Emotional speech in Parkinson's disease


  • The NTID (Ref.27) is a scale assessing intelligibility of dysarthric or aphasic patients from point 1 (speech is unintelligible) to point 5 (speech is fully intelligible). This scale is used in clinical neuropsychology to cursorily evaluate the degree of the speech disorder.


Patients with Parkinson's disease (PD) tend to speak monotonously with minor modulation of pitch and intensity. The goal of this study was to find out whether these speech changes can be explained mainly by motor impairment, i.e. akinesia and rigidity of the articulatory apparatus, or whether alterations of emotional processing play an additional role. Sixteen patients with mild PD and 16 healthy controls (HC) were compared. Fundamental frequencies (pitch) and intensities (loudness) were determined as (1) maximal upper and lower values achieved in nonemotional speech (phonation capacity), (2) upper and lower values used when speaking “Anna” in emotional intonation (neutral, sad, happy) as requested (production task), or (3) when imitating a professional speaker (imitation task). Although groups did not significantly differ in their phonation capacity, patients showed a significantly smaller pitch and intensity range than HC in the production task. In the imitation task, however, ranges were again similar. These results suggest that alterations of emotional processing contribute to speech changes in PD, especially regarding emotional prosody, in addition to motor impairment. © 2008 Movement Disorder Society