Cross-modal and modality-specific expectancy effects between pain and disgust

Abstract

Pain sensitivity increases when a noxious stimulus is preceded by cues predicting higher intensity. However, it is unclear whether the modulation of nociception by expectancy is sensory-specific (“modality based”) or reflects the aversive-affective consequence of the upcoming event (“unpleasantness”), potentially common with other negative events. Here we compared expectancy effects for pain and disgust by using different, but equally unpleasant, nociceptive (thermal) and olfactory stimulations. Indeed both pain and disgust are aversive, associated with threat to the organism, and processed in partly overlapping brain networks. Participants saw cues predicting the unpleasantness (high/low) and the modality (pain/disgust) of upcoming thermal or olfactory stimulations, and rated the associated unpleasantness after stimuli delivery. Results showed that identical thermal stimuli were perceived as more unpleasant when preceded by cues threatening about high (as opposed to low) pain. A similar expectancy effect was found for olfactory disgust. Critically, cross-modal expectancy effects were observed on inconsistent trials when thermal stimuli were preceded by high-disgust cues or olfactory stimuli preceded by high-pain cues. However, these effects were stronger in consistent than inconsistent conditions. Taken together, our results suggest that expectation of an unpleasant event elicits representations of both its modality-specific properties and its aversive consequences.

Observe to get pain relief: current evidence and potential mechanisms of socially learned pain modulation

“…Research on somatic and empathic (vicarious) pain can also inform future research on socially-induced placebo (and nocebo) pain modulation. Vicarious and somatic types of pain have commonalities at the neural level [15; 49] with overlapping activations in the dorsal anterior cingulate cortex, anterior insula, and other areas. Nevertheless, these activations appear to be unspecific to pain and rather related to negative affect [16; 31].…”

Cross-modal representations of first-hand and vicarious pain, disgust and fairness in insular and cingulate cortex

“…Thus, the identification of shared or independent activity patterns represents a more stringent assessment of whether two conditions recruit the same or different neuronal processes 30 31 32 33 . Using MVPA, we compared activity patterns from 19 female 7 volunteers when they were subjected to either electrical (painful (Ps)/non-painful (nPs)) or gustatory stimuli (disgusting (Ds)/non-disguting (nDs)), which were carefully matched for subjective unpleasantness 34 (self-related trials). In separate (other-related) trials, they saw a befriended confederate receiving equivalent electrical (Po/nPo) or gustatory (Do/nDo) stimuli 5 .…”

Pharmacological fMRI provides evidence for opioidergic modulation of discrimination of facial pain expressions

“…The design was almost identical to the original version (Cook et al, 2013) except for the types of the morphed expressions (e.g., surprise and fear in Cook et al 2013). In our study, the reasons to morph between pain and disgust instead of other emotions were twofold: 1) these two expressions share some similarities but are still distinct enough to be decoded from each other (Kunz et al, 2013;Sharvit et al, 2015); 2) though few studies have reported naltrexone could modulate aversive stimuli (Murray et al, 2014), it is still considered that the link between disgust and the opioid system is not conclusive (Nummenmaa and Tuominen 2018). In each trial, after 1500 ms fixation, a facial expression was presented on the screen, which consisted of a morph between two original images showing pain and disgust (e.g., 50% pain and 50% disgust) for 800 ms.…”