Placebo analgesia does not reduce empathy for naturalistic depictions of others’ pain in a somatosensory specific way

Abstract

The shared representations account postulates that sharing another’s pain recruits underlying brain functions also engaged during first-hand pain. Critically, direct causal evidence for this has been mainly shown for affective pain processing, while the contribution of somatosensory processes to empathy remains controversial. This controversy may be explained, however, by experimental paradigms that did not direct attention towards a specific body part, or that did not employ naturalistic depictions of others’ pain. In this preregistered fMRI study, we aimed to test whether a causal manipulation of first-hand pain affects empathy for naturalistic depictions of pain in a somatosensory-matched manner. Forty-five participants underwent a placebo analgesia induction in the right hand and observed pictures of right vs. left hands in pain. We found neither behavioral nor neural evidence for somatosensory-specific modulation of empathy for pain. However, exploratory analyses revealed a general effect of the placebo on empathy, and higher brain activity in bilateral anterior insula when viewing other’s hands in pain corresponding to one’s own placebo hand. These results refine our knowledge regarding the neural mechanisms of empathy for pain, and imply that the sharing of somatosensory representations seems to play less of a causal role than the one of affective representations. See also the matching Twitter thread.

Publication
BioRxiv

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