Enhanced pain-related conditioning for face compared to hand pain

Abstract

Pain is evolutionarily hardwired to signal potential danger and threat. It has been proposed that altered pain-related associative learning processes, i.e., emotional or fear conditioning, might contribute to the development and maintenance of chronic pain. Pain in or near the face plays a special role in pain perception and processing, especially with regard to increased pain-related fear and unpleasantness. However, differences in pain-related learning mechanisms between the face and other body parts have not yet been investigated. Here, we examined body-site specific differences in associative emotional conditioning using electrical stimuli applied to the face and the hand. Acquisition, extinction, and reinstatement of cue-pain associations were assessed in a 2-day emotional conditioning paradigm using a within-subject design. Data of 34 healthy subjects revealed higher fear of face pain as compared to hand pain. During acquisition, face pain (as compared to hand pain) led to a steeper increase in pain-related negative emotions in response to conditioned stimuli (CS) as assessed using valence ratings. While no significant differences between both conditions were observed during the extinction phase, a reinstatement effect for face but not for hand pain was revealed on the descriptive level and contingency awareness was higher for face pain compared to hand pain. Our results indicate a stronger propensity to acquire cue-pain-associations for face compared to hand pain, which might also be reinstated more easily. These differences in learning and resultant pain-related emotions might play an important role in the chronification and high prevalence of chronic facial pain and stress the evolutionary significance of pain in the head and face.

Motor Learning in Response to Different Experimental Pain Models Among Healthy Individuals: A Systematic Review

“…The titles and abstracts of 3075 studies were screened after removing 425 duplicates. The full text of 26 studies ( Bonifazi et al, 2004 ; Boudreau et al, 2007 , 2010 ; Ingham et al, 2011 ; Bouffard et al, 2014 , 2016 , 2018 ; Dancey et al, 2014 , 2016a , b , 2018 , 2019 ; Lamothe et al, 2014 ; Rosati et al, 2014 ; Bilodeau et al, 2016 ; Boselie et al, 2016 ; Mancini et al, 2016 ; Mista et al, 2016 ; Brun et al, 2017 ; Mavromatis et al, 2017 ; Billot et al, 2018 ; Gallina et al, 2018 , 2021 ; Alaiti et al, 2020 ; Schmidt et al, 2020 ; Arieh et al, 2021 ) were assessed in agreement with the inclusion and exclusion criteria in which only 16 studies ( Boudreau et al, 2007 , 2010 ; Ingham et al, 2011 ; Bouffard et al, 2014 , 2016 , 2018 ; Dancey et al, 2014 , 2016a , b , 2018 , 2019 ; Lamothe et al, 2014 ; Bilodeau et al, 2016 ; Mavromatis et al, 2017 ; Gallina et al, 2018 ; Arieh et al, 2021 ) were included in this review. Finally, one study ( Salomoni et al, 2019 ) was added through a hand-searching of the citations of the relevant studies through Google Scholar; thus, 17 studies were included in this review ( Figure 1 ).…”

Does pain modality play a role in the interruptive function of acute visceral compared with somatic pain?

“…When performing analyses of the development of pain unpleasantness ratings, including random slopes did not improve 49). Moreover, as expected, because of previous reports on higher pain unpleasantness at comparable intensity levels for visceral then somatic pain, pain intensity ratings were significantly lower for visceral pain with a medium effect size (D b 5 10.75 6 4.18 [95% CI 18.13-3.36]; t[121.02] 5 2.57, P 5 0.01, d 5 0.47) but there were no significant differences between conditions in the development of pain intensity over time (D b 5 2 0.69 6 0.77 [95% CI 22.34 to 0.96]; t[329.00] 5 20.90, P 5 0.37, d 5 20.10).…”

“…36 Top-down factors, such as the expectation of pain-related impairment 13,53,54 or fear of pain, 7 as well as bottom-up factors, like the affected body site, likely determine the extent of pain-cognition interference. For example, experimental pain stimuli applied to the hand versus the face elicited different levels of pain-related fear 49,51,52 and differentially interfered with visual encoding and memory performance. 50,51 However, all of these studies used exteroceptive rather than interoceptive experimental models of acute pain.…”

Impaired pain-related threat and safety learning in patients with chronic back pain

“…This allowed us to capture the temporal dynamics of pain-related threat and safety learning. 56 Changes in CS valence were assessed during every fourth CS 1 /CS 2 presentation through a 250 to 150 VAS with the question "How do you perceive this geometric figure?" (anchors: 250 5 "very pleasant," 0 5 "neutral," and 150 5 "very unpleasant").…”

“…Differential and nondifferential learning (ie, threat and safety learning) were investigated using separate linear mixed models (LMMs) on valence ratings, as implemented in the R package lme4. 56 To compare DCS valence ratings and their changes over time between patients with CBP and HCs, the factors time and group (HCs and patients with CBP), as well as interactions of these factors, were included as fixed effects into the models. The factor time was included as a continuous factor to account for increases or decreases of DCS valences during the experiment.…”