Generating gamma waves during Bhramari Pranayama

Report in Consciousness and Cognition [2009 Dec;18(4):977-88] from researchers at the RIKEN Brain Science Institute, Laboratory for Advanced Brain Signal Processing in Japan, announces that "a specific form of yoga can generate controlled high-frequency gamma waves. For the first time, paroxysmal gamma waves (PGW) were observed in eight subjects practicing a yoga technique of breathing control called Bhramari Pranayama (BhPr) . . . . This unusual activity is discussed in relation to previous reports on yoga and meditation. It is concluded this EEG activity is most probably non-epileptic, and that applying the same methodology to other meditation recordings might yield an improved understanding of the neurocorrelates of meditation."  Abstract: PubMed.