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Scenes of Inner Taksang, temple hall, built just above the cave where Padmasambhava meditated

The health applications and clinical studies of meditation are products of the field of interest within the medical community to study the physiological effects of meditation.^[1][2][3][4]

Meditation has entered the mainstream of health care as a method of stress and pain reduction. As a method of stress reduction, meditation has been used in hospitals in cases of chronic or terminal illness to reduce complications associated with increased stress that include depressed immune systems. There is growing agreement in the medical community that mental factors such as stress significantly contribute to a lack of physical health, and there is a growing movement in mainstream science to fund research in this area. There are now several mainstream health care programs which aid those, both sick and healthy, in promoting their inner well-being, especially those mindfulness based programs.

There has been a dramatic increase in the past 10 or 15 years or so of studies on the impact of meditation upon one's health.^[5]

Other studies within this field include the research of Jon Kabat-Zinn and his colleagues at the University of Massachusetts who have studied the effects of mindfulness meditation on stress.^[6][7]

[edit] Mindfulness-based stress reduction

A 2003 meta-analysis found that mindfulness-based stress reduction, which involves continuous awareness of consciousness, without seeking to censor thoughts, concluded that the form of meditation may be broadly useful for individuals attempting to cope with clinical and nonclinical problems. Diagnoses for which MBSR was found to be helpful included chronic pain, fibromyalgia, cancer patients and coronary artery disease. Improvements were noted for both physical and mental health measures.^[8]

[edit] Flow

Mindfulness meditation, anapanasati, and related techniques, are intended to train attention for the sake of provoking insight. A wider, more flexible attention span makes it easier to be aware of a situation, easier to be objective in emotionally or morally difficult situations, and easier to achieve a state of responsive, creative awareness or "flow".^[9]

[edit] Meditation and stress

[edit] National Institute of Health

According to the National Institute of Health (NIH), "Practicing meditation has been shown to induce some changes in the body...Some types of meditation might work by affecting the autonomic (involuntary) nervous system." The sympathetic nervous system and parasympathetic nervous system are two divisions of the autonomic nervous system of the body. The sympathetic nervous system is responsible for our reaction to stress or fear and is colloquially known as the "flight-or-flight" system. The parasympathetic nervous system is active during times of rest and associated with "rest and digest". The NIH goes on, "It is thought that some types of meditation might work by reducing activity in the sympathetic nervous system and increasing activity in the parasympathetic nervous system."

[edit] Goleman: Amygdala and pre-frontal cortex

One theory, presented by Daniel Goleman & Tara Bennett-Goleman^[10] suggests that meditation^{[clarification needed]} works because of the relationship between the amygdala and the prefrontal cortex.^[11] In very simple terms, the amygdala is the part of the brain that decides if we should get angry or anxious (among other things), and the pre-frontal cortex is the part that makes us stop and think about things (it is also known as the inhibitory centre).

The prefrontal cortex is very good at analyzing and planning, but it takes a long time to make decisions. The amygdala, on the other hand, is simpler (and older ^[12] in evolutionary terms). It makes rapid judgments about a situation and has a powerful effect on our emotions and behaviour, linked to survival needs. For example, if a human sees a lion leaping out at them, the amygdala will trigger a fight or flight response long before the prefrontal cortex responds.

But in making snap judgments, our amygdalas are prone to error^{[citation needed]}, such as seeing danger where there is none.^{[citation needed]} This is particularly true in contemporary society where social conflicts are far more common than encounters with predators, and a basically harmless but emotionally charged situation can trigger uncontrollable fear or anger ' leading to conflict, anxiety, and stress.^[13]

[edit] Grey and White Matter

Studies done by Yale, Harvard, Massachusetts General Hospital have shown that meditation increases gray matter in the brain and slows down the deterioration of the brain as a part of the natural aging process.

