Researchers from Massachusetts General Hospital (MGH), the Osher Research Center at Harvard Medical School and the Massachusetts Institute of Technology have found that positive effects of mindfulness meditation on pain and working memory may result from an improved ability to regulate alpha rhythms to deal with an often-overstimulating world.

Previous studies have suggested that attention can be used to regulate alpha rhythms and, in turn, sensory perception. When an individual anticipates a touch, sight or sound, the focusing of attention toward the expected stimulus induces a lower alpha wave height in cortical cells that would handle the expected sensation, which actually “turns up the volume” of those cells. At the same time the height of the alpha wave in cells that would handle irrelevant or distracting information increases, turning the volume in those regions down.

Because mindfulness meditation — in which practitioners direct nonjudgmental attention to their sensations, feelings and state of mind — has been associated with improved performance on attention-based tasks, the research team decided to investigate whether individuals trained in the practice also exhibited enhanced regulation of the timing and intensity of alpha rhythms.

The study tested 12 healthy volunteers with no previous experience in meditation. Half completed the eight-week Mindfulness-Based Stress Reduction Program developed at the University of Massachusetts. The other half were asked not to engage in any type of meditation during the study period. Using magnetoencephalography (MEG), an imaging technique that detects the location of brain activity with extreme precision, the researchers measured participants’ alpha rhythms before, during and after the eight-week period.

The researchers measured alpha rhythms in the brain area that processes signals from the left hand while participants were asked to direct their attention to either their left hand or left foot. Participants’ abilities to adjust the alpha rhythm in cortical cells associated with the hand, depending on where their attention was directed, were recorded during the milliseconds immediately after they received an attention cue.

Although all participants had showed some attention-related alpha rhythm changes at the beginning of the study, at the end of the eight weeks, those who completed the mindfulness meditation training made faster and significantly more pronounced attention-based adjustments to the alpha rhythm than the non-meditators did. “This result may explain reports that mindfulness meditation decreases pain perception,” says Catherine Kerr, PhD, of the Martinos Center for Biomedical Imaging at MGH and the Osher Research Center at Harvard Medical School, co-lead author of the report. “Enhanced ability to turn the alpha rhythm up or down could give practitioners’ greater ability to regulate pain sensation.”

The implications extend far beyond meditation and provide clues about possible ways to help people better regulate a brain rhythm that is dysregulated in attention-deficit hyperactivity disorder and other conditions, says Stephanie Jones, PhD, of the Martinos Center, co-lead author of the paper..

Ref.: Catherine E. Kerr et al., Effects of mindfulness meditation training on anticipatory alpha modulation in primary somatosensory cortex, April 8 online edition, Brain Research Bulletin

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