The practice of meditation is often viewed by Westerners as merely a form of relaxation. Many people assume that the benefits of meditation are limited to stress relief and decreased blood pressure. Brain research, however, is beginning to produce concrete evidence for something that Buddhist practitioners of meditation have believed for centuries: that mental discipline and meditative practice can physically change brain functioning and preserve and enhance numerous cognitive functions. Because it is often associated with transformed states, meditation has traditionally been understood in transcendent terms – as something outside the world of physical measurement and objective evaluation. But over the past few years, through the use of advanced new technologies, scientists have been able to come up with biological explanations for meditative phenomena. The results of several innovative studies reveal that the human brain has the ability to adapt and change in ways that were previously unimaginable. For a person with a neurodegenerative disease such as HD, these results suggest that it may be possible, by engaging in some sort of meditative practice or mental discipline, to maintain motor control and cognition and possibly delay the onset of many neurological symptoms. The following chapter examines the practice of meditation and its effects on the circuitry of the brain, as well as how this practice may potentially benefit someone with HD.
The Dalai Lama, Meditation, and Neurobiology^
The Dalai Lama, the head of state and spiritual leader of the Tibetan people (who practice Tibetan Buddhism), has played a pivotal role in opening the lines of communication between Western scientists and Buddhist scholars. Frequently, he calls leading psychologists and neurobiologists together to discuss the latest scientific thinking in fields related to the human mind. When he accepted the Nobel Peace Prize in 1989, he commented, “Both science and the teachings of the Buddha tell us of the fundamental unity of all things.” In fact, Tibetans in general seem to share this enthusiasm for science. Tibetans were surprisingly the most proportionately represented ethnic group working on the Human Genome Project. (For more information on the Human Genome Project, click here.) Even though they account for only 0.1% of the world’s population, they made up about 10% of the project’s workforce.
In particular, Tibetan Buddhist monks are interested in science because they have an intense curiosity about the workings of the brain. Monks typically spend hours in meditation each day, and claim that this practice enhances their concentration, memory, and learning ability. They believe that the brain is capable of being trained and physically modified in remarkable ways. Scientists used to believe the opposite – that connections among brain nerve cells were fixed early in life and that adult brains were more-or-less complete and unchangeable. When nerve cells died, it was believed that they were simply gone forever and could never be replaced. But that assumption has fortunately been disproved over the past decade with the help of advances in techniques such as brain imaging. In its place, scientists have embraced the concept of neuroplasticity, which refers to the brain’s ability to change its structure and function by expanding or strengthening connections between nerve cells that are frequently used and by shrinking or weakening those that are rarely engaged. It turns out that new nerve cells do grow and our brains are much more flexible than was once believed. A key component of Buddhist belief is that meditation literally transforms the mind. Thus, Buddhists are highly interested in scientific advances that could possibly help explain and/or provide evidence for this phenomenon. The question as to whether meditative phenomena have a biological basis is intriguing not only to the Dalai Lama and other Buddhists, but also to many neuroscientists. The collaborations between Western scholars and Buddhist monks are invaluable because the study of trained meditators can provide insights into the mechanisms behind important brain functions, as well as into possible therapeutic approaches related to lifestyle.
Neuroscientists and Buddhist monks: Results of an unusual collaboration^
The Dalai Lama, very much aware of neuroplasticity’s potential to interact meaningfully with Buddhism, encouraged monks to lend their brains to science so the workings of their meditating minds could be explored scientifically. Ultimately, he dispatched eight of his most accomplished practitioners to a neuroscience laboratory to have them hooked up for electroencephalograph (EEG) testing and brain scanning. The tools with which cognitive neuroscientists measure brain activity have grown very sensitive, allowing scientists to observe differences in brain activity between individuals doing the same task or even between different trials with the same individual. The Buddhist practitioners in the experiment had undergone training in meditation for an estimated 10,000 to 50,000 hours, over time periods of 15 to 40 years. As a control, 10 student volunteers with no previous meditation experience were also tested after one week of training.
Electrical activity and brainwaves^
Davidson et al (2004). The monks and volunteers were fitted with a net of 256 electrical sensors and asked to meditate for short periods. Thinking and other mental activity are known to produce slight, but detectable, bursts of electrical activity as large groupings of nerve cells send messages to each other, and that is what the sensors picked up. Richard Davidson, head of the experimental neuroscience laboratory, was especially interested in measuring gamma waves, some of the highest-frequency and most important electrical brain waves.