The experiment included 20 individuals with intensive Buddhist "insight meditation" training and 15 who did not meditate. The brain scan revealed that those who meditated have an increased thickness of gray matter in parts of the brain that are responsible for attention and processing sensory input. The increase in thickness ranged between .004 and .008 inches (3.175 x 10^'6m - 6.35 x 10 ^'6m) and was proportional to the amount of meditation. The study also showed that meditation helps slow down brain deterioration due to aging.^[14][15]

A study involving the participation of a group of colleges students, who were asked to use a meditation technique called integrative body-mind training, concluded that "meditating may improve the integrity and efficiency of certain connections in the brain" through an increase in their number and robustness^[16] Brain scans showed strong white matter changes in the anterior cingulate cortex.^[17]

Dr. James Austin, a neurophysiologist at the University of Colorado, reported that meditation in Zen "rewires the circuitry" of the brain in his book Zen and the Brain (Austin, 1999). This has been confirmed using functional MRI imaging, a brain scanning technique that measures blood flow in the brain.^{[citation needed]}

[edit] Theoria

Fifteen Carmelite nuns came from the monastery to the laboratory to enter a huge fMRI machine whilst meditating, allowing scientists there to scan their brains using fMRI while they were in a state known as Unio Mystica (and also Theoria).^[18] The results showed that far-flung parts of the brain were recruited in the sustaining of this mystical union with God.

[edit] Meditation and EEG

Electroencephalograph (EEG) recordings of skilled meditators showed a significant rise in gamma wave activity in the 80 to 120 Hz range during meditation. There was also a rise in the range of 25 to 42 Hz. These meditators had 10 to 40 years of training in Buddhist-based mental^{[clarification needed]} training. EEG done on meditators who had received recent training demonstrated considerably less rise.^[19]

The experienced meditators also showed increased gamma activity while at rest and not meditating.^[19]

During meditation there is a modest increase in slow alpha or theta wave EEG activity.^[19][20]

Chang and Lo found different results, explicable perhaps by the fact they show no sign of even having tested for gamma.^[21] First they classify five patterns in meditation based on the normal four frequency ranges (delta < 4 Hz, theta 4 to <8Hz, alpha 8 to 13 Hz, and beta >13Hz). The five patterns they found were:

1) delta

2) delta + theta

3) theta + slow alpha

4) high-amplitude alpha

5) amplitude suppressed ("silent and almost flat")

They found pattern #5 unique and characterized by:

1) extremely low power (significant suppression of EEG amplitude)

2) corresponding temporal patterns with no particular EEG rhythm

3) no dominating peak in the spectral distribution

They had collected EEG patterns from more than 50 meditators over the prior five years. Five meditation EEG scenarios are then described. They further state that most meditation is dominated by alpha waves. They found delta and theta waves occurred occasionally, sometimes while people fell asleep and sometimes not. In particular they found the amplitude suppressed pattern correlated with "the feeling of blessings."

O Nuallain,Sean (2009) ^[22] in Cognitive Sciences 4(2), is the first to interrelate the work on synchronized gamma in consciousness with the well-attested work on gamma in meditation in an experimental context. It adduces experimental and simulated data to show that what both have in common is the ability to put the brain into a state in which it is maximally sensitive and consumes power at a lower (or even zero) rate, briefly. It is argued that this may correspond to a 'selfless' state and the more typical non-zero state, in which gamma is not so prominent, corresponds to a state of empirical self. Thus, the 'zero power' in the title refers not only to the power spectrum of the brain as measured by the Hilbert transform, but also to a psychological state of personal renunciation.

[edit] Meditation and Perception

Studies have shown that meditation has both short-term and long-term effects on various perceptual faculties.

In 1984, Brown et al. conducted a study that measured the absolute threshold of perception for light stimulus duration in practitioners and non-practitioners of mindfulness meditation. The results showed that meditators have a significantly lower detection threshold for light stimuli of short duration.^[23]

In 2000, Tloczynski et al. studied the perception of visual illusions (the Müller-Lyer Illusion and the Poggendorff Illusion) by zen masters, novice meditators, and non-meditators. There were no statistically significant effects found for the Müller-Lyer illusion, however, there were for the Poggendorff. The zen masters experienced a statistically significant reduction in initial illusion (measured as error in millimeters) and a lower decrement in illusion for subsequent trials.^[24]

The theory of mechanism behind the changes in perception that accompany mindfulness meditation is described thus by Tloczynski:

'A person who meditates consequently perceives objects more as directly experienced stimuli and less as concepts' With the removal or minimization of cognitive stimuli and generally increasing awareness, meditation can therefore influence both the quality (accuracy) and quantity (detection) of perception.'^{[cite this quote]}

Brown also points to this as a possible explanation of the phenomenon: '[the higher rate of detection of single light flashes] involves quieting some of the higher mental processes which normally obstruct the perception of subtle events.' In other words, the practice may temporarily or permanently alter some of the top-down processing involved in filtering subtle events usually deemed noise by the perceptual filters.

