cits and impaired time perception. the present study examined the contribut ion of (a) working memory (frontal executive functioning) and (b) processin g of the accustic parameter speech rate to the perception of emotional pros ody in PD. Two acoustic parameters known to be important for emotional clas sifications (speech duration and pitch variability) were systematically var ied in prosodic utterances. Twenty pa with PD and 16 healthy controls (matc hed for age, sex, and IQ) participated in the study. The findings imply tha t (1) working memory dysfunctions and perception of emotional prosody are n ot independent in PD. (2) PD and healthy control subjects perceived vocal e motions categorically along two acoustic manipulation continua, and(3) pati ents with PD show impairments in processing of speech rats information. (C) 2001 Academic Press.