Increased Gamma Brainwave Amplitude Compared to Control in Three Different Meditation Traditions

Despite decades of research, effects of different types of meditation on electroencephalographic (EEG) activity are still being defined. We compared practitioners of three different
meditation traditions (Vipassana, Himalayan Yoga and Isha Shoonya) with a control group
during a meditative and instructed mind-wandering (IMW) block. All meditators showed
higher parieto-occipital 60–110 Hz gamma amplitude than control subjects as a trait effect
observed during meditation and when considering meditation and IMW periods together.
Moreover, this gamma power was positively correlated with participants meditation experience. Independent component analysis was used to show that gamma activity did not originate in eye or muscle artifacts. In addition, we observed higher 7–11 Hz alpha activity in the
Vipassana group compared to all the other groups during both meditation and instructed
mind wandering and lower 10–11 Hz activity in the Himalayan yoga group during meditation
only. We showed that meditation practice is correlated to changes in the EEG gamma frequency range that are common to a variety of meditation practices.