Health applications and clinical studies of meditation

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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]

Many concepts of meditation have been applied to clinical settings in order to measure its effect on somatic motor function as well as cardiovascular and respiratory function. Also the hermeneutic and phenomenological aspects of meditation are areas of growing interest. Meditation has entered the mainstream of health care as a method of stress and pain reduction. For example, in an early study in 1972, Transcendental Meditation was shown to affect the human metabolism by lowering the biochemical byproducts of stress, such as lactate, decreasing heart rate and blood pressure and inducing favorable brain waves.^[2] In 1976, the Australian psychiatrist Ainslie Meares reported the regression of cancer following intensive meditation (published in the Medical Journal of Australia). Meares would go on to write a number of books, including his best-seller Relief Without Drugs.

As a method of stress reduction, meditation is often used in hospitals in cases of chronic or terminal illness to reduce complications associated with increased stress including a depressed immune system. 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. 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.

Dr. Herbert Benson of the Mind-Body Medical Institute, which is affiliated with Harvard 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."^[3] 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.

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.^[4]

Contents 1 Meditation and the brain 2 Meditation and EEG 3 Meditation and Perception 4 Adverse effects 5 Meditation and drugs 6 See also 7 References

[edit] Meditation and the brain

Mindfulness meditation 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".^[5]

One theory, presented by Daniel Goleman & Tara Bennett-Goleman (2001), suggests that meditation works because of the relationship between the amygdala and the prefrontal cortex.^[6] 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).

So, 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 ^[7] 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^[8], such as seeing danger where there is none. 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.^[9]

Because there is a gap^[10] between the time an event occurs and the time it takes the amygdala to react, a skilled meditator may be able to intervene before a fight or flight response takes over, and perhaps even redirect it into more constructive or positive feelings.^[11]

Studies done by Yale, Harvard, Massachusetts General Hospital have shown that meditation increases gray matter in the brain and slows down certain brain deterioration. 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 thickness increased was not much. It only increased from eight thousandths of an inch to four thousandths of an inch (3.175 x 10^-6m - 6.35 x 10 ^-6m). The amount of meditation is directly proportional to the increase in gray matter. The study also show that meditation helps slow down brain deterioration due to aging. ^[12][13]

[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 training. EEG done on meditators who had received recent training demonstrated considerably less rise.^[14]

The experienced meditators also showed increased gamma activity while at rest and not meditating.^[14]

During meditation there is a modest increase in slow alpha or theta wave EEG activity.^[14][15]

Chang and Lo found different results.^[16] First they classify five patterns in meditation based on the normal four frequency ranges (delta < 4Hz, theta 4 to <8Hz, alpha 8 to 13Hz, 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."

[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.^[17]

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 Muler-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.^[18]

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.”

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] Adverse effects

Predominantly, studies of meditation report positive effects. However, some studies report that meditation may have adverse effects in certain circumstances.^[19][20] If practiced improperly or too intensely, meditation can lead to considerable psychological and physiological problems. Serious and credible teachers of meditation usually warn their students about the possible pitfalls of a contemplative path.^[21]

Another issue concerns the adaptation of eastern meditative concepts to a western culture, an adaptation that is often unfamiliar with the cultural matrix in which the meditative concept originated. Eastern concepts of meditation are often imported to a western setting within the popular context of new religious movements, or within the context of popular approaches to body and health. It is common for this popular context to be unfamiliar with the broad range of adverse effects that might occur during meditation, and to have limited tools for dealing with them when they do arise. Since the practice of meditation may include a powerful confrontation with existential questions, it is not considered wise to engage in intense meditation techniques without an extended period of psychological preparation, preferably in contact with a credible teacher or clinician. In the case of Asian contemplative traditions (Hindu, Buddhist), which has often originated within a monastic or reclusive context, there often exist major challenges connected to the way the particular meditation techniques are to be applied to a Western mindset without causing harm to the practitioner, for example passivity.

A growing body of clinical literature is now starting to address the phenomenon of meditation-related problems.^[19][20] Several side-effects have been reported, including uncomfortable kinesthetic sensations, mild dissociation and psychosis-like symptoms.^[22] From a clinical study of twenty-seven long term meditators, Shapiro (1992) reported such adverse effects as depression, relaxation-induced anxiety and panic, paradoxical increases in tension, impaired reality testing, confusion, disorientation and feeling 'spaced out'. The possibility that meditation might trigger strong emotional reactions is also reported by Kutz, Borysenko & Benson (1985). Therefore, meditation might cause serious side effects, even among long-term practitioners, and might even, in some instances, be contraindicated. The tendency of meditation to release unconscious material implies that the beginning meditator should approach the practice with moderation.^[20]

Particularly in the Chinese Qigong tradition, stories of unguided practitioners or inexpertly guided students developing chronic mental and physical health problems as a result of their attempts at meditation training are not uncommon. English speaking practitioners and teachers of Qigong and related disciplines note that the practice of this contemplative exercise is sometimes accompanied by physical and psychological distress. The identification of this syndrome has led to the inclusion of a culture-sensitive category in the DSM-IV called Qi-Gong Psychotic Reaction.^[23]

Meditative traditions which include the use of drugs are by some considered to be harmful to the practitioner. Additionally, 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.^[24]

[edit] Meditation and drugs

Some modern methods of meditation disallow the use of drugs due to the known associated health problems. However, the use of stimulants has been proposed by some as a means to provide insight, and in some shamanistic traditions they are used as agents of ritual. Some Native American traditions emphasized the smoking of a pipe containing tobacco, salvia divinorum or other plants. East Asian traditions use tea and Middle Eastern (and many Western) religions use coffee as an aid to meditation.

During the 1960s, eastern meditation traditions and psychedelics such as LSD became popular, and it was suggested that LSD use and meditation were both means to the same spiritual/existential end. Many practictioners of eastern traditions rejected this idea, including many who had tried LSD themselves. In The Master Game, de Ropp said that the door to full consciousness could be glimpsed through with the aid of substances -- which is doubted by many others -- yet to pass beyond the door required yoga and meditation. In the case of Transcendental Meditation, the use of these so-called recreational drugs is strongly discouraged, and a two-week abstinence from them prior to learning the technique is required of any beginner.^[25] Other authors, such as Rick Strassman, believe that the relationship between religious experiences reached by way of meditation and through the use of psychedelic drugs deserves further exploration.^[26]

[edit] See also

• Buddhism and psychology

[edit] References