Research on the processes and effects of meditation

Meditation

Meditation is any form of a family of practices in which practitioners train their minds or self-induce a mode of consciousness to realize some benefit....

 is a growing subfield of neurological research. Modern scientific techniques and instruments, such as fMRI and EEG

EEG

EEG commonly refers to electroencephalography, a measurement of the electrical activity of the brain.EEG may also refer to:* Emperor Entertainment Group, a Hong Kong-based entertainment company...

, are being used to study the body of people who've engaged in meditation in order to determine both how the process of meditation works and also the effects of meditation on the practitioners. Meditation changes the brain

Neuroplasticity

Neuroplasticity is a non-specific neuroscience term referring to the ability of the brain and nervous system in all species to change structurally and functionally as a result of input from the environment. Plasticity occurs on a variety of levels, ranging from cellular changes involved in...

 and the body. These studies have showed substantial bodily changes as a consequence of regular meditative practice, including growth in regions of the brain activated according to the style of meditation. Meditation is similar to learning other skills like how to ride a bike or play an instrument. Through repeated practice meditation leads to an increase in qualities such as love and empathy, ability to pay attention, greater relaxation, and so on.

Methodological concerns have been raised about the studies done on meditation. Since the 1950s nearly 1,000 studies and still very little is known about this field.

Meditation has historically been practiced within religious traditions especially by monks. Today much of what is considered meditation in the West is secular in nature, for instance mindfulness-based programs

Mindfulness (psychology)

Modern clinical psychology and psychiatry since the 1970s have developed a number of therapeutic applications based on the concept of mindfulness in Buddhist meditation.-Definitions:...

. Today mindfulness-based meditative practices have become popular within the wider medical and psychological Western community. For more information see Mindfulness (psychology)

Mindfulness (psychology)

Modern clinical psychology and psychiatry since the 1970s have developed a number of therapeutic applications based on the concept of mindfulness in Buddhist meditation.-Definitions:...

 and Buddhism and psychology

Buddhism and psychology

Buddhism and psychology overlap in theory and in practice. Over the last century, three strands of interplay have evolved:* Descriptive phenomenology: Western and Buddhist scholars have found in Buddhist teachings a detailed introspective phenomenological psychology .* Psychotherapeutic meaning:...

.

Western Therapeutic Use

Meditation has entered the mainstream of health care as a method of stress

Stress (medicine)

Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...

 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

Positive psychology

Positive psychology is a recent branch of psychology whose purpose was summed up in 1998 by Martin Seligman and Mihaly Csikszentmihalyi: "We believe that a psychology of positive human functioning will arise, which achieves a scientific understanding and effective interventions to build thriving in...

, in promoting their inner well-being, especially those mindfulness based programs

Mindfulness (psychology)

Modern clinical psychology and psychiatry since the 1970s have developed a number of therapeutic applications based on the concept of mindfulness in Buddhist meditation.-Definitions:...

.

Mindfulness-based stress reduction

A 2003 meta-analysis

Meta-analysis

In statistics, a meta-analysis combines the results of several studies that address a set of related research hypotheses. In its simplest form, this is normally by identification of a common measure of effect size, for which a weighted average might be the output of a meta-analyses. Here the...

 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

Chronic pain

Chronic pain has several different meanings in medicine. Traditionally, the distinction between acute and chronic pain has relied upon an arbitrary interval of time from onset; the two most commonly used markers being 3 months and 6 months since the initiation of pain, though some theorists and...

, fibromyalgia

Fibromyalgia

Fibromyalgia is a medical disorder characterized by chronic widespread pain and allodynia, a heightened and painful response to pressure. It is an example of a diagnosis of exclusion...

, cancer

Cancer

Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...

 patients and coronary artery disease. Improvements were noted for both physical and mental health measures.

Flow

Mindfulness

Mindfulness (psychology)

Modern clinical psychology and psychiatry since the 1970s have developed a number of therapeutic applications based on the concept of mindfulness in Buddhist meditation.-Definitions:...

 meditation, anapanasati

Anapanasati

Ānāpānasati , meaning 'mindfulness of breathing' , is a form of Buddhist meditation now common to the Tibetan, Zen, Tiantai, and Theravada schools of Buddhism, as well as western-based mindfulness programs.According to tradition, Anapanasati was...

, 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

Flow (psychology)

Flow is the mental state of operation in which a person in an activity is fully immersed in a feeling of energized focus, full involvement, and success in the process of the activity. Proposed by Mihály Csíkszentmihályi, the positive psychology concept has been widely referenced across a variety of...

". Research from Harvard medical school also shows that during meditation, physiological signals show that there is a decrease in respiration and increase in heart rate and blood oxygen saturation levels.

