UCL Speech Science Forum
28 October 2015, 4pm, G10
PRODUCTION AND PERCEPTION OF EMOTIONAL PROSODY: THE CASE OF
AUTISM AND PARKINSON’S DISEASE
Cristiane Hsu
Abstract
The current study aims to investigate the acoustic correlates of the production and perception
in emotional and attitudinal prosody of adolescents with autism (ASD) and Parkinson’s disease
(PD) patients. It has been widely accepted among speech therapists that, although from very
different aetiologies, individuals with ASD or PD speak with deviant prosodic patterns,
monopitch, wrong stress, and greater difficulties in expressing emotions through prosody,
while their perception of emotion and attitude is also jeopardised. However, when comparing
their performance with their respective peers, results were far from consistent, ranging from
significant poorer to similar performance level.
This disparity in findings may emerge from disease severity, task type, and research method.
Therefore, in the present study, these issues were systematically controlled. Only individuals
with mild to moderate ASD or PD were included to the experimental groups. Synthetic speech
was used to generate auditory stimuli for the perceptual tasks, allowing precise manipulations
of acoustic parameters. The use of designed sentence to elicit speech provided better
comparison across speakers.
The major innovation of this study is the use of bio-informational dimension (BID) theory as
the theoretical framework. BID dimensions include body-size projection, dynamicity,
audibility and association. Body-size projection associates high pitch with submissiveness,
friendliness, politeness, vulnerability, and low pitch with dominance, confidence, protection,
aggressiveness. This research paradigm has been proven to be effective in several studies
examining the perception of emotional prosody. The hypotheses of the present study were
made based on body-size projection.
The main findings of this study include 1) both adolescents with ASD and PD patients
performed poorer than their controls in the perceptual judgement of emotional and attitudinal
prosody; 2) only their expressive skills in emotional prosody was comparable to their controls;
3) their performance in attitudinal prosody was worse than their controls.