Scientific and scholarly literature has identified three major categories of meditation techniques, classified according to EEG signature (electroencephalograph) and the type of mental activity or cognitive processing involved:
1. Focused attention techniques are characterized by concentration or controlled focus on an object of meditation. Brain waves recorded during these practices are typically in the gamma frequency, a pattern commonly seen during any highly focused or controlled mental activity. (Lutz A, et al, 2004)
Open monitoring: Theta waves (4-8 Hz)
3. Automatic self-transcending describes meditation practices designed to transcend or go beyond their own mental activity—not engaging the mind in sustained mental or sensory activity, as in controlled focus or open monitoring, but allowing mental activity to subside spontaneously. Whereas concentration and open monitoring techniques require some mental effort (holding attention on its object or maintaining a mental attitude of "mindfulness"), automatic self-transcending allows the mind to effortlessly transcend the meditation process itself. The Transcendental Meditation technique is this type of practice. The category is called ‘automatic’ because the meditator is not involved in any attempt to control or sustain the process. The EEG pattern associated with this approach is frontal alpha coherence, characteristic of reduced mental activity along with relaxed inner wakefulness. (Travis, Arenander, & DuBois, 2004; Travis et al., 2010)
Automatic self-transcending: Frontal alpha1 (8-10 Hz) coherence
What is ‘transcending?’
During the Transcendental Meditation technique, the meditator effortlessly, systematically transcends: the mind spontaneously settles inward, away from the surface, active levels of thinking, enjoying progressively more settled and refined levels of experience—going beyond mental activity entirely to arrive at the silent state of restful alertness or pure consciousness. In this low-stress state, the mind is said to access its inner reserves of intelligence, creativity and order.
Neuroscientists have found that the meditative state experienced during TM practice corresponds to a distinct style of brain activity and range of physiological changes that has not been reported from controlled focus or open monitoring practices—a state characterized by lowered breath rate, decreased cortisol, reduced basal skin conductance, reduced plasma lactate, decreased activation of the sympathetic nervous system and increased EEG coherence. Scientific research shows that the experience of twice-daily transcending through the TM technique reduces anxiety, depression and stress-related disorders, improves cardiovascular health and stimulates growth of creativity and intelligence in daily life.
Because the TM technique is itself non-religious, it does not conflict with religious practices or other kinds of meditation. People involved in other practices, whether religious or non-religious forms of meditation, commonly report that the TM technique helps fulfill the aims of their practice and can be enjoyed as a complementary way to gain deep relaxation, improve focus and clarity, alleviate stress and accelerate personal growth.
Maharishi speaks on the mechanics of meditation:
Is TM the only way to transcend?
• How the TM technique differs from concentration, mindfulness, other mantra practices and everything else