Sympathetic system activation

The human nervous system is composed of a parasympathetic system and a sympathetic system, dealing with relaxation and arousal, respectively. The National Institutes of Health (NIH)

National Institutes of Health

The National Institutes of Health are an agency of the United States Department of Health and Human Services and are the primary agency of the United States government responsible for biomedical and health-related research. Its science and engineering counterpart is the National Science Foundation...

 has written, "It is thought that some types of meditation might work by reducing activity in the sympathetic nervous system

Sympathetic nervous system

The sympathetic nervous system is one of the three parts of the autonomic nervous system, along with the enteric and parasympathetic systems. Its general action is to mobilize the body's nervous system fight-or-flight response...

 and increasing activity in the parasympathetic nervous system

Parasympathetic nervous system

The parasympathetic nervous system is one of the two main divisions of the autonomic nervous system . The ANS is responsible for regulation of internal organs and glands, which occurs unconsciously...

," or equivalently, that meditation produces a reduction in arousal and an increase in relaxation.

Goleman: Amygdala and pre-frontal cortex

One theory, presented by Daniel Goleman

Daniel Goleman

Daniel Jay Goleman is an author, psychologist, and science journalist. For twelve years, he wrote for The New York Times, specializing in psychology and brain sciences. He is the author of more than 10 books on psychology, education, science, and leadership.-Life:Goleman was born in Stockton,...

 & Tara Bennett-Goleman suggests that meditation works because of the relationship between the amygdala

Amygdala

The ' are almond-shaped groups of nuclei located deep within the medial temporal lobes of the brain in complex vertebrates, including humans. Shown in research to perform a primary role in the processing and memory of emotional reactions, the amygdalae are considered part of the limbic system.-...

 and the prefrontal cortex

Prefrontal cortex

The prefrontal cortex is the anterior part of the frontal lobes of the brain, lying in front of the motor and premotor areas.This brain region has been implicated in planning complex cognitive behaviors, personality expression, decision making and moderating correct social behavior...

. 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 amygdala first receives emotional signals and sends them to the prefrontal cortex where planning occurs.

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 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

Lion

The lion is one of the four big cats in the genus Panthera, and a member of the family Felidae. With some males exceeding 250 kg in weight, it is the second-largest living cat after the tiger...

 leaping out at them, the amygdala will trigger a fight or flight

Fight or Flight

Fight or Flight may refer to:* Fight-or-flight response, the biological response of animals to acute stress* "Fight or Flight!" , a song off the album Aneurythm by the American hard rock band Living Syndication...

 response long before the prefrontal cortex responds.

But in making snap judgments, our amygdalas are prone to error because they evolved in times that are so different from our modern ones. Today there are essentially no predators to fight or flee from and yet still the neural circuitry that evolved to deal with them is in place. Today, 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.

The Relaxation Response

Dr. Herbert Benson

Herbert Benson

Herbert Benson, M.D. , is an American cardiologist and founder of the Mind/Body Medical Institute at Massachusetts General Hospital in Boston. He graduated from Wesleyan University and Harvard Medical School....

 of the Mind-Body Medical Institute, which is affiliated with Harvard University

Harvard University

Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...

 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." 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.

Insight meditation

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. Some of the participants meditated for 40 minutes a day while others had been doing it for years. The results showed that the change in brain thickness depended upon the amount of time spent in meditation. The increase in thickness ranged between .004 and .008 inches (3.175 x 10⁻⁶m - 6.35 x 10 ⁻⁶m).

Kundalini Yoga meditation

There have been some preliminary studies done on some of the many types of meditation found within the branch of Yoga known as Kundalini. One study showed the cooling of meditators hands as they did their thing and another study showed some relaxation while meditators payed attention to the breaths.

Grey and White Matter

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 Brain scans showed strong white matter

White matter

White matter is one of the two components of the central nervous system and consists mostly of myelinated axons. White matter tissue of the freshly cut brain appears pinkish white to the naked eye because myelin is composed largely of lipid tissue veined with capillaries. Its white color is due to...

 changes in the anterior cingulate cortex

Anterior cingulate cortex

The anterior cingulate cortex is the frontal part of the cingulate cortex, that resembles a "collar" form around the corpus callosum, the fibrous bundle that relays neural signals between the right and left cerebral hemispheres of the brain...

.

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

Zen and the Brain

Zen and the Brain: Toward an Understanding of Meditation and Consciousness is a book authored by James H. Austin. First published in 1998, the book's aim is to establish links between the neurological workings of the human brain and meditation....

(Austin, 1999). This has been confirmed using functional MRI imaging, a brain scanning technique that measures blood flow in the brain.

Theoria

Fifteen Carmelite nuns came from the monastery to the laboratory to enter a 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

Theoria

For other uses of the term "contemplation", see Contemplation Theoria is Greek for contemplation. It corresponds to the Latin word contemplatio, "looking at", "gazing at", "being aware of".- Introduction :...

