Expectations modulate long‐term heat pain habituation

Abstract

Habituation to pain was shown to be a complex mechanism involving the pain encoding regions and the antinociceptive system in the brain. Pain perception can be modulated by cognitive factors; however it is unclear whether cognitive factors also influence habituation to pain. We used an established experimental design with repetitive moderate painful heat stimulation over eight consecutive days. Thirty-seven healthy subjects were recruited and assigned to four different groups: The first group (n=10) was instructed that pain perception over time will habituate; the second group (n=9) that pain will increase; the third group (n=8) was instructed that pain will remain stable over the 8 days of pain stimulation and the fourth group (n=10) was not given any specific information and served as a control group. We found that the control group habituated as described before. However, it was abolished in the second (sensitize) and third (stable) group, but was very strongly demonstrated in the first (habituation) group. In this group, habituation tended to be increased as compared to the control group. In conclusion, our findings highlight the importance of context information in pain studies and contribute to our knowledge about pain processing and behaviour.

The Nocebo Effect and Its Relevance for Clinical Practice

“…These behavioral changes are supported by objective psychopharmacological (2, 28) and neuroimaging results (27, 29). On one hand, proglumide, a mixed cholecystokinin (CCK) type-A/B receptor antagonist, blocks nocebo hyperalgesic responses following the administration of placebos along with the verbal suggestion of increased pain, thus suggesting a specific involvement of the cholecystokinergic system in nocebo hyperalgesia (2, 28).…”

An Improved Model of Heat-Induced Hyperalgesia—Repetitive Phasic Heat Pain Causing Primary Hyperalgesia to Heat and Secondary Hyperalgesia to Pinprick and Light Touch

“…Since heat-sensitive nociceptors do not only sensitize, but also exhibit prominent fatigue of action potential discharge during sustained or repeated heat stimulation, which needs at least ten minutes for full recovery [29], [35], [36] we conclude that the full expression of heat sensitization only becomes apparent, when nociceptor fatigue has fully subsided and thus the sensitization prevails. A gradual development of primary afferent sensitization [37]–[39], which is limited to the stimulated site is the most likely factor contributing to the observed homotopic sensitization [40], [41],[42]. In agreement with most previous studies [4], [6], [43]–[45] no appreciable changes of heat pain thresholds or heat-induced pain ratings to suprathreshold stimuli could be observed in areas adjacent to the conditioned site and strongly argue against the induction of secondary heat hyperalgesia by our model.…”

Brain correlates of short‐term habituation to repetitive electrical noxious stimulation

“…Positive expectation of a painful stimulus reduces the intensity of pain experience (Koyama et al., ; Keltner et al., ). Recently, it has been shown that positive, negative or neutral expectations of the pain intensity are critically important for the process of habituation (Rodriguez‐Raecke et al., ; Doganci et al., ). In the current study, test persons were blinded for the purpose of the study and for the intended effect of habituation.…”