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Expectations modulate heterotopic noxious counter-stimulation analgesia.
Stéphanie Cormier1, Mathieu Piché, Pierre Rainville
1Department of Psychology, Université de Montréal, Montréal, QC, Canada.
The Journal of Pain
|December 25, 2012
Summary
Expectations significantly influence pain relief from heterotopic noxious counter-stimulation (HNCS). Both pre-existing beliefs and suggested expectations can either enhance or block the analgesic effects of HNCS, independent of anxiety.
Area of Science:
- Pain research
- Neuroscience
- Psychology
Background:
- Heterotopic noxious counter-stimulation (HNCS) is a technique used to induce analgesia.
- The role of psychological factors, particularly expectations, in modulating pain perception and analgesic responses is increasingly recognized.
Purpose of the Study:
- To investigate the contribution of both a priori (pre-existing) and manipulated expectations to analgesia induced by HNCS.
- To determine if anxiety mediates the relationship between expectations and HNCS analgesia.
Main Methods:
- Healthy volunteers were assigned to control or experimental groups.
- Expectations were either assessed (a priori) or manipulated via suggestions (hyperalgesia/analgesia).
- Pain perception (acute shock-pain), nociceptive flexion reflex (RIII-reflex), and anxiety were measured during baseline, HNCS, and recovery periods.
Main Results:
- A priori expectations were strongly correlated with the magnitude of HNCS analgesia.
- Suggestions of hyperalgesia increased pain and reflex responses, while suggestions of analgesia decreased them, demonstrating modulation of HNCS effects.
- Anxiety changes correlated with pain and reflex changes but did not mediate the effect of manipulated expectations on analgesia.
Conclusions:
- HNCS analgesia is significantly modulated by expectations, whether they are pre-existing or suggested.
- These findings suggest that expectations can alter descending pain modulation pathways.
- Understanding the role of expectations may be crucial for optimizing pain management strategies and explaining deficits in pain inhibition in chronic pain patients.
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