The theory of the dispositional bases of vocal nodules and functional dysphonia (Roy & Bless, 2000) represents an important step toward the understanding of the relation between personality and voice disorders. However, experimental tests of this theory are widely lacking.
In this study, female healthy and vocally normal adults between the ages of 18-35 years were divided into two groups, introversion (n = 27) and extraversion (n = 27), based on results on the Eysenck Personality Questionnaire- Revised (EPQ-R). Both groups underwent a stress reactivity protocol, which involved a simulated public speaking stressor in addition to baseline speech, rest, and recovery phases.
Participants in the introversion group had significantly higher scores on voice handicap and depression than participants in the extraversion group. The introversion group exhibited significantly greater infrahyoid muscle activity (surface electromyography) and perceptions of vocal effort throughout the protocol. However, although greater stress reactivity was also descriptively observed for those measures in the introversion group, the phase by personality interaction was non-significant as were group differences for submental and anterior tibialis muscle activity. Voice fundamental frequency and intensity significantly decreased during stressor exposure for both groups. The stress induction was effective and significantly increased systolic blood pressure (SBP) and negative affect in everyone. The degree of rumination was not different between groups, but the participants with introversion experienced significantly more fear of public speaking. Neither SBP, negative affect, nor fear of public speaking were significantly correlated with SEMG activity in the participant pool. Instead the trait introversion was significantly and positively correlated with infrahyoid muscle activity in the total sample.
This psychobiological study is first examination of the trait theory of voice disorders to focus on the role of stress reactivity. Results indicated that persons with introversion had a disposition towards increased infrahyoid extralaryngeal muscle activity combined with greater perceptions of vocal effort during speech, which were both magnified under conditions of psychological stress. Findings were tentatively interpreted to be consistent with behavioral inhibition in individuals high on introversion as predicted in the trait theory of voice disorders, which may constitute a risk factor for muscle tension dysphonia.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-04152009-220132 |
| Date | 05 June 2009 |
| Creators | Dietrich, Maria |
| Contributors | Katherine Verdolini Abbott, J. Richard Jennings, Anna L. Marsland, Susan Shaiman, J. Scott Yaruss |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.pitt.edu/ETD/available/etd-04152009-220132/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Pittsburgh or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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