Biomedical subjects

Carol L Leonard

Publications and source records attributed to Carol L Leonard.

3 recordsLinked to original sources

PubMed2005

The impact of Parkinson's disease on vocal-prosodic communication from the perspective of listeners.

An expressive disturbance of speech prosody has long been associated with idiopathic Parkinson's disease (PD), but little is known about the impact of dysprosody on vocal-prosodic communication from the perspective of listeners. Recordings of healthy adults (n=12) and adults with mild to moderate PD (n=21) were elicited in four speech contexts in which prosody serves a primary function in linguistic or emotive communication (phonemic stress, contrastive stress, sentence mode, and emotional prosody). Twenty independent listeners naive to the disease status of individual speakers then judged the intended meanings conveyed by prosody for tokens recorded in each condition. Findings indicated that PD speakers were less successful at communicating stress distinctions, especially words produced with contrastive stress, which were identifiable to listeners. Listeners were also significantly less able to detect intended emotional qualities of Parkinsonian speech, especially for anger and disgust. Emotional expressions that were correctly recognized by listeners were consistently rated as less intense for the PD group. Utterances produced by PD speakers were frequently characterized as sounding sad or devoid of emotion entirely (neutral). Results argue that motor limitations on the vocal apparatus in PD produce serious and early negative repercussions on communication through prosody, which diminish the social-linguistic competence of Parkinsonian adults as judged by listeners.

Adult↗

PubMed2005

Facial expression decoding in early Parkinson's disease.

The ability to derive emotional and non-emotional information from unfamiliar, static faces was evaluated in 21 adults with idiopathic Parkinson's disease (PD) and 21 healthy control subjects. Participants' sensitivity to emotional expressions was comprehensively assessed in tasks of discrimination, identification, and rating of five basic emotions: happiness, (pleasant) surprise, anger, disgust, and sadness. Subjects also discriminated and identified faces according to underlying phonemic ("facial speech") cues and completed a neuropsychological test battery. Results uncovered limited evidence that the processing of emotional faces differed between the two groups in our various conditions, adding to recent arguments that these skills are frequently intact in non-demented adults with PD [R. Adolphs, R. Schul, D. Tranel, Intact recognition of facial emotion in Parkinson's disease, Neuropsychology 12 (1998) 253-258]. Patients could also accurately interpret facial speech cues and discriminate the identity of unfamiliar faces in a normal manner. There were some indications that basal ganglia pathology in PD contributed to selective difficulties recognizing facial expressions of disgust, consistent with a growing literature on this topic. Collectively, findings argue that abnormalities for face processing are not a consistent or generalized feature of medicated adults with mild-moderate PD, prompting discussion of issues that may be contributing to heterogeneity within this literature. Our results imply a more limited role for the basal ganglia in the processing of emotion from static faces relative to speech prosody, for which the same PD patients exhibited pronounced deficits in a parallel set of tasks [M.D. Pell, C. Leonard, Processing emotional tone from speech in Parkinson's disease: a role for the basal ganglia, Cogn. Affect. Behav. Neurosci. 3 (2003) 275-288]. These diverging patterns allow for the possibility that basal ganglia mechanisms are more engaged by temporally-encoded social information derived from cue sequences over time.

Aged↗

PubMed2003

Processing emotional tone from speech in Parkinson's disease: a role for the basal ganglia.

In this study, individuals with Parkinson's disease were tested as a model for basal ganglia dysfunction to infer how these structures contribute to the processing of emotional speech tone (emotional prosody). Nondemented individuals with and without Parkinson's disease (n = 21/group) completed neuropsychological tests and tasks that required them to process the meaning of emotional prosody in various ways (discrimination, identification, emotional feature rating). Individuals with basal ganglia disease exhibited abnormally reduced sensitivity to the emotional significance of prosody in a range of contexts, a deficit that could not be attributed to changes in mood, emotional-symbolic processing, or estimated frontal lobe cognitive resource limitations in most conditions. On the basis of these and broader findings in the literature, it is argued that the basal ganglia provide a critical mechanism for reinforcing the behavioral significance of prosodic patterns and other temporal representations derived from cue sequences (Lieberman, 2000), facilitating cortical elaboration of these events.

Affect↗