It’s important to understand that while meditation may be a simple experience it is not, from a neuro-mechanical point of view, a simple process. It involves many different parts of the brain, each dealing with specific functions, and specific interconnections between those parts. So we first need to take the idea of meditation and break it down into its basic neurological components. These components are:
- Focused attention (most, but not all, meditative methods involve focused attention).
- A sense of physical relaxation.
- Reduced negative feelings and increased positive feelings.
- A change in the usual pattern of mental activity.
- In the case of SY, the change in mental activity is intended to transition to the experience of mental silence, i.e. a profound reduction in mental activity that occurs in conjunction with increase alertness.
Now the brain science tells us that some of these components — particularly focused attention, relaxation and shift in mood — occur in most meditation methods and therefore it is common to see those areas of the brain become activated during meditation, regardless of which technique is being studied. In addition, there is also research that shows that different techniques can often involve different areas of the brain. Furthermore, the way in which these areas become involved and interrelate with each other can also differ between techniques. This, of course, raises the question about which pattern of brain activity is good for us, bad for us or of no consequence. As yet, no single unified understanding has emerged that explains all the different approaches to meditation and their often different effects on the brain.
For example, a 2004 study of eleven Tibetan Buddhist monks in meditation showed intense gamma wave activity in certain parts of the brain REF. Yet a study of people using a mindfulness form of meditation, also a Buddhist activity, showed alpha activity — at the opposite end of the spectrum to gamma — which was more prominent in the left frontal side of the brain compared to the right REF. In short: two kinds of meditation, both claiming to be Buddhist in nature, yield electrical activity at opposite ends of the spectrum and in similar parts of the brain. A study by Fenwick of a different form of meditation seemed to show electrical changes that resemble sleep REF. Does that mean that meditation is a form of sleep? Yet another study revealed episodic electrical activity that mirrored epilepsy-like patterns REF.
It seems logical that if different forms of meditation create different activation patterns in the brain, they are likely to have different effects. Is one pattern of activation better than another? Might one be more useful in certain circumstances compared to another? These questions have yet to be answered, regardless of what you may read in the media. Short-term studies are manifestly unable to show what those different effects might be. Long-term studies, on the other hand, are difficult and expensive to do and yet they are clearly essential to answer these questions.
What we can say, regardless of the uncertainty about long term effects, is that the rather popular idea that all forms of meditation are the same is untrue. Different forms of meditation can activate the brain differently. The practical upshot of this question is: “Which pattern of activation do you want? Or which pattern of activation is good for you?”. While we don’t know for sure, common sense would lead us to conclude that the research outlined in this book is a reasonable indication that the brain activation patterns associated with mental silence are both desirable and beneficial.
Comparing apples with apples
Setting aside the likelihood that different meditation techniques activate the brain differently, there is the even bigger question about whether or not meditation’s effects on the brain are unique to meditation or common to all practices that involve, say, focused attention — or sitting still with eyes closed or thinking positive thoughts — have yet to be answered by brain science. Once again, for us to get definitive answers about whether or not meditation has a unique effect on the brain, we must first develop a clear definition about what meditation really is. This is why I feel that the mental silence definition of meditation is of such potential importance.
While various meditation techniques have been shown to involve certain parts of the brain and certain activation patterns, similar changes have often been observed in non-meditative activities as well.
For example, when a person does a meditation technique that involves focused attention, there will be activation of those parts of the brain that drive and support the focusing of attention. Most researchers will agree that the one thing that appears to be common to all meditation techniques is the activation of a region of the brain in the limbic system called the anterior cingulate gyrus; this is a brain centre whose function is, among other things, to support focusing of attention. This seems logical, since most meditation techniques involve some kind of manipulation of attention. However, reading a book or doing a mathematical calculation also activates the same area of the brain because we need to focus our attention for those tasks to be done as well. Logically, then, focused attention alone is not an adequate definition of meditation.
Similarly, meditation techniques might involve parts of the brain that govern relaxation of the body, but so do non-meditative activities such as listening to music, relaxation or slow, deep breating.
What aspect of meditation, and its resulting impact on the brain, is therefore truly specific to meditation and not other things? We can’t answer this question, I feel, until we come up with a specific and consistent definition of meditation. So you can see that the emergence of brain imaging, and its potential to answer our questions about meditation, actually reinforces the importance of dealing with those fundamental questions that I described in chapter XX concerning the need for a clear definition of meditation. The idea of meditation as mental silence is both conceptually specific and, when have tested it scientifically, manifestly specific in its practical effects as well. The brain research regarding it, described below, adds further weight to my argument that it is a legitimate definition.
Do umbrellas cause rain?
Another important issue that affects the quality of meditation research, in fact this is relevant to the entirety of the new field of brain science, is the simple fact that just because two areas of the brain appear to activate (or deactivate) at the same time does not mean that one causes the other. Yet this assumption is frequently made when the brains of meditators are observed to show certain patterns of activation, leading over-eager scientists and under-qualified journalists to jump to conclusions about what kind of brain changes meditation might cause. It’s a bit like making an observation that whenever it rains, we see a lot of umbrellas outside, and so conclude that umbrellas cause rain. Or observing an athlete sprinting in a race and conclude that the reason for his movement along the track is because his arms are moving when in fact it is his legs that are propelling him and the arm movements are just providing balance. It sounds like common sense but when faced with the glossy, high tech equipment and the glare of the media it is precisely our commonsense that can get bamboozled.
Quantity over quality
Until researchers choose a consistent set of standards by which meditation is studied — including the imaging modality, the definition and other considerations — it will be very difficult to bring all the different findings together into one coherent picture.
There is currently no uniformity in the way that studies of the brain in meditation have been conducted. Many are interesting but quite poorly designed despite the pretty pictures. They often have insufficient numbers of participants or don’t properly control for confounding factors, hence the results are fascinating but not reliable enough to allow firm conclusions about meditation to be made. A smaller number, however, have been designed and conducted very well- including some looking at Sahaja yoga and mental silence, which we will look at later in this section. Many of the well-designed ones don’t allow for good cross-comparison with other well-designed studies since they often involve very different modalities — fMRI studies involve generating images of the areas of brain that are using oxygen, EEG looks at electrical activity on the surface of the brain only and PET studies use radio-labelled glucose. They aren’t cross comparable. The devil is in the detail, as they say.
I feel that the challenge is not so much about the technology so much as the need for a consistent standard to be applied to all meditation studies that will allow different understandings of meditation to be compared to each other as well as to other non-meditation practices. These studies should also be connected to practical outcomes whether they are health related, such as depression, or performance related, such as attention span or learning ability.
By understanding the challenges, limitations and caveats around the brain sciences, and brain imaging, we can better appreciate the significance of what some of the discoveries have told us about meditation, mental silence and the brain.