Healthy Brain, Happy Life (38 page)

The neuroscientists wanted to see if there was any difference between the patterns of brain waves in the monks compared to those in the controls as both groups did the same meditation. The difference, it turned out, was like night and day. Of course, there were more gamma waves present in the brains of the monks relative to the novice meditators. In fact, the level of gamma activity was off the charts—the monks exhibited the most powerful gamma waves that had ever been seen in normal, nonpathological humans. This finding showed that there was indeed a dramatic difference between the brains of expert and novice meditators. These findings suggested that the extensive amount of training and meditation that the monks did resulted in the development of prominent gamma waves, which may reflect the monks’ higher levels of awareness and mindfulness. But another possibility is that the monks were born with a propensity for more gamma waves that predisposed them to deep meditation, which in turn drove them to become monks. In other words, the brain waves of these monks might have started out different from birth. While this widely referenced study could not differentiate between these possibilities, other randomized control studies that compared the effects of meditation to no meditation in two equivalent groups of subjects have confirmed that the practice does cause a number of different kinds of brain changes.

OBJECT-BASED VERSUS OPEN MONITORING MEDITATION

It turns out that while there are many different kinds of meditation, the practice can generally be separated into two broad categories. The first category is often called focused attention meditation, which, as the name suggests, centers on the act of directing and sustaining your attention on a particular object. This is a very common form of meditation, often used in yoga classes when the instructor asks you to focus on your breath while pushing all other wandering thoughts away.

The second form of meditation is considered more advanced and is called open monitoring meditation. This practice can start with a focused attention meditation to calm the mind, but then the focus of attention moves from an object (that is, your breath) to a particular state, in the case of this study, to the state of loving kindness and compassion.

To start a loving kindness meditation, you first picture someone in your mind who you know and love or have known and loved in the past. It can work with an adult, but I find it works particularly well to picture a baby. Now, just savor the feeling of joy and totally uninhibited love that you feel toward that baby. If a human baby or a loved person in your life is not working for you, then puppies, kittens, or other baby animals might do the trick.

Once you have a feeling of loving kindness and compassion flowing through you, try to develop that same feeling toward others. You can start with the easy targets, your closest friends and family members. Then you practice directing feelings of loving kindness toward a stranger, like the person sitting next to you on a flight or the waiter who serves your meal. Then the hard part comes. You direct loving kindness toward someone you are having difficulty with or even hate. Of course, this last step could take months, years, or even a lifetime to master. That is okay.

A mantra that accompanies the loving kindness meditation is: “May you have happiness. May you be free from suffering. May you experience joy and ease.”

You can offer these words to everyone in your focus during the loving kindness meditation. Good luck on this journey!

WHAT DOES MEDITATION REALLY DO FOR OUR BRAINS?

Although the gamma wave differences between the monks and the novice meditators are striking, this study did not provide specific information about the brain areas that might change with meditation. Gamma wave studies don’t provide precise information about the brain areas sending the signals. fMRI studies have been done to help identify the areas and specific functions that change with meditation. One study compared brain activation in a group of meditators with at least three years of practice (not as expert as the Tibetan monks, but still pretty good) to nonmeditators. This study asked if there were differences in brain activity as subjects were performing a task of selective attention in which they had to quickly switch their focus from one thing to another. The surprising finding was that there was less activation in the frontal lobes during this task for the meditators than for the control group. This might seem counterintuitive at first, but it actually makes sense. If expert meditators have better control over their attention, they require less effort and, therefore, less activation to move their focus to different objects quickly.

But as I asked before, what if all these differences between the expert meditators and the novices were due to the fact that people who become expert meditators have brains that are wired differently from the rest of us (this is the same question that came up with the London cab drivers way back in Chapter 1)? To address this question, one study examined the effects of an intense meditation training (five hours a day for months) versus no such training in a group of volunteers between twenty-one and seventy years old who were all familiar with intensive meditation practice. These people were clearly not novice meditators, but it was a well-designed randomized control study nonetheless. Researchers randomly assigned the participants to either intense meditation or not to determine if the intense practice would improve attention and visual discrimination. This study clearly showed that the people in the intense meditation group had improved in both tasks relative to the control group. Another study with a similar randomized control design examined brain activity using fMRI as subjects focused on their breath, a very common meditation practice. In fact, the insula, located deep in the lateral (side) part of the brain, is known to be involved in attention toward internal bodily functions (for example, respiration or digestion). This study showed that meditation practice increased activation of the insular cortex relative to nonmeditators during a breathing practice. These are two examples of a growing body of studies suggesting that meditation training can change the brain activity of a random sample of people relative to no meditation training. But we will need many more similar studies to fully characterize the changes that occur with both short- and long-term meditation training.

