For more than fifty years now, scientists have become more and more interested in meditation and its effects on the brain, about which 3,000 scientific studies have been published so far. DR RENÉ DESCARTES summarizes this research and the techniques used, in order to measure the physiological changes meditation brings and to explore its clinical benefits.

In recent years, many scientific publications have emphasized the benefits of meditation. Though meditation is traditionally associated with spiritual growth, it is often used as a relaxation technique and a stress management strategy. Many advantages have been described, in fact they are so promising that meditation is apparently a panacea, an activity that requires no equipment, has no side effects, and can be practiced by anyone after a short initial instruction, without any constraints of time or place.

In spite of the thousands of publications since the 1970s, some of which are very interesting, considerable research work remains to be done to explore and verify these positive results. We often don’t realize the extreme constraints imposed by high-quality scientific research. In particular, sufficient numbers of subjects are required in any study before we can generalize the findings to an entire population.

Also, meditation cannot be reduced to something objective. Moreover, between the subjective experience and outside observations performed with measuring equipment there is a philosophical discrepancy that should be given some thought. Spiritual seekers could refuse to be locked up in MRI equipment, and purely materialistic scientists could claim that meditating merely consists in getting embroiled in one’s illusions and projections.

Despite all these challenges, it is exciting to elaborate on the contributions of science in this rapidly expanding domain. In recent years, many publications have been covered in popular media, so much so that the general public now knows that meditation and science can come together.

Let’s define meditation, and identify the part it currently and potentially plays in the medical sector, after briefly reviewing the current scientific research. Finally, we shall try to answer a few practical issues, particularly with regard to a method tailor-made for everyone.

The attention we pay to our inner world
can be purely receptive and passive,
or well focused on a particular object
(a part of the body, breathing,
an image, a mantra) or
even based on developing a particular
feeling such as empathy, benevolence,
love, a non-judgemental attitude, etc.


Dozens of technical processes for meditating have been identified, but they all have a common denominator: looking inward. Newcomers will often pay attention to the external environment. Through meditation, the participant turns inwards, trying to ignore any outside stimulus. The meditator will develop the attitude of a neutral observer, thus becoming both the subject and the object of the experiment.

Underneath this apparent simplicity, we are dealing here with a complete change in attitude. As a matter of fact, beginners often rate meditation as being extremely difficult. There is actually no moment in our lives when we are asked to adopt apparent ‘non-activity’ while being utterly aware, which is the difference between sleep and meditation.

The attention we pay to our inner world can be purely receptive and passive, or well focused on a particular object (a part of the body, breathing, an image, a mantra) or even based on developing a particular feeling such as empathy, benevolence, love, a non-judgmental attitude, etc.

These elements define three main families of meditation. Some types of meditation propose mixed approaches.


It took only a few dozen years for medicine to move from insufficient means to technological superabundance. Diagnostic capacities have developed so much that it is now possible to dramatically change the course of events, particularly as far as acute diseases are concerned. Think of our current approach to heart disease and the emergency interventions that now allow an interventional cardiologist to save the heart muscle, a muscle that could not regenerate by itself after having suffered from a lack of oxygen. Not such a long time ago, for want of means, we treated the pain and let the disease take its destructive course. Nowadays, the number of deaths prevented and the reduction of disease-specific mortality have been impressive, as stents and other techniques make it possible to dissolve blood clots and have proper blood flow restored.

Yet, along with such remarkable improvements in the domain of emergency medicine, multiple complex and chronic diseases exist for which therapies are scarce and often quite inadequate.

For instance, treating pain has not changed much. Although analgesic medication is better known and prescribed, it is unsatisfactory as it is fraught with very adverse effects. Therefore, as regards chronic diseases, there is obviously a major need for new therapeutic tools, and not necessarily medicinal ones.


Research has mainly focused on answering the question: is meditation a unique practice, which allows us to reach a particular condition different from other common states of consciousness, or is it a mere sleep-like state of relaxation? We know that some meditators, after having practiced regularly, have felt they were reaching very specific conditions, sometimes extremely pleasant ones, such as distortions of time and space, the feeling that they were floating, etc. Some neuroscientists questioned the possibility to ensure such states are fully objective. Wouldn’t they be mere ordinary subjective experiences, like those you can have during sleeping and wake phases? What can be really measured and objectified in a person who is meditating?


It measures the electrical activity in the brain. It was first used in the 1920s by Hans Berger, and gave the possibility to differentiate brain waves types and therefore to understand and define brain electrical activity within healthy subjects. It allowed researchers to establish what abnormal electrical brain activity was like and better understand the wide range of epilepsy. The question that naturally arose was: does meditation trigger any particular electrical activity that is different from other states? In a healthy subject, four basic states were roughly differentiated: the state of anxious wakefulness with a predominance of beta waves (13-30 Hz), the deep relaxation state, with a predominance of alpha waves (8-13 Hz), the state of paradoxical sleep (REM sleep), with a predominance of theta waves (4-8 Hz), and a deep-sleep state with a predominance of delta waves (0.1-4 Hz).

