TM considerably increased the the tolerance to stress induced by strong pain
Brain imaging with Magnetoencefalography was used to study the recation of the brain to severe pain before and after learning TM.
Professor Zang Hee Cho, world leading expert on brain imaging participated in this research. He is the invenor of positron emission tomografi (PET), an advanced method for investigating the brain.
Professor Cho speculated in the possibility that brain imaging should show changes if TM has a significant effect on stress tolerance as indicated by several other studies for example on air force pilots. Cho, reasoned that this should appear as decreased activtion of the brain stress centers in stress situation.
Cho recommended Magnetoencephalography in this case because this technique is simpler and cheapr that his own PET-scan-method, and yet it gives essentilally the same information in this case.
To elicity stress, strong pain, was used becaue it is well known to be an effective "stressor". The pain was elicited by dipping the hands in so hot water that it was hardly bearaable.
After 5 months of TM the stressreaction in the brain decreased by 50% compared to controls. See the diagram below.
Figuren: The diagram shows computer-generated "slices " of one and the same brain seen from the sida. The more of orange color, the more excited is the brain tissue. Compare the pictures at right and left "slice by slice" and you will see how greatly the excitation of the brain was decreased after 5 months. At an average the decrease was 40-50%.
The subjects were asked both before learning TM and at the second test after 5 months how painful it was by using a 9-grade (stanine) scale. In both cases the experience was maximum pain (9).
Orme-Johnson, D. W., Schneider, R. H., Son, Y. D., Nidich, S., Cho, Z-H. Neuroimaging of Meditation's Effect on Brain Reactivity to Pain. NeuroReport, August 23, 2006.
This is a very concrete piece of evidence, confirming other research indicating that TM considerably increases stress tolerance.
A study from a completely different angle of approach indicated increased stress tolerance in Air Force pilots using a psychological test for combat pilot selection.