Other studies focused on meditation alone have examined the effect of the practice not only on patterns of brain activation using fMRI but, just like the studies on exercise, also on brain size. For example, a number of studies have reported that different kinds of meditations result in increases in cortical volume (brain size increases). One study focused on people who had been practicing loving kindness meditation for at least five years. Researchers reported bigger volumes in the right angular gyrus and the posterior parahippocampal gyrus, brain areas associated with empathy, anxiety, and mood. Another study comparing expert meditators and nonmeditators found larger brain volumes in the right anterior insula, in the left inferotemporal gyrus, and in the right hippocampus.

Another study examined the effects of eight weeks of meditation in inexperienced meditators and found that, compared to before the program, participants showed increases in gray matter in the left hippocampus and posterior cingulate cortex.

You might wonder why all these studies are reporting different brain changes with meditation. One important note is that the studies used different forms of meditation, which makes direct comparisons across the research difficult to do. There are so many different kinds of meditation, and each kind could have its own set of unique brain effects. We have to be systematic about the kind of meditation that we study to start to sort this question out.

These challenges are similar to the impact of different forms of exercise. What is the difference between Nordic walking versus treadmill running versus spinning class on the results of scientific studies? Findings suggest that, although evidence shows that both exercise and meditation ultimately produce positive brain changes, there is still much work to do on specifying all the brain effects of the many different forms of exercise and meditation out there. We have our work cut out for us.

Taken together, all this research on the neurobiology of meditation tells us something quite extraordinary about the brain. We already know that aerobic exercise that changes so many physiological functions in our body—from heart rate to respiration to body temperature to muscle activity to the level of constriction and dilation of the blood vessels—can change the brain in striking ways. What the studies reviewed in this chapter show is that you don’t have to move one finger to see brain plasticity at work. In fact all you have to do is sit very still and focus your mind, which results in significant changes in electrical activity, anatomy, and behavioral function. In a sense, that’s even more surprising and more powerful than the changes seen with exercise. For me this is probably the most profound example of the great degree of plasticity that the brain is capable of.

AN EXERCISE–MEDITATION SMACKDOWN

I am often asked whether exercise or meditation is better for your brain. What happens if you pit the raw physical power of aerobic exercise against the steely calm of meditation in a head-to-head, no-holds-barred, good old-fashioned smackdown? In fact, that was the question I kept asking myself. I had a strong exercise regimen and a growing meditation practice. I felt great, and I wanted to know why. What parts of my brain were changing because of exercise and what parts were benefiting from meditation? Was there one that was better for my brain?

The first important thing to note is that while we can study the effects of aerobic exercise on brain function in both animals and people, we don’t have the luxury of studying meditation in animals—they don’t meditate! Because of this fact, more is known about the detailed cellular and molecular mechanisms underlying exercise. Of course, in meditation’s favor is the fact that it is a practice that has been around for thousands of years, and there is currently significant interest in this field.

Several recent studies out of Stanford have already compared the effects of exercise and meditation. One study compared a form of meditation called mindfulness-based stress reduction to aerobic exercise for improving mood in patients with social anxiety disorder (SAD), which is a common condition characterized by intense fear of evaluation and avoidance of social or performance situations. Using a randomized control design, the experiment showed that both meditation and exercise groups showed significantly fewer symptoms of SAD and better measures of well-being relative to the untreated control group. In other words, after both exercise and meditation, the subjects in these groups rated themselves higher in measures of well-being than did the people in the control group. In this study, both exercise and meditation appear to have similar effects on mood and well-being in subjects with SAD.

Although previous studies have shown that exercise improves attention function in elderly adults, a follow-up study showed that for people suffering from SAD mindfulness-based meditation may be more effective at improving attention than is exercise. In this study, researchