Giandomenico Iannettija from the part of Physiology said that in everyday life, we are mostly using the left hand to touch the items on the left and right for the items on the right. In his words, brain areas that contained a map of the right body and right of the map outside world usually are activated together, resulting in effective treatment of pain.
When you cross your hand, these maps are no longer activated together, and that leads to reducing efficiency of brain processing of sensory stimuli, including pain.
The scientists used a laser in a study and on a hand of eight participants in the study generated the sting of four milliseconds. This is the so-called clean pain inflicted without touching.
The process is then repeated, and participants had crossed hands. The results showed that the perception of pain is milder if the hands are crossed. Iannetti also said that maybe we, when we are in pain had to cross our arms in order to feel less pain.
The researchers hope that their discovery could help in developing new drugs and therapies to reduce pain, which would be based on brain maps of the body.