It is well known that the brain has electrochemical properites. A fully functioning brain can generate as much as 10 watts of electrical power. Even though this electrical power is very limited, it does occur in very specific ways that are characteristic of the human brain. Electrical activity emanating from the brain is displayed in the form of brain waves. Brain waves, or the “EEG,” are electrical signals that can be recorded from the brain, either directly or through the scalp. These brainwaves are organized into categories, ranging from the most active to the least active in terms of frequency.
The frequency of the brainwave, measured in cycles per second, is associated with its speed. Different frequencies indicate different levels and types of activities. Delta waves have a very low frequency (below 4 hertz) and occur during sleep. Alpha waves, 8 to 13 hertz, occur at relaxed, quiet times. Beta waves, 15 to 40 hertz, are the next fastest, occurring when we are actively thinking. Gamma waves (greater than 40 hertz) have the highest frequency and are involved in higher mental acuity, including perception and consciousness. They are thought to play an essential role in nerve cell communication.
The brain contains hundreds of billions of nerve cells. Researchers believe our thoughts are created when large groupings of these nerve cells “fire,” or send messages to each other, through bursts of electrical activity at the same frequency. Many scientists believe that synchronized neural firing, which occurs when masses of nerve cells fire or emit electrical signals at the same frequency at the same time, lies at the root of numerous essential cognitive functions, including memory and perception. Gamma wave activity, in particular, exerts a powerful influence on the brain because the production of gamma waves involves thousands of nerve cells moving at extremely high speeds in unison. Interestingly enough, Davidson found that the gamma waves in the monks showed much greater activation, and the movement of the waves was far better organized and coordinated than in the non-meditating students. The meditation novices showed only a slight increase in gamma wave activity while meditating, while some of the monks produced gamma wave activity more powerful and of higher amplitude than any previously reported in a healthy person in the neuroscience literature.
In addition to frequency, brain waves can also be measured in terms of amplitude, which describes the size of the wave. It is thought that brain wave amplitude is related to the amount of nerve cells present, as well as the degree of synchronization, with which the nerve cells fire. In other words, when an individual has a lot of nerve cells that fire well together, the size of the brain waves will be larger than when there are fewer nerve cells or when the nerve cells are not firing well together. The fact that the monks showed such high amplitude gamma wave activity is significant because it indicates that not only do they have a lot of healthy nerve cells, but these same nerve cells are also firing with a high degree of synchronization. Synchronizations of neural firing at high frequencies (gamma waves) are thought to play a crucial role in integrating scattered neural processes into a highly ordered cognitive act such as memory and in inducing synaptic changes. In other words, when nerve cells are firing with a high level of synchronicity (as they were in the monks’ brains), brain cells are able to communicate with each other much more readily and the entire brain is able to function more efficiently. It is important to note, however, that the potential benefits of increased gamma wave activity are based upon inferences that have yet to be proven. More research needs to be done.
Davidson has done follow-up studies and has concluded that meditation (along with increased gamma wave activity) results in a redistribution of gray matter in the brain, as well as a decline in the loss of gray matter. The decline of gray matter, which is natural but accelerated in HD, mirrors a decline in cognitive function and processing ability. The brain has two main layers: gray matter and white matter. The layer of gray tissue surrounds a whitish core, like the peel of an orange around its juicy interior. Gray matter is the command and control center of the brain where all the nerve centers are located. White matter, composed mainly of transmission facilitating sheaths known as myelin, simply connects the gray matter together. In the gray matter, we have motor-controlling cells and damage to these cells results in stroke. Stroke can paralyze any muscle that you can voluntarily move, including those of speech. It has been found that individuals with HD typically have a substantially reduced volume of gray matter in the brain, especially in the temporal lobe and the frontal lobe.
