Scientists today perform a significant amount of formal research on various meditation techniques. Because the word 'meditation' is used loosely in society to describe many different activities, scientists have to be careful about how they use the term in context of research.
Dr. Fred Travis of Maharishi University of Management has been promoting a unified set of terms to categorize the many meditation techniques which exist today. In fact, he argues that all forms of meditation can be narrowed down to three types. These types are defined based on the techniques used, and these techniques correlate clearly to very specific, and distinguishable neurological responses.
To summarize, Dr. Travis encourages all researchers to utilize these three terms to describe the kind of meditation they use in their studies.
Travis, F. and Shear, J. (2010). Focused attention, open monitoring and automatic self-transcending: Categories to organize meditations from Vedic, Buddhist and Chinese traditions. Consciousness and Cognition, 19:1110-1119.
For detailed information about the terminology, please refer to the paper above. All quotes in this article come from the study above.
Please note that within these broad categories, there are of course variations which are worthy of detailed study. However, in the literature, Travis and Shear argue that having these larger containers will help researchers create comparisons between different techniques, and draw more general conclusions about the forms themselves.
1. Focused Attention
Focused attention techniques are the stereotypical 'focus your thoughts, empty your mind' techniques. These vary from starting into a single point, to counting up in numbers mentally without allowing the mind to stray. While the techniques vary, the overall effect on the brain is surprisingly similar. Focused attention meditations result in beta2 and gamma activity.
"In focused attention or concentrative style of meditations, voluntary sustained attention is focused on a given object, and attention is brought back to the object of attention when the mind has wandered."
"Beta2 and gamma activity have been reported across meditation practices from the Tibetan Buddhist, Chinese, and Buddhist traditions. Beta2 and gamma activity was reported when individuals sustained focused on an area of the body or when creating a strong inner emotion or a strong visual image, and strictly controlling the deviation of attention from that object."
"Gamma activity reflects local processing within short-range connections responsible for object recognition and so construction of the content of experience (Lubar, 1997; Singer, 1999). Synchronized gamma serves as a gain control for mental processing (Salinas & Sejnowski, 2001), enabling postsynaptic potentials to integrate and so direct downstream networks to bind the elements of sensory processing into a perceptual object (von Stein & Sarnthein, 2000). Gamma band activity closely follows local changes in brain blood flow and increases synaptic plasticity important for long term memories (Niessing et al., 2005)."
"Cortico-thalamic feedback loops modulating attention operate in the beta1 frequency. Beta1 bursts shift the system to an attention state that consequently allows for gamma synchronization and perception (Wrobel, 2000). Beta1 activity arises from “regional” processes that develop between nearby macrocolumns (Lubar, 1997). Beta1 activity has been associated with binding of sensory qualities into a unified perception, such as the integration of visual and auditory information (Hanslmayr et al., 2007; von Stein, Rappelsberger, Sarnthein, & Petsche, 1999; von Stein & Sarnthein, 2000). Increase of temporal and parietal 13-18 Hz beta1 coherence was seen across recognition tasks involving pictures, spoken words and written words. Consequently, beta1 activity during meditation practices may play a role in creating the unity of meditation experiences and could be part of all three categories." (see paper above for complete citations)
Examples of techniques in this category include loving-kindness-compassion, qigong, Zen 3rd ventricle, and Diamond Way Buddhism - but there are many more which would fall into this category as well.
2. Open Monitoring
Open monitoring meditations result in theta activity.
"Open monitoring or mindfulness-based meditations, involve the non-reactive monitoring of the content of ongoing experience, primarily as a means to become reflectively aware of the nature of emotional and cognitive patterns."
"Frontal midline theta, which originates in medial prefrontal and anterior cingulate cortices, is a neural index of monitoring inner processes (Vinogradova, 2001). Frontal midline theta is reported during tasks requiring self-control, internal timing, and assessment of reward (Ishii et al., 1999); during working memory tasks (Sarnthein, Petsche, Rappelsberger, Shaw, & von Stein, 1998); and during tasks requiring memory retention and mental imagery (von Stein & Sarnthein, 2000). Frontal midline theta activity increases a few seconds before a self-initiated hand-movement and reaches a peak immediately after the movement (Tsujimoto, Shimazu, & Isomura, 2006). Theta activity dynamically coordinate central executive circuits during serial subtraction (Mizuhara & Yamaguchi, 2007). Consequently, we expect frontal midline theta in a meditation that involves monitoring ongoing experience without high levels of control and manipulation of the contents of experience."
Examples of open monitoring meditation techniques include Vipassana, Zen meditation, Sahaja Yoga, and Concentrative Qigong. Of course, others would fall into this category as well.
3. Automatic Self-Transcending
Automatic self-transcending techniques result in alpha1 activity.
"Transcending involves automatic settling down of mental activity to a state of quiescence. Since cognitive control increases mental activity, transcending procedures would need to involve minimal cognitive control—said to be automatic or effortless."
Examples of Automatic Self-Transcending techniques include Transcendental Meditation (TM) and Natural Stress Relief (NSR).
Noteworthy is the fact that research has shown that "The automaticity of the TM technique is reflected in research reporting the lack of a novice/expert dichotomy among TM meditators, in contrast to research on other meditation traditions". This means that meditations in this category do not require practice or skill to master. The consciousness simply responds to the technique effectively the first time the technique is initiated in the mind.
"Alpha activity in association areas may represent liveliness of the “screen of consciousness,” which provides context for grouping isolated elements into the unity of experience. For instance, when solving a problem by intuition or insight, alpha activity increases first, followed by increases in the gamma band when the idea comes to mind (Kounios & Beeman, 2009). Also, cross frequency coherence—the synchrony between alpha, beta and gamma—increases with higher cognitive load on a continuous mental arithmetic task. Cross frequency coherence is considered important for integrating anatomically distributed processing in the brain"
What Meditation IS NOT
In many studies on meditation, the control group uses simple eyes-closed rest. Results of this 'technique' are then compared to the real technique. It's a lot like using a placebo when studying a new drug.
The term 'meditation' should not be confused with eyes-closed rest, or simple relaxation techniques.
Researchers can benefit from utilizing these three categories of meditation to describe their studies in a way which is universally understandable. This will help with efforts to understand the differences and similarities between different meditation techniques.