Researchers from the State Research Institute of Physiology at the Russian Academy of Medical Sciences in Novosibirsk, Russia, mounted a controlled, randomized clinical trial to examine how long-term meditation practice can effect EEG activity during non-emotional arousal (eyes-closed and eyes-open periods, viewing emotionally neutral movie clip) and while experiencing experimentally induced negative emotions (viewing an aversive movie clip).
The 62-channel EEG was recorded in age-matched controls (n=25) and for Sahaja Yoga meditators (SYM, n=25). Findings from the non-emotional continuum show that, at the lowest level of arousal (eyes closed), SYM manifested larger power values in theta-1 (4-6 Hz), theta-2 (6-8 Hz) and alpha-1 (8-10 Hz) frequency bands. Although increasing arousal desynchronized activity in these bands in both groups, the theta-2 and alpha-1 power in the eyes-open period and alpha-1 power while viewing the neutral clip remained still higher in the SYM. During eyes-closed and eyes-open periods the controls were marked by larger right than left hemisphere power, indexing a relatively more active left hemisphere parieto-temporal cortex, whereas the meditators showed asymmetry between hemispheres.
When contrasted with the neutral condition, the aversive movie clip yielded significant alpha desynchronization in both groups, reflecting the arousing nature of emotional induction. In the control group, along with alpha desynchronization, the affective movie clip synchronized gamma power over anterior cortical sites. This was not seen in the SYM.
Overall, the presented report emphasizes that the revealed changes in electrical brain activity associated with regular meditation practice are dynamical by nature and depend on arousal level. The EEG power findings also provide the first empirical proof of the theoretical assumption that meditators have better capabilities to moderate the intensity of their emotional arousal.
Citation: Aftanas L, Golosheykin S. International Journal of Neuroscience. 2005 Jun;115(6):893-909.Impact of regular meditation practice on EEG activity at rest and during evoked negative emotions. International Journal of Neuroscience. 2005 Jun; 115 (6): pp.893-909. aftanas@iph.ma.nsc.ru
Posted: 11/06/2006
