While much of the research on meditation and the brain involves Buddhist or TM practitioners in only one state of meditation, Theravada Buddhists meditators practicing the "eight jhanas" provided a group of neural researchers (Hagerty, Isaacs, Brasington, Shupe and Fetz) the opportunity to observe a trained Theravadan contemplative in varying states of meditation, utilizing the jhanas as benchmarks and the opportunity to use the resting state of the meditator himself as a control group.
Meditation on the "eight jhanas," while prominent in the Buddha's time, is now largely restricted to the Theravadan tradition centered in Sri Lanka and Southeast Asia. The contemplative states reached by meditators in the different levels of the jhanas are variously described by the researchers as follows:
"The first jhana is described as intense physical energy and emotional joy, often accompanied by muscle tension, twitching, tears, hair standing on end, etc. The second jhana is more sedate, with physical relaxation, a strong sense of joy coming in waves and only a minor sense of physical energy. The third jhana is energetically quiet, but with strong contentment and happiness. In the fourth jhana the pleasure turns to neutrality, described as equanimity."Put together, the "eight jhana" meditation sounds like an ascent to nirvana, as do the powerful changes the meditation seems to effect in the brains of the contemplatives - at least based on these results.
"In the fifth jhana one senses an infinite space all around. In the sixth jhana one senses that one’s consciousness has become infinite. In the seventh jhana there is a deep sense of nothingness, an absence of form. The eighth jhana is named “neither perception nor non-perception” because the mind does not even categorize the experience."
Utilizing an EEG connected to the scalp to monitor the contemplative's brain wave functions, the researchers were able to follow the contemplative's sequential ascent through the eight different stages of this focused meditation, and his subsequent descent. And the results, while technical, were impressive.
The data confirmed the researchers' predictions in four of the five categories with mind 'chatter' and external awareness dimming and the sense of personal boundaries expanding. Yet while, the subject's attention was indeed shown to become highly focused, only some of his "shoulds" diminished. One wonders how the subject would have done were he not required to communicate with the researchers via a clicking a mouse as he passed through the phases and peak phases of the jhana meditation. But I guess that, alas, even such a well-designed experiment could not wholly eliminate all the "shoulds" that we each encounter everyday. Thank goodness that in our own meditations we don't have to deal with such distractions, we just need to sit.
For those who remain skeptical of the ability of meditation to change the internal state of a skilled contemplative, check out the video, below, as polymath philosopher/spiritual pandit, best-selling author and meditator, Ken Wilber stops his brainwaves during a progressive meditation.