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Incongruous pain display as a source of self-deception

University of British Columbia

In some cases of chronic pain, the complaints seem out of proportion to pathophysiological findings. Several models of pain have been forwarded to account for such cases, but no one explanation can account for the underlying processes involved in the genesis of chronic pain in all cases. The present analysis offers the additional factor of self—deception, defined as a contradiction between one’s words or attitude and behavior. By attempting to demonstrate subjective pain to observers, a pain patient convinces him- or herself of the displayed painfulness through a process of self—deception. Several psychological phenomena are included in the model of self—deception, including coping strategies, cognitive dissonance, self-perception, impression management, and attentional and memory biases. To explore the self—deception model of chronic pain, a laboratory analogue study was devised using female student volunteers who rated the painfulness of shock—induced stimuli under conditions designed to foster self—deception. Painfulness was measured 1) verbally by means of two visual analogue scales which reflected the pain intensity and affective unpleasantness and 2) nonverbally by means of quantified facial muscle movements. For each subject, individual pain threshold and tolerance levels were established. She then underwent a pretest comprising five random shocks from her threshold to tolerance range. Next, in the manipulation phase the subject was asked to display more, less or the same degree of pain while undergoing another random series of shocks. A final posttest was identical to the pretest and provided a measure of the durability of the altered pain display effect. In the first of two studies, the altered pain display was nonverbal: subjects exaggerated, diminished or did not change their facial expressiveness while undergoing the pain stimuli. In the second study, the altered pain display was verbal: subjects were told that at the end of the series they would be required to tell a fellow student (via videotape) that the shocks hurt more, less or about the same as what they had expected. Half of all subjects were further told that their deceptive communication would have negative consequences for viewers. Misleading fellow students about the pain experienced was expected to make the subjects feel badly, motivating them to change their attitude or beliefs about the pain experienced. They were expected to change their pain reports in keeping with the deceptive communication. That is, other deception was expected to foster self-deception. This effect was expected to endure and it was expected to be greatest for those in the negative consequences condition. The first study showed that exaggerated facial expressions of pain appear to be an amplification of normal pain expression. However, changes in facial expression did not bring about changes in verbal report of pain perceived, calling into question the facial feedback hypothesis. The results of the second study suggested that pain was altered only for subjects who prepared to state that their pain felt less painful than expected. This effect reached significance on the pain intensity visual analogue scale for low intensity shocks. This effect did not carry over into the posttest phase, nor were negative consequences effective in amplifying the manipulation, leaving the theoretical mechanism underlying the change in pain unclear. Moreover, the effect did not vary amongst subjects who scored differently on questionnaires measuring self—deception as a trait, present anxiety, or adaptive coping strategies. The self—report measure of self—deception was related to factors found to predict adaptive coping or good functioning in chronic pain patients, namely a sense of control over pain and the absence of catastrophizing thoughts. One particular facial movement (brow lowerer) was consistently related to the verbal pain reports, attesting to the validity of facial expression as a measure of pain. The results are discussed with implications and suggestions for future research. One major problem with research involving subject deception is that subjects may appear to comply with experimental instructions to deceive others while avoiding personal responsibility through a variety of mechanisms yet to be determined.

Thesis/Dissertation

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2008-12-23

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http://hdl.handle.net/2429/3295

Psychology

University of British Columbia

UBCV

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