[edit] The Relaxation Response

Dr. Herbert Benson of the Mind-Body Medical Institute, which is affiliated with Harvard University and several Boston hospitals, reports that meditation induces a host of biochemical and physical changes in the body collectively referred to as the "relaxation response."^[25] The relaxation response includes changes in metabolism, heart rate, respiration, blood pressure and brain chemistry. Benson and his team have also done clinical studies at Buddhist monasteries in the Himalayan Mountains.^{[citation needed]}

[edit] Adverse effects

The following is an official statement from the government-run National Institute of Health (NIH) available on this webpage of theirs,

Meditation is considered to be safe for healthy people. There have been rare reports that meditation could cause or worsen symptoms in people who have certain psychiatric problems, but this question has not been fully researched. People with physical limitations may not be able to participate in certain meditative practices involving physical movement. Individuals with existing mental or physical health conditions should speak with their health care providers prior to starting a meditative practice and make their meditation instructor aware of their condition.^[26]

Both positive rewards and potential benefits of meditation have been noted in academic literature. Adverse effects have been reported,^[27] and may, in some cases, be the result of "improper use of meditation" ^[28]. The NIH advises, among other things, on this webpage, to, "Ask about the training and experience of the meditation instructor you are considering."^[26]

See Kundalini syndrome for more on the topic of a potential, and debated, adverse effect from practicing Kundalini Yoga.

Drugs have a long history of use amongst many religious ways of life. The ingestion of certain psychoactive drugs is considered by many to be harmful to the human body. See Entheogens and Religion and drugs for more information on this topic.

As with any practice, meditation may also be used to avoid facing ongoing problems or emerging crises in the meditator's life. In such situations, it may be helpful to apply mindful attitudes acquired in meditation while actively engaging with current problems.^[29] According to the NIH, meditation should not be used as a replacement for conventional health care or as a reason to postpone seeing a doctor.^[26]

[edit] Unreasonable health claims

At different times, some researchers have made extraordinary claims in favor of meditation. For one, a 1972 study claimed that Transcendental Meditation affected the human metabolism by lowering the biochemical byproducts of stress, such as lactate, decreasing heart rate and blood pressure and inducing favorable brain waves.^[30]

In 1976, the Australian psychiatrist Ainslie Meares reported the spontaneous regression of a single case of rectal cancer following intensive meditation. After writing about this uncontrolled case study involving a cancer known for occasional spontaneous regressions,^[31] Meares would go on to write a number of books, including his best-seller Relief Without Drugs.^[32]

[edit] State of the research

A comparison of the effect of various meditation techniques on systolic blood pressure.^[33]

In June, 2007 the United States National Center for Complementary and Alternative Medicine (NCCAM) published an independent, peer-reviewed, meta-analysis of the state of meditation research, conducted by researchers at the University of Alberta Evidence-based Practice Center. The report reviewed 813 studies involving five broad categories of meditation: mantra meditation, mindfulness meditation, yoga, Tai Chi, and Qi Gong, and included all studies on adults through September 2005, with a particular focus on research pertaining to hypertension, cardiovascular disease, and substance abuse.

The report concluded, "Scientific research on meditation practices does not appear to have a common theoretical perspective and is characterized by poor methodological quality. Firm conclusions on the effects of meditation practices in healthcare cannot be drawn based on the available evidence. Future research on meditation practices must be more rigorous in the design and execution of studies and in the analysis and reporting of results." (p. 6) It noted that there is no theoretical explanation of health effects from meditation common to all meditation techniques.^[34]

A further analysis of this data set in 2008 reaffirmed the weaknesses of the research, finding that "Most clinical trials on meditation practices are generally characterized by poor methodological quality with significant threats to validity in every major quality domain assessed". This was the conclusion despite a statistically significant increase in quality of all reviewed meditation research, in general, over time between 1956-2005. Of the 400 clinical studies, 10% were found to be good quality. A call was made for rigorous study of meditation.^[35] These authors also noted that this finding is not unique to the area of meditation research and that the quality of reporting is a frequent problem in other areas of complementary and alternative medicine (CAM) research and related therapy research domains.

In 2006 NCCAM revised their definition of meditation, emphasizing the experience of the 'suspension of thought activity". This definition led to the possibility of comparing mental silence oriented meditation with resting alone and one study found significant physiological differences between the two.^[36]

[edit] See also

• Research studies on the applications of Transcendental Meditation
• Buddhist meditation
• Meditation

[edit] References

[edit] External links

• Meditation Practices for Health: State of the Research Agency for Healthcare Research and Quality