Interpersonal influences on pain expressions
Creators: name: Prkachin, Kenneth Martin
Publisher: name: University of British Columbia
Year: 2010

description: Increasing evidence suggests that social experiences critically determine the manner in which individuals respond to painful events. Of the variety of social determinants of pain responses, social modeling has been among the most extensively studied. Conclusive evidence is available showing that exposure to models who exhibit tolerance or intolerance for noxious electrical stimulation produces matching behaviour on the part of subjects. However, questions related to the breadth of the changes induced, and the applicability of these findings to naturally-occurring painful experiences require further investigation. The present series of studies examined some of these issues. Experiment 1 re-evaluated the impact of social modeling on sensory-decision theory (SDT) indices of the response to pain. Following a baseline pre-assessment of pain threshold and tolerance, 30 female subjects were exposed to models displaying tolerance or intolerance for the stimulation, or an inactive companion. Under conditions of influence, subjects' behaviour approximated that of the model. After these effects had been induced, subjects underwent a SDT series during which they were exposed to stimuli from low, moderate, and high levels of current intensity. Results indicated that intolerant modeling was associated with increased sensory sensitivity at noxious levels of stimulation. Tolerant modeling was not associated with differential values of sensitivity-, suggesting that previous positive findings be qualified. Experiment 2 was concerned with the effects of tolerant and intolerant modeling on overt expressive displays. Videotapes taken of subjects in Experiment 1 were presented to 15 female observers who attempted to predict the levels of current that observed subjects were experiencing. SDT analyses of observers' judgments indicated that responses to intense stimuli were more readily discriminated than responses to less intense stimuli. The behaviour of subjects exposed to a tolerant model was less discriminable than that of intolerant subjects. The behaviour of intolerants was less discriminable than that of controls. It was argued that tolerant modeling produces reductions in overt; nonvocal expressions of pain. Experiment 3 examined whether modeling effects could be obtained with naturally-occurring groups, and the relative power of pain tolerant and intolerant behaviour. 127 female undergraduates underwent a screening for pain threshold levels. In a subsequent session, subjects participated either individually, or in pairs comprised of all combinations of subjects having high and low thresholds. Unidirectional influence was observed, with low threshold subjects inducing high threshold subjects to report pain sooner, and accept fewer currents. These results indicated that pain intolerant behaviour may be a more powerful social influence than pain tolerant behaviour, probably as a result of its imperative nature. Since the modeling effect was observable among naturally-occurring groups, the generalizability of laboratory to naturally-occurring pain phenomena was supported. Relationships between measures of pain based on psychophysical judgments and overt behaviour were examined within the context of a model that suggests that inducing alterations in pain behaviour may modulate the experience of pain.