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

Acute pain captures attentional resources and interferes with ongoing cognitive processes, including memory encoding. Despite broad clinical implications of this interruptive function of pain for the pathophysiology and treatment of chronic pain conditions, existing knowledge exclusively relies on studies using somatic pain models. Visceral pain is highly prevalent and seems to be more salient and threatening, suggesting that the interruptive function of pain may be higher in acute visceral compared with somatic pain. Implementing rectal distensions as a clinically relevant experimental model of visceral pain along with thermal cutaneous pain for the somatic modality, we herein examined the impact of pain modality on visual processing and memory performance in a visual encoding and recognition task and explored the modulatory role of pain-related fear and expectation in 30 healthy participants. Despite careful and dynamically adjusted matching of stimulus intensities to perceived pain unpleasantness over the course of trials, we observed greater impairment of cognition performance for the visceral modality with a medium effect size. Task performance was not modulated by expectations or by pain-related fear. Hence, even at matched unpleasantness levels, acute visceral pain is capable of interfering with memory encoding, and this impact seems to be relatively independent of pain-related cognitions or emotions, at least in healthy individuals. These results likely underestimate the detrimental effect of chronic pain on cognitive performance, which may be particularly pronounced in acute and chronic visceral pain.