The study used 60 practitioners of transcendental meditation in a double-blind study. The experimental group meditated for 20 minutes while the control group read text. Their concentration was tested before and after the experiment. The study found that meditation had no measurable short-term effects on concentration. Moreover, the subjects that were more experienced in meditation did not have a higher concentration score than subjects who were less experienced.
The study used the same number of males and females. The subjects' experience in transcendental meditation varied from a few days to 99 months. The concentration test called d2 was used for both groups. The tests had subjects cross out 'd's that had two marks around the letter (example of test in picture). They were measured on both speed and accuracy.
The authors acknowledge that the main issue with this study is that the test used to measure concentration, the d2 test, may not be the best way to measure the supposed benefits of transcendental meditation. Even so, the results of this study shows that the claimed benefits of transcendental meditation should be met with skepticism.
Transcendental meditation could still be a useful practice though. As discussed in last week's post about brain training. there is a possible placebo effect with transcendental meditation. Though the study did not show an improvement, it is possible that by believing meditation works while practicing it, the subject's concentration could increase. if this is the case for some, than meditation could have benefits.
I am hesitant to say that the possible placebo effects could still make meditation useful for the intelligence community, as members of the IC tend to be fairly skeptical. which would greatly reduce any placebo effect.
Sabel, B (1980). Transcendental meditation and concentration ability, Perceptual and Motor Skills. 50:3, 799-802. Retrieved from http://www.amsciepub.com/doi/pdf/10.2466/pms.19126.96.36.1999