In three pre-registered experiments, Bar-Ilan University researchers found that directing attention to itching and burning after exposure to histamine was associated with a smaller and shorter local inflammatory response; the finding is not evidence for the treatment of chronic inflammation.
The instinct when something itches, burns, or hurts is often to distract yourself. New research fromBar-Ilan University found a surprising result in the opposite direction: when participants were asked to turn theattention to the sensations created after local exposure toHistamine, the response ofinflammation The skin was smaller than when they were distracted.
The study, published in Nature Human Behaviour, involved three pre-planned and pre-registered experiments involving a total of 57 healthy participants. The researchers used a skin prick test with histamine, which produces a local, brief, measurable response of swelling and redness.
Same stimulus, different direction of attention
In the experimental design, each participant essentially served as his own control. In one condition, he was asked to focus on the itching or burning sensation in the area where the histamine was administered. In another condition, he was instructed to distract himself from the sensation.
In the first two samples, about 90% of participants showed a greater inflammatory response in the distraction condition. After 20 minutes, the average diameter of the swelling was about 3.5 millimeters in the internal attention condition compared to about 5 millimeters in the distraction condition. The area of redness was also smaller: about 10.6 versus 14 millimeters in the measurement used by the researchers.
The difference began to appear within a few minutes, and the response in the internal attention condition faded more quickly.
Listening did not necessarily reduce the feeling
The finding is important precisely because the effect of attention on inflammation is not equivalent to simply “feeling better.” Paying attention to the itching or burning can increase awareness of the sensation, yet the physiological measure of local inflammation was smaller.
Therefore, the research is not only about how we interpret pain or itching, but also about whether top-down attentional control can influence a person's response. immune system In the periphery.
What happened when they weakened sensory input?
In another experiment, the researchers used topical lidocaine to reduce sensory input from the skin. The intervention weakened the difference between the two attentional states but did not completely eliminate it.
The result supports the possibility that the link between attention and inflammation has a component that depends on sensory information coming from the skin, but probably not only on it. The researchers also examined heart rate variability, an indirect measure of parasympathetic system activity, and found higher values during internal attention.
One possibility is the involvement of neural pathways that connect the brain, the autonomic system, and the immune system, including pathways related toעצב הוואגוסHowever, heart rate variability is not a direct measurement of vagal activity, so the study does not prove that this nerve is the causal mechanism.
Not a prescription for "thought therapy"
It is important to set a clear boundary for interpretation here. The participants were healthy people, and the researchers measured an acute, local response to histamine. There is no evidence yet that mindfulness can treat chronic inflammation, autoimmune disease, infection, or any other medical condition.
Nor have all the molecular mediators that link the nervous system to the skin response been directly measured. The study shows a controlled experimental relationship between an attentional state and the intensity of a particular inflammatory response; it does not prove that one can "think inflammation out."
The scientific importance of the finding is that it adds evidence that cognitive processes can rapidly influence bodily systems that are typically considered automatic. The next step will be to determine which neural and immune pathways mediate the effect, and to what extent it also holds true in real medical conditions.
Questions and Answers
Should you focus on pain or itching to reduce inflammation?
Not yet a medical recommendation. The study examined an acute, controlled skin reaction to histamine in healthy people, not inflammatory diseases or chronic pain.
Does the study prove that the vagus nerve is responsible for the effect?
No. Changes were found in an index related to parasympathetic activity, but this is an indirect index. Further studies are needed to identify the causal pathway.
Is this a placebo effect?
Not in the usual sense of giving a sham treatment. The participants received the same physiological stimulus, and the variable being tested was the direction of attention. However, the study is part of the broader question of how brain processes affect the body.
Can we conclude anything about chronic inflammation from this?
Not at this stage. Chronic inflammation is much more than a local, short-term response to histamine, so dedicated studies are needed.
The scientific article
More on the subject on the science website
- The brain's reward system can influence the immune response
- Placebo 3 - the study of the phenomenon
- Brain-liver axis and the vagus nerve
- Mitochondria as a factor in controlling the immune system and inflammation
For the scientific article: Opening the scientific article
