Can Meditation Change the Brain?

In any standard biology or neuroscience text book, one will read that the electrical and chemical signals in the brain shape its structure and function. These signals, based on how neurons are connected through synapses, determine our thoughts, our actions, and our physiology. Until recently, it was thought that certain parts of the adult human brain are not capable of regeneration. It is now becoming clear that some regeneration does occur in all parts of the adult human brains. In light of this, another question has been asked: can our thoughts and actions influence brain structure? When one learns, thinks, or acts, does the brain undergo anatomical and physiological change as the neurons strengthen their connections with each other or make new ones? Through various methods, such as EEG and functional MRI (fMRI), scientists have now started to get a glimpse of the answer.

Meditation is a mental state of being in which the individual has a sense of heightened awareness. In Buddhism, the ultimate goal of meditation is to achieve Nirvana, or enlightenment, a “state of mind that is free from craving, anger, and other afflictive states” (1). In attempting to achieve Nirvana, meditation leads to spiritual growth, and is believed to reduce negative emotions, promote relaxation, increase the feeling of compassion, and generate physiological benefits. It has lately been asked whether meditation, which is a mental task, can make changes in brain structure. Since meditation is strong associated with religion, researchers have often shied away from studying it scientifically. However, recently, in part through the efforts of the Dalai Lama, there has been an increase in research related to identifying the neural correlates of meditation. This paper will discuss some of the current research and what light meditation can shed on brain function.

If one thinks about the nature of mediation, certain predictions can be made about what the neural correlates may be. During focused meditation, one needs to focus on a particular object. In trying to focus, one needs to keep their attention on the chosen object, as well as monitor their mind so that they know when they have lost focus and their mind has wandered off thinking about something else. The meditator also must be able to move their mind away from the distraction and refocus on the original object. Thus, it can be expected that brain activity would be present in the parts of the brain related to these tasks. However, other questions arise. Do other parts of the brain also activate? What other cognitive changes can meditation bring about? Does this activation last beyond the time of meditation?

Richard Davidson of the University of Wisconsin, Madison, has been at the forefront of research on meditation. His lab uses EEG and fMRI to measure the changes in brain structure and function as a result of meditation. In one study (2), EEG was used to measure brain activity of long term Buddhist meditation practitioners compared to the bran activity of beginners. The subjects were asked to meditate on compassion, which is different from focused meditation. Objectless meditation “cultivates a state of being” in a way such that “the intentional or object oriented aspect of experience appears to dissipate in meditation” (2). It was found that long term meditators emit high amplitude gamma rays while meditating. These emissions were not found in the baseline and are characteristic of states in which the brain is involved in tasks related to attention, learning, and perception (3), thus suggesting that they “are flexible skills that can be trained” (2). It is also thought, but not yet tested, that different types of meditation may produce different types of brain activity.

In addition, Lutz and colleagues found there was a difference in the brain activity when the subject was not meditating between the long time practitioners and the beginners. This seems to be consistent with the objective of meditation, which is to “transform the baseline state and to diminish the distinction between formal meditation practice and everyday life.” (2). In other words, meditation seems to cause permanent changes to the brain, i.e., it is not just the brain that gives rise to thoughts and actions, but they in turn, can also alter the brain.

In collaboration with other researchers, Davidson’s research group has also found that meditation activates the prefrontal cortex, which decreases negative emotions and increases positive emotions. This study also explored how meditation affects immune function. There were two groups of subjects: one group which underwent an eight week training program in mindfulness meditation, and a control group. For both groups, brain activity was measured before and after the training program (and at the same time points for the control group) after which the subjects were given the influenza vaccine. It was found that subjects in the meditation group produced more antibodies than those in the control group, thus showing that meditation also has positive effects on the immune system, and endorsing its role in general well-being.

