A surprising event, created by the sudden disappearance of a visual threat combined with delayed harmful heat, amplifies the intensity of the pain.
- Your brain amplifies pain when it occurs by surprise due to the gap between what you plan and what you feel.
- Thus, the feeling of control influences the intensity of pain.
- This discovery could open the way to new therapies for chronic pain which focuses on management of expectations and reducing uncertainty.
The perception of pain can vary considerably. Indeed, it happens that you feel more intense than expected as a result of an injury or due to a physical illness, but that you feel less intense pain in other similar cases. This is explained by the fact that the perception of pain is not only determined by harmful stimuli, but strongly depends on your expectations and your uncertainty.
Volunteers were subject to pain during an experience in virtual reality
“A largely accepted theory suggests that the brain integrates the prediction of pain in harmful stimuli, in order to estimate the intensity of pain. This theory supposes that the estimated value of pain is adjusted to minimize surprise, mathematically defined as the error between predictions and results. However, it is not always known if the surprise represented directly influences the perception of pain estimate”, have indicated researchers from the University of Tsukuba (Japan).
This is why, as part of a study, the latter looked at this question empirically using virtual reality. In experience, healthy participants received painful thermal stimuli in their arms. They reported the intensity of the pain felt while observing painful or non -painful visual stimuli in virtual reality. “To manipulate the level of surprise, the visual threat suddenly disappeared randomly, and the harmful heat was presented in the action or post-action phases.”
The brain more strongly perceives pain that it has not anticipated
According to the results, published in the journal Cognitionthe volunteers strongly perceived the pain when the prediction error was important, which demonstrates that the hypothesis of surprise explains the mechanism of pain perception better in the brain. The authors also found that pain was amplified when unexpected events occurred.
People with chronic pain often experience waves fears and pain -related anxieties. According to the team, it is possible that this uncertain gap between expectations and reality further increases the perceived intensity of pain. Consequently, the reduction in the gap between expectations and the reality of pain, or “surprise”, is important to reduce pain. A better understanding of the perception of pain would facilitate the development of new treatments that would improve the healing of chronic pain and trauma.
