Copyright © The British Psychological Society Reproduction in any form (including the internet) is prohibited without prior permission from the Society Understanding speaker attitudes from prosody by adults with Parkinson’s disease Laura Monetta, Henry S. Cheang and Marc D. Pell* McGill University, School of Communication Sciences and Disorders, Montreal, Quebec, Canada The ability to interpret vocal (prosodic) cues during social interactions can be disrupted by Parkinson’s disease, with notable effects on how emotions are understood from speech. This study investigated whether PD patients who have emotional prosody deficits exhibit further difficulties decoding the attitude of a speaker from prosody. Vocally inflected but semantically nonsensical ‘pseudo-utterances’ were presented to listener groups with and without PD in two separate rating tasks. Task 1 required participants to rate how confident a speaker sounded from their voice and Task 2 required listeners to rate how polite the speaker sounded for a comparable set of pseudo-utterances. The results showed that PD patients were significantly less able than HC participants to use prosodic cues to differentiate intended levels of speaker confidence in speech, although the patients could accurately detect the polite/impolite attitude of the speaker from prosody in most cases. Our data suggest that many PD patients fail to use vocal cues to effectively infer a speaker’s emotions as well as certain attitudes in speech such as confidence, consistent with the idea that the basal ganglia play a role in the meaningful processing of prosodic sequences in spoken language (Pell & Leonard, 2003). Humans typically use verbal and non-verbal signals in tandem to convey information about their mental and affective state to listeners (DePaulo & Friedman 1998). Even in the absence of verbal content, listeners can often decipher a speaker’s affective states, feelings and attitude towards the listener (e.g. expressing sarcasm or approval) by strictly attending to non-verbal indicators such as facial expressions or vocal cues, or speech prosody (Wichmann, 2000). In the vocal channel, sensitivity to prosodic variations over the course of an utterance appears to be essential for interpreting vocal expressions of emotion and certain attitudes in speech (Pell, 2007). Two recurring instances in which listeners must harness prosodic cues to infer the intended attitude of the speaker are to determine the relative confidence of a speaker in what they are saying (confident/doubtful) and the relative politeness of the speaker * Correspondence should be addressed to Marc D. Pell, 1266 avenue des Pins Ouest, Montreal, Canada (e-mail: marc.pell@mcgill.ca). The British Psychological Society 415 Journal of Neuropsychology (2008), 2, 415–430 q 2008 The British Psychological Society www.bpsjournals.co.uk DOI:10.1348/174866407X216675