A substantial amount of research has investigated the psychophysiological profiles of various mood and emotional states; however, very little research has investigated individuals� mood responses from a psychophysiological perspective. As a result, little is known about the psychophysiological reactivity of individuals to various mood-related responses, or the ability of psychophysiological measures to differentiate between response styles. Furthermore, most investigations in the area of mood-related response styles have relied on participants self-report responses of their mood reactivity, which is considered to be susceptible to demand characteristics and response bias. Psychophysiological measures are thought to offer a unique and alternative measure of mood reactivity that can corroborate, or challenge self-report findings. They are considered to be less susceptible to demand effects than self-report, and can detect subtle changes in mood reactivity activity when an overt response is not apparent. In view of this, the primary objective of this thesis was to move beyond a reliance on subjective self-report measurements of mood reactivity, and to investigate the consequences of depressed mood-related cognitive response styles from a psychophysiological perspective. As part of this investigation, this thesis aims to address a number of theoretical and practical questions relating to the use of psychophysiological measures in mood research and clinical practice.
The research is divided into four studies, each one focusing on a particular aspect of the investigation.
The aim of Study 1 was to select and trial a laboratory-based mood induction procedure (MIP) and a self-report mood measure, with the intention of developing a reliable method of inducing and measuring depressed mood. Two film clips that contained either positive or negative affective content were presented to participants. Self-report responses on the Mood Scale confirmed that the negative film clip elicited a very unpleasant mood state with high emotional arousal, and that the positive film clip elicited a mildly pleasant mood state with low emotional arousal. The positive and negative Film Clip MIPs were then used in Studies 2 and 2a, to investigate participants� psychophysiological reactivity to induced mood.
The aim of Studies 2 and 2a was to identify a set of psychophysiological measures that would differentiate between participants� mood states. In Study 2, the positive and negative Film Clip MIPs, from Study 1, were again presented to participants. Corrugator supercilii facial EMG activity, zygomaticus major facial EMG activity, skin conductance activity (SCA), heart rate (plethysmograph, sphygmomanometer), systolic blood pressure, diastolic blood pressure, and self-report ratings on the Mood Scale were recorded. Results confirmed that participant self-reported affective responses were similar to those reported in Study 1; however, mixed results were obtained in regards to individuals� psychophysiological responses to the MIPs. Facial EMG activity and heart rate (plethysmograph) were consistent with participants� self-reported mood, whereas, SCA and systolic blood pressure were inconsistent with participants� self-reported mood. Diastolic blood pressure and heart rate (sphygmomanometer) did not differentiate between the MIPs. As the results were somewhat contradictory to expectations, it was decided to further investigate the psychophysiology of induced mood in Study 2a, using a revised set of psychophysiological measures.
In Study 2a, the positive and negative Film Clip MIPs were again presented to participants. Corrugator supercilii facial EMG activity, zygomaticus major facial EMG activity, SCA, heart rate (ECG), and finger temperature, were recorded along with participants� Mood Scale ratings. It was found that facial EMG activity and SCA, paralleled participant self-report as expected, and were most responsive to participants� change in mood state. Heart rate (ECG) and finger temperature did not clearly differentiate between the induced mood states.
The aim of Study 3 was to conduct an experimental, laboratory-based investigation, into the psychophysiological and subjective mood consequences of two cognitive response styles: self-focused depressive rumination and external-focused distraction. As in the previous study, the negative Film Clip MIP and the Mood Scale were used to induce depressed mood and to measure participants� subjective mood state. Psychophysiological reactivity was recorded by measuring participants� corrugator supercilii facial EMG, zygomaticus major facial EMG, SCA, heart rate (sphygmomanometer), systolic blood pressure, and diastolic blood pressure. Trait response style was measured using the Response Style Questionnaire (RSQ; Nolen-Hoeksema & Morrow, 1991) and social desirability was measured using the Marlowe Crowne-Social Desirability Scale (MC-SDS; Crowne & Marlowe, 1960). As predicted by the Response Style Theory of depression (RST), increased self-reported negative mood was found when participants responded to the induced depressed mood, using a self-focused depressive rumination response style, rather than an external-focused distraction response style. Psychophysiological activity increased over the course of the negative Film Clip MIP for all psychophysiological measures, however, only corrugator supercilii facial EMG activity clearly differentiated between the cognitive response styles, in a way predicted by individuals� self-report responses. There was no evidence of a relationship between participants� trait response style and their psychophysiological reactivity or mood responses during the experiment. However, individuals high in trait rumination reported greater depressive symptomatology, and less mood reactivity during the experiment, than those high in trait distraction. Furthermore, participants� ratings of social desirability were positively associated with their level of depressive symptomatology and trait rumination.
The aim of Study 4 was to conduct a pilot study to investigate the psychophysiological consequences of two further cognitive response styles: negative automatic thoughts and positive autobiographical recall. A series of twelve single-case (ABC-ABC) experiments were carried out using a procedure analogous to a clinical therapy process. Initially a depressed Story MIP was used to induce a depressed mood in participants (A). Participants were then required to respond to their depressed mood using negative self-statements (B), and positive autobiographical recall (C). Consistent with previous studies, zygomaticus major facial EMG and corrugator supercilii facial EMG clearly paralleled participants� mood reactivity throughout the experiment, whereas SCA and heart rate showed less consistent patterns of reactivity.
This thesis has made an important contribution to mood and psychophysiological research by presenting the first in-depth investigation into the psychophysiological consequences of how people respond to depressed mood, from both a theoretical and a clinical perspective. It is anticipated that the findings of this research will bring about further investigation into the comparative efficacy of various brief mood-related cognitive intervention techniques, which will ultimately assist scientist-practitioners in selecting suitable brief cognitive intervention techniques for helping clients ameliorate their negative mood, emotional, and cognitive states.
| Identifer | oai:union.ndltd.org:ADTP/217386 |
| Date | January 2006 |
| Creators | Donaldson, Bruce William, n/a |
| Publisher | University of Otago. Department of Psychology |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | http://policy01.otago.ac.nz/policies/FMPro?-db=policies.fm&-format=viewpolicy.html&-lay=viewpolicy&-sortfield=Title&Type=Academic&-recid=33025&-find), Copyright Bruce William Donaldson |
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