More recently, Davidson and colleagues have started to use fMRI to as a method to determine the neural correlates of meditation. Functional MRI measures blood flow in the brain to determine areas of brain activity while doing a particular activity. In one study, they explored neural correlates of concentration meditation in long term practitioners (Buddhist monks) and beginners. It was found that in all participants, meditation causes activation in regions related to attention. A very interesting finding was that some of these areas showed an inverted u-shaped curve. Long term meditation practitioners with a larger amount of hours of practice showed less activation, as did the beginners. The long term practitioners with less amount of hours of practice, however, showed a stronger activation. This relationship is often seen in the acquirement of other skills, such as language skills. It also suggests that “after extensive…meditation training, minimal effort is necessary to sustain attentional focus” (4). This research suggests that meditation is a skill and like learning, can cause changes in the brain.

The scientific study of meditation is still in its infancy and further research is required to obtain an in-depth view of how meditation can alter the brain, both structurally and functionally. The data so far suggests that meditation does indeed cause certain changes in the brain, such as activating areas associated with attention and positive emotions (even when not meditating). The study of meditation can lead to great insights on the workings of the brain and help seek treatments for disorders. For example, this research has potential clinical applications for patients with severe depression since a treatment may be to stimulate areas related to positive emotions and relieve the symptoms.  In order to make the present data more substantial, more research must be conducted. To rule out individual differences, “longitudinal studies examining changes over time within the same individuals” (4) should be done. Different types of meditation should also be studied to determine if they have different effects and if they can be used change the brain in such a way so as to develop cognitive skills. Also it would be interesting to study whether there are age and/or gender differences, that is, if meditation has different effects (or degrees of effect) depending on what age it is practiced at and what the gender of the practitioner is. Meditation can provide a window into the workings of the brain in a unique way.  So far the research has been able to answer some basic questions, but it has also generated deeper questions and future investigations are necessary to answer them.


References
1) "Nirvana." Wikipedia, the free encyclopedia. 20 Feb. 2009 <http://en.wikipedia.org/wiki/Nirvana>.

2) Lutz, Antoine, Lawrence L. Greischar, Nancy B. Rawlings, Matthieu Ricard, and Richard J. Davidson. "Long-term meditators self-induce high-amplitude gamma synchrony during mental practice." PNAS 101 (2004): 16369-6373.

3) Meador, K. J., P. G. Ray, J. R. Echauz, D. W. Loring, and G. J. Vachtsevanos. "Gamma coherence and conscious perception." Neurology 59 (2002): 848-54.

4) Lutz, Antoine, Heleen A. Slagter, John D. Dunne, and Richard J. Davidson. "Attention regulation and monitoring in meditation." Trends in Cognitive Sciences Xxx (2008): 1+.

5) Brefczynski-Lewis, J. A., A. Lutz, H. S. Schaefer, D. B. Levinson, and R. J. Davidson. "Neural correlates of attentional expertise in long-term meditation practitioners." PNAS 104 (2007): 11483-1488.

6) Conze, Edward. Buddhist Meditation. Minneapolis: Dover Publications, 2003.

7) Davidson, Richard J., Jon Kabat-Jinn, Jessica Schumacher, Melissa Rosenkranz, Daniel Muller, Saki F. Santorelli, Ferris Urbanowski, Anne Harrington, Katherine Bonus, and John F. Sheridan. "Alterations in Brain and Immune Function Produced by Mindfulness Meditation." Psychosomatic Medicine 65 (2003): 564-70.

8) Davis, Jeanie L. "Meditation Balances the Body's Systems." Health and Balance. WebMD. 17 Feb. 2009 <http://www.webmd.com/balance/guide/transcendental-meditation>.

9) Hall, Stephen S. "Is Buddhism Good for Your Health?" 14 Sept. 2003. The New York Times. 17 Feb. 2009 <http://query.nytimes.com/gst/fullpage.html?res=940CE1DB173BF937A2575AC0A9659C8B63>.

10) Lynch, Casey. "Mind Your Brain - The Neuroscience of Meditation." Brain Waves. 28 July 2005. Corante. 18 Feb. 2009 <http://brainwaves.corante.com/archives/2005/07/28/mind_your_brain_the_neuroscience_of_meditation.php>.