). The results showed that far-flung parts of the brain were recruited in the sustaining of this mystical

Mysticism

Mysticism is the knowledge of, and especially the personal experience of, states of consciousness, i.e. levels of being, beyond normal human perception, including experience and even communion with a supreme being.-Classical origins:...

 union with God.

Meditation and EEG

Electroencephalograph

Electroencephalography

Electroencephalography is the recording of electrical activity along the scalp. EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain...

 (EEG) recordings of skilled meditators showed a significant rise in gamma wave

Gamma wave

A gamma wave is a pattern of neural oscillation in humans with a frequency between 25 to 100 Hz, though 40 Hz is prototypical.According to a popular theory, gamma waves may be implicated in creating the unity of conscious perception...

 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.

The experienced meditators also showed increased gamma activity while at rest and not meditating.

During meditation there is a modest increase in slow alpha or theta wave EEG activity.

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

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

Hilbert transform

In mathematics and in signal processing, the Hilbert transform is a linear operator which takes a function, u, and produces a function, H, with the same domain. The Hilbert transform is named after David Hilbert, who first introduced the operator in order to solve a special case of the...

, but also to a psychological state of personal renunciation.

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.

In 2000, Tloczynski et al. studied the perception of visual illusions (the Müller-Lyer Illusion and the Poggendorff Illusion

Poggendorff illusion

The Poggendorff Illusion is a geometrical-optical illusion that involves the misperception of the position of one segment of a transverse line that has been interrupted by the contour of an intervening structure...

) 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.

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.

Adverse effects

The following is an official statement from the US government

Federal government of the United States

The federal government of the United States is the national government of the constitutional republic of fifty states that is the United States of America. The federal government comprises three distinct branches of government: a legislative, an executive and a judiciary. These branches and...

-run National Center for Complementary and Alternative Medicine:

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.

Both positive rewards and potential benefits of meditation have been noted in academic literature. Adverse effects have been reported, and may, in some cases, be the result of "improper use of meditation". The NIH advises prospective meditators to "ask about the training and experience of the meditation instructor... [they] are considering."

Kundalini syndrome

Kundalini Syndrome

The Kundalini Syndrome is a set of sensory, motor, mental and affective symptoms reported predominantly among people who have had a near-death experience; it has also been attributed to practitioners of meditation or yoga.Researchers in the fields of psychiatry, transpersonal psychology, and...

 is a claimed adverse effect from practicing Kundalini Yoga

Kundalini yoga

Kundalini yoga is a physical, mental and spiritual discipline for developing strength, awareness, character, and consciousness. Practitioners call Kundalini yoga the yoga of awareness because it focuses primarily on practices that expand sensory awareness and intuition in order to raise individual...

.

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

Mindfulness (psychology)

Modern clinical psychology and psychiatry since the 1970s have developed a number of therapeutic applications based on the concept of mindfulness in Buddhist meditation.-Definitions:...

 acquired in meditation while actively engaging with current problems. 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.

Research methodologies

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

University of Alberta

The University of Alberta is a public research university located in Edmonton, Alberta, Canada. Founded in 1908 by Alexander Cameron Rutherford, the first premier of Alberta and Henry Marshall Tory, its first president, it is widely recognized as one of the best universities in Canada...

 Evidence-based Practice Center. The report reviewed 813 studies involving five broad categories of meditation: mantra

Mantra

A mantra is a sound, syllable, word, or group of words that is considered capable of "creating transformation"...

 meditation, mindfulness meditation, yoga

Yoga

Yoga is a physical, mental, and spiritual discipline, originating in ancient India. The goal of yoga, or of the person practicing yoga, is the attainment of a state of perfect spiritual insight and tranquility while meditating on Supersoul...

, T'ai chi, and Qigong

Qigong

Qigong or chi kung is a practice of aligning breath, movement, and awareness for exercise, healing, and meditation...

, and included all studies on adults through September 2005, with a particular focus on research pertaining to hypertension

Hypertension

Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...

, cardiovascular disease

Cardiovascular disease

Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...

, and substance abuse

Substance abuse

A substance-related disorder is an umbrella term used to describe several different conditions associated with several different substances .A substance related disorder is a condition in which an individual uses or abuses a...

.

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.

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

Validity

In logic, argument is valid if and only if its conclusion is entailed by its premises, a formula is valid if and only if it is true under every interpretation, and an argument form is valid if and only if every argument of that logical form is valid....

 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. 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 studies have found significant physiological differences between the two. It has been found that all approaches to meditation can achieve some non-specific benefits however the mental silence approach may be associated with additional specific benefits which are clinically beneficial.

External links

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