Yes, pain can be "a self-fulfilling prophecy." We think about it and the pain comes. This brain imaging research, conducted by neuroscientists at the University of Colorado at Boulder, shows that when we expect pain, even if the stimulus isn't painful, we experience pain. The study, presented in the journal Nature Human Behavior, also shows that these misguided prophecies can persist, and with them the associated pain, even when reality repeatedly shows otherwise.
Thus, our expectations regarding the intensity of pain can be self-fulfilling: the study even shows via MRI a positive feedback loop between these expectations and perceived pain. Lead author Dr. Tor Wager, a professor of psychology and neuroscience at the University of Colorado sums it up this way: “The more pain you expect to experience, the more your brain responds to pain. The more your brain reacts to pain, the more you expect from it.”
The hypothesis of a self-fulfilling prophecy regarding pain has “worked” neuroscientists for decades. While multiple studies have already suggested that our expectations can influence our health, including, for example, our response to treatment, this new research is the first to directly model this feedback loop dynamic between our expectations and the pain experienced, and to decipher the underlying neural mechanisms.
The study is conducted here with 34 subjects, who learned to associate a symbol with a low temperature and another symbol with an intense and painful heat. The subjects then had functional magnetic resonance imaging (fMRI), which measures blood flow in the brain, a hallmark of neural activity. For 60 minutes, participants were presented with low or high pain indices and then asked to rate the level of pain expected. Finally, they underwent the application of different degrees of painful heat to the forearm or leg, the highest temperature corresponding "to that of a cup of hot coffee". The study shows that:
- when the subjects expect a high and therefore more painful temperature, the brain regions involved in fear and threat are activated during this expectation;
- the areas involved in the generation of pain are activated in turn;
- suggesting that expectations had a rather profound effect, influencing how the brain processes pain.
- expectations also seem to strongly influence the ability of subjects to learn from their experiences; thus many subjects have a high "bias" despite their previous experiences. High expectations thus seem to reduce the ability to learn – with regard to the sensation of pain.
Implications for recovery from painful conditions? These results suggest that expectations about pain and even treatment outcomes may, in some situations, influence optimal recovery. Positive expectations could indeed have the opposite effect, a reduction in perceived pain and faster recovery.
Finally, the research may help explain why, in some patients, chronic pain may persist long after the damaged tissue has healed.
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