Socially induced placebo analgesia: A comparison of a pre-recorded versus live face-to-face observation

摘要

Background Recently, it has been shown that live, face-to-face social observation induces marked placebo analgesia. Despite the phenomenal growth of video sharing platforms, the potential analgesic effects of video-based social observation are largely unknown. This study compared video-based and live social observation induced placebo analgesia and whether there was a similar relationship between analgesic responses and empathy traits for both conditions. Methods Here, we compared placebo analgesia in four groups: social observation through a video (SOV group), social observation in person (SOP group), verbal suggestion alone (VS group) and a natural history group (NH group). The SOV and SOP groups underwent a placebo treatment and painful stimuli following respectively a video-based and live observation of a demonstrator showing analgesic effects when the painful stimuli were paired to a green light but not a red light. The VS group received painful stimuli after they had been verbally instructed to expect less pain after the green light. The NH group received painful stimuli, but was told nothing about the meaning of the lights. Individual pain reports and empathy traits were measured. Results We found that video-based observation induced substantial placebo analgesic responses that were of similar magnitude to live observation. Notably, the analgesic scores were strongly correlated with empathetic concern in the live observation group but not in the video replay group. Conclusions These findings add evidence that placebo analgesia can be induced by social observation and that empathy interacts with these effects in a context-dependent manner.