Master of Science (MSc)
Faculty of Science
Dr. Jeffery Jones
Objective: It is known that autistic individuals have enhanced abilities in pitch discrimination and tend to excel in low-level tasks requiring lower cognitive processing. On the other hand, noise is a distracting factor in many areas of life, including prosody perception. The studies presented in this thesis aimed to understand prosody perception through different levels of cognitive tasks and under the influence of speech background noise.
Methods: In total, 256 non-autistic and 39 high-functioning autistic adults participated in these studies. In the first study, participants were asked to listen to brief utterances conveying one of six universally accepted emotions (happy, sad, angry, surprise, disgust, fear) and match it to a corresponding facial expression at three levels of auditory babble background noise conditions; 0 dB, -3 dB and -6 dB. In the second study, participants were asked to complete a pitch discrimination task between 180-200 Hz. In addition, they were asked to listen to five basic emotional utterances (happy, sad, angry, surprise, neutral) and determine the direction of the utterance, as well as the emotion conveyed in these statements to examine the effects of task-dependent performance.
Results: ANOVA results indicated that both autistic and non-autistic participants had similar performance in emotional recognition under all three noise conditions. In addition, a mixed ANOVA revealed no group differences in pitch discrimination, sentence direction identification and emotion recognition tasks. However, a significant effect of emotion was observed. It was found that some emotions are recognized more easily compared to other emotions in both autistic and non-autistic groups. In addition, ANOVA results showed that individuals who had music training performed better at pitch discrimination and emotion perception tasks but not in sentence direction tasks which asked participants to identify the direction of each utterance.
Conclusion: These findings suggest that high-functioning autistic adults may have intact prosody perception abilities yielding them to perform as well as non-autistic adults even under noise conditions. Some emotions are perceived more easily compared to others regardless of diagnosis. Music training may allow adults to discriminate the pitch of sweep tones and perceive emotions more correctly compared to those without music training.
Sasal, Zehranur, "Examining the Effects of Noise and Task Dependent Performance in Prosody Perception in Autistic Individuals" (2023). Theses and Dissertations (Comprehensive). 2562.