In fact, the decline in gray matter is so closely tied to the progression of HD that it may serve as a marker for the degree of brain atrophy. In other words, by measuring the amount of gray matter loss, researchers may be able to predict not only how much the HD has progressed, but also how much the brain has atrophied. This connection is likely due to the fact that an important brain structure known as the caudate nucleus is situated deep in the gray matter. The caudate nucleus is a nerve center that is essential for controlling movement and cognitive processing and has been investigated heavily by HD researchers. When the gray matter volume is reduced, this structure becomes less able to carry out its functions. Because it connects to many different parts of the brain, this inability to function can have widespread effects. Deterioration of the caudate nucleus and its connections to other parts of the brain results in behavioral changes and the inability to control emotions, impulses, thoughts, and movements. When it becomes damaged, the individual may be unable to experience intense feelings of guilt, shame, or embarrassment and be unaware of mistakes that are evident to others. This inability may result in a lack of self-awareness and an inability to evaluate one’s own behavior, in addition to making social and personal relationships more difficult. HD researchers have also found that damage to the caudate nucleus makes it difficult for people with HD to prioritize tasks and organize their day, as well as to handle many simultaneous stimuli. Additionally, the caudate nucleus controls voluntary movement. (For more information on the caudate nucleus, click here).
As you can now see, the caudate nucleus is an extremely important structure in the brain and its deterioration (as a result of gray matter loss) directly leads to many common HD symptoms. It follows that any type of activity or treatment that is able to delay or prevent a loss of gray matter would also delay or prevent many common HD symptoms. Aging invariably leads to some gray matter loss, but this process is significantly accelerated in people with HD. Hence, it would be highly beneficial for a person with HD to incorporate activities into his/her life that may be able to prevent such a rapid loss of gray matter. Again, it is important to note that meditation has not been proven to preserve gray matter and this claim is based largely on the findings of a single researcher. Yi Rao, a neuroscientist at Northwestern University, says that the science of meditation is “a subject with hyperbolic claims, limited research, and compromised scientific rigour.” Rao further goes on to say that, “Davidson is a respectable scientist, but he has put his respectability on the line with this.” Davidson defends his work as the first step in a new field. “Meditation research is in its infancy.” There needs to be a lot more peer-reviewed research findings in order for Davidson’s claims to be substantiated.
Meditation and everyday life^
After reading about meditations’ potentially significant influence on the brain, many readers are probably at least a little bit curious about how to implement meditation into their own lives. As a word of caution, the possibility that there was a pre-existing difference in brain function between the monks and the novices in the study can’t be ruled out. In other words, there may have been a confound in the study because individuals who have high levels of gamma wave activity to begin with may be more likely to become monks. However, the researchers are fairly confident that this is not the case because the monks who had spent the most years meditating had the highest level of gamma wave activity. This “dose response” – where higher levels of a drug or activity have greater effect than lower levels – is what researchers look for to assess cause and effect. Thus, the researchers are also confident that anyone who begins to meditate will be able to experience its benefits. Unfortunately, practicing meditation can be incredibly daunting for novices because they think they have to achieve some form of transcendent state. The monks, however, insist that their state of mind isn’t dependent on any superhuman leaps into higher consciousness. It’s much more pragmatic than that: it’s as simple as training the mind to think differently.
The monks describe meditation as simply a form of mental exercise. Pichitr Thitavanno, a prominent Buddhist, explains, “Despite the importance of the mind, most people appear to take care of the body far more than the mind, often neglecting its exercise or training. They have three meals a day, take a bath twice, provide the body with clothes for the purpose of adornment in a variety of ways, and give it regular and well planned exercise in the form of sports and walking. Even in the case of medicine, the body as a rule receives priority in care and attention, with the mind all this time being neglected and regarded as almost nonexistent. The mind is left uncared for until it becomes dusty, dirty, and polluted because of lack of exercise, training, and development.” In light of this fact, Buddhism introduces the ways and means of strengthening and exercising the mind. Buddhists believe that a mind well-trained and strengthened in the proper manner will help bring peace and progress both to the individual and to society as a whole. It is important to note that Buddhists do not believe that one must become a Buddhist in order to experience the benefits of meditation. Similarly, Davidson believes that the monks’ brains differed so dramatically from the novices not because they are Buddhists who practice meditation, but because they frequently engage their minds in mental training. In other words, meditation serves as a form of mental exercise that strengthens the brain, in much the same way that running or working out serves as a form of physical exercise to strengthen the body.
It is very important to note that meditation isn’t just performed by Buddhists. Nor is there only one form of Buddhist meditation. Nor does one have to believe in the other precepts of Buddhism to benefit from some of the Buddhist methods of meditation. There are secular meditation courses as well as religious.
