Mechanisms of sustained placebo analgesia: fMRI identifies involvement of non-pain processes

Abstract

Placebo analgesia (PA) is a complex phenomena known to influence the neural activity in pain-related brain regions (e.g., thalamus, insula, ACC, etc.). Previously, we identified different neural networks, top-down processes, and self-enhancing feedback mechanisms associated with PA. However, our understanding of endogenous pain modulation is incomplete. To better understand the neural mechanisms involved in sustaining the PA response longitudinally, we used fMRI and thermal stimuli to identify brain regions significantly more involved in PA compared to pain related processes.