Now, for people who meditate, significant modifications may already be observed after a few weeks, though they are hardly specific and rather akin to relaxation and hypnosis states. For example, a larger frequency band of alpha waves and a slowing down of the waves are noticeable, and after a few weeks practice, there is a significant onset of theta waves during meditative states. Such modifications make sense: a downturn in thoughts, which become less intrusive, less obsessional, will entail a slowdown in the brain waves influx. Recently, however, improvements in  measurement have enabled us to bring to light the presence in meditators’ brains of large amplitude waves, faster than beta waves and known as gamma waves (>30 Hz). Any normal individual will have some range of frequency of gamma waves, generally from 30 to 40 Hz, with low amplitude of ongoing oscillatory activity. These waves are thought to be a convergence of neural networks. Such electrical activity is thought to indicate neural plasticity, and usefully allow a long-term storage of information in memory circuits. This would happen during raining, for instance. The gamma waves found in highly experienced meditators, however, have a faster frequency, between 60 and 110 Hz, and larger amplitudes. They are deemed to be the signature of unique and very specific changes due to a longterm meditative practice. We don’t precisely know yet what these high frequency waves really mean, but their location makes us think they indicate an intensified capacity to focus.1


This technique allowed the first exploration into the brain. But it is mainly through functional magnetic resonance imaging that we have been able to study not only the brain structure but also the way it all functions, by analyzing some located minute changes in the blood flow within the brain. These various methods have made many modifications easy to spot and describe, which we cannot cover here. Meditation activates some areas of the brain and deactivates others. Some of the changes are associated with certain types of meditation and not others. Certain zones in the brain may show a slightly increased size due to meditation, but it is only with experienced meditators that the effects of meditation become really significant.


These include measuring the electrical resistance of the skin, respiratory rhythm detection, magneto-encephalography, oxygen consumption, and cardiac coherence through a study of heart rate variability. Such measurements have helped shed light on further effects of meditation. Meditation has a calming effect on the nervous system, and it also calms many other physiological systems: heart, blood circulation and the activity of the autonomic nervous system. Thanks to such methods, it has been possible to show the difference between a meditative state and the state of a hypnotic trance.

The benefits are multifold:
improved sleep quality,
decreased depression,
reduced attention deficit
hyperactivity disorder
(ADHD), anxiety, addiction,
chronic pain, blood
pressure, etc.


Qualitative research is becoming better recognized and utilized, allowing a crosschecking of quantitative data and the creation of a real spiritual science. If we apply the sociologists’ methods, for example, we could compare the reports of a considerable number of practicing meditators and find commonalities between the different subjective moments they lived. Such an approach would also have the advantage of not presenting meditation only as an experience measurable by devices, however sophisticated those devices may be.


Beyond the measurable effects of meditation on our system and brain function, great attention has been paid to its tangible clinical benefits. Several dozen have been assessed and considered for further investigation, and the resulting studies show the potential benefits of a meditative practice on almost all branches of medicine. The benefits are multifold: improved sleep quality, decreased depression, reduced attention deficit hyperactivity disorder (ADHD), anxiety, addiction, chronic pain, blood pressure, etc.

Among other studies, I would like to mention the research published in 2012 in the American Heart Association Journal, which tried to establish the benefits of meditation in preventing a recurrence of myocardial infarction. On the basis of two daily sessions of 20 minutes each, after 5 years of follow-up, a decrease of 48% in the number of accidents was determined in the group practicing meditation versus a control group.2

Note that some publications indicate unwanted side effects linked with a meditative practice, for example, an eerie feeling of depersonalization. Fortunately, these effects seem to be very rare and appear to be related to insufficient training.


The first clinical studies carried out in the seventies focused on Transcendental Meditation. Certain members of worldwide successful rock bands such as the Beatles and the Beach Boys practiced TM and meditation came to benefit from a first and significant wave of notoriety, attracting in its wake its first researchers. But since the period was characterized by a great number of excesses, meditation also developed an ambiguous reputation in the eyes of the general public.

A lot of research has shown that the various families of meditation have different effects on the brain. But these results mainly concern beginners. Many researchers now accept that the changes observed in experienced people are similar no matter what the method of meditation practice.Here, the term ‘experienced’ means that the person has been practicing meditation regularly for a dozen years or more. The changes seen endure and are considered as being very specific.

Many meditation methods have been laboratory tested, but most of the clinical studies done concern the Mindfulness method. Though its structured protocol has made it very popular in academic and medical circles, the effects obtained from the Mindfulness method did not particularly stand out from those of other types of meditation.

Heartfulness yogic practice, which is beginning to arouse interest amongst researchers, though very simple, comes forward as a synthesis of the three groups of meditation. Its attention is focused on the source of light in the heart, and it has the advantage of very rapidly creating a steady state in those who meditate. The early investigations carried out by scientists have opened up a bright future for further research.

Moreover, hundreds of thousands of meditators all over the world have confirmed the capacity to rapidly attain a very deep meditative condition thanks to yogic transmission, sometimes from the very first session, or at least after only a few weeks or months of regular practice.

It may also be stressed that a meditative practice could have multiple benefits for caregivers and during intervention. The quality of decisions taken is greatly enhanced by a centered and relaxed attitude. Meditation is not only a safeguard against many evils, it is also much more than a simple therapeutic process, according to several studies, and it can also improve academic performance.

But is that really why we meditate? Is there any question of improving performance or is meditation something more? What about an integrated development of emotional and spiritual potentialities?



C. Braboszcz et al. 2017. Increased Gamma Brainwave Amplitude compared to Control in Three Different Meditation Traditions, Toulouse University, Research Center on Brain and Cognition.

Schneider, R.H. et al. 2012. Stress Reduction in the Secondary Prevention of Cardiovascular Disease Randomized, Controlled Trial of Transcendental Meditation and Health Education in Blacks. American Heart Association Journal, USA.

3 Fell, J, et al. 2010. From Alpha to Gamma: Electrophysiological Correlates of Meditation-Related States of Consciousness. Medical Hypotheses (75), pp. 218-224.

Thimmapuram, J. et al. 2017. Effect of Heartfulness meditation on burnout, emotional wellness, and telomere length in health care professionals. Journal of Community Hospital Internal Medicine Perspectives, USA.


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