Just as physical exercise can seem daunting to a person who has never worked out before, mental exercise such as meditation can seem daunting because it is unfamiliar and may feel unnatural. The key is to start off slow and come up with a routine that suits you. It is also important to realize that there is no right way to meditate; there are many different traditions of meditation and many different ways to meditate. In Davidson’s study, he had the novices practice mindfulness-based meditation, which is a state of alertness in which the mind does not get caught up in thoughts or sensations, but lets them come and go, much like watching a river flow by. This type of meditation is a good way for beginners to start. To begin, sit quietly for 10 to 20 minutes while concentrating on a single object or on the flow of your breath. When your mind begins to wander, note the new thought or sensation and then gently bring your concentration back to your original focus.
Another major form of meditation known as Vipassana, which means to see things as they really are, is one of India’s most ancient techniques of meditation. It was taught in India more than 2,500 years ago as a universal remedy for universal ills. The practice, which was taught by the Buddha, is non-sectarian and has universal application. It does not require conversion to Buddhism. While the meditation practices themselves vary from school to school, the underlying principle is the investigation of phenomena as they manifest in the five aggregates: matter or form, sensation or feelings, perception, mental formations, and consciousness. This process leads to direct experiential perception.
Another major form of meditation is that of Shambhala. Shambhala training is a nonsectarian path of spiritual training that emphasizes the cultivation of fearless, gentle, and intelligent action in the world. This action arises out of trust in innate human goodness and the inherent power and sacredness of the world, connecting with both through meditation practice as well as mindful activity in everyday life. Shambhala training welcomes people of all religious traditions as well as those who follow no particular spiritual path.
The practice of Japa meditation is the technique of using mantras (sounds) to open the heart and mind. The repetition of the sound is supposed to calm the senses and the mind and affect the chemistry of the body. One does not need to be religious to experience the benefits of Japa meditation. Mantras (sounds) can be whatever one chooses – they do not need to be religious mantras. For example, during an inhalation, one might say “I am” and during an exhalation one might say “at peace.” This practice allows the mind to focus and concentrate, and clear away other thoughts, emotions, and distractions which normally divert energies.
The unusual collaboration between psychiatrist Richard Davidson and several Buddhist monks unveils the possibility that the brain, like the rest of the body, can be altered intentionally. Davidson and his colleagues put forth the idea that the phenomena of meditation can be translated into high-frequency gamma waves and brain synchronization, or coordination. Additionally, he found that meditation results in a redistribution of gray matter in the brain, as well as a decline in the loss of gray matter. These data suggest that meditation may induce short-term and long-term neural changes. These neural changes allow nerve cells to communicate and operate more effectively, thereby protecting and prolonging the vitality of the brain and several important brain functions. This finding is hopeful and encouraging for people with HD because it shows that there are things that can be done to actively combat the disease. Just as physical exercise sculpts the body and increases physical health, mental exercise sculpts the brain and increases mental health. With sufficient mental exercise and training, it is possible that the onset and progression of several common HD symptoms can be delayed. Meditation simply serves as a form of mental exercise; the key is to frequently train the mind. In the future Davidson hopes “to better understand the potential importance of this kind of mental training and increase the likelihood that it will be taken seriously.”
For Further Reading
- Cyranoski, David. Neuroscientists see red over Dali Lama. Nature 2005; 436: 452.
- Lutz, A., Greischar, L.L., Rawlings, N.B., Ricard, M., & R.J. Davidson. “Long-term meditators self-induce high-amplitude gamma synchrony during mental practice.” Proc Natl Acad Sci. 2004; 101(46): 16369-73.
This paper describes the study in which Davidson’s lab used EEG testing on Buddhist monks and novices. It is fairly easy to read, but it does go into detail about high amplitude gamma waves and synchronizations.
- Thitavanno, Pichitr. A Buddhist Way of Mental Training. (Self-Published). 2002
This book was written by a Buddhist monk and it describes the Buddhist philosophy, as well as the basics of mental training.
This site describes the various types of brain waves and also contains several news articles about the relationship between meditation and the brain.
The Mind and Life Institute is dedicated to creating a powerful working collaboration and research partnership between modern science and Buddhism: the world’s two most powerful traditions for understanding the nature of reality and investigating the mind. Contains links to articles, conferences and events, news articles, books, and research initiatives
- Wallace, Alan. Buddhism and Science: Breaking New Ground. Columbia University Press, NY: 2003.
This book brings together distinguished philosophers, Buddhist scholars, physicists, and cognitive scientists to examine the contrasts and connections between the worlds of Western science and Eastern spirituality.
-D. McGee, 4-30-06; recorded by B. Tatum, 8/21/12