Brains respond to acupuncture needles in rubber hands just like real ones
Two pages on PainSci cite Chae 2015: 1. Do You Believe in Qi? 2. Does Acupuncture Work for Pain?
PainSci commentary on Chae 2015: ?This page is one of thousands in the PainScience.com bibliography. It is not a general article: it is focused on a single scientific paper, and it may provide only just enough context for the summary to make sense. Links to other papers and more general information are provided wherever possible.
In this study, subjects had their brains scanned while acupuncture was performed on a “phantom limb,” by tricking the brain into perceiving a rubber hand as if it was real (a well-established technique). In this scenario, the needling cannot possibly cause a biological response. And even if people have qi flowing in meridians, clearly rubber hands do not. And so this experiment neatly eliminates two of the major common explanations for how acupuncture might work.
The results identified the same kind of perceptions and brain activity that previous studies have found with needling of genuine limbs. This (strongly) suggests that the explanation for any perceived benefit of acupuncture is psychological: the brain is responding to the idea of needling. Real needling not required to elicit the same response that has been touted as a specific therapeutic effect. If true, belief is the active ingredient in acupuncture, not the manipulation of qi, or obscure biological effects.
This result is perfectly consistent with the skeptical position on acupuncture.
Dr. Steven Novella wrote a much more detailed analysis of this study: “Phantom Acupuncture.”
original abstract †Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
From a neuroscientific perspective, the sensations induced by acupuncture are not only the product of the bottom-up modulation of simple needling at somatosensory receptors, but also of the reciprocal interaction of top-down modulation from the brain. The present study investigated whether acupuncture stimulation to incorporated body parts produces brain responses that are similar to the responses observed following acupuncture stimulation to the real hand. The present study included 17 participants who watched a rubber hand being synchronously stroked with their unseen left hand to induce incorporation of the rubber hand into their body. After the experimental modification of body ownership, acupuncture needle stimulation was applied to the LI4 acupoint on the incorporated rubber hand while brain activity was measured with functional magnetic resonance imaging (fMRI). When the rubber hand was fully incorporated with the real body, acupuncture stimulation to the rubber hand resulted in the experience of the DeQi sensation as well as brain activations in the dorsolateral prefrontal cortex (DLPFC), insula, secondary somatosensory cortex (SII), and medial temporal (MT) visual area. The insular activation was associated with the DeQi sensation from the rubber hand. The psychophysical and neurophysiological responses associated with acupuncture stimulation to the incorporated rubber hand were influenced by an enhanced bodily awareness of the hand, which was likely due to top-down modulation from the interoceptive system in the brain.
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Specifically regarding Chae 2015:
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- Placebo analgesia in physical and psychological interventions: Systematic review and meta-analysis of three-armed trials. Hohenschurz-Schmidt 2024 Eur J Pain.
- Recovery trajectories in common musculoskeletal complaints by diagnosis contra prognostic phenotypes. Aasdahl 2021 BMC Musculoskelet Disord.
- Cannabidiol (CBD) products for pain: ineffective, expensive, and with potential harms. Moore 2023 J Pain.
- Moderators of the effect of therapeutic exercise for knee and hip osteoarthritis: a systematic review and individual participant data meta-analysis. Holden 2023 The Lancet Rheumatology.
- Inciting events associated with lumbar disc herniation. Suri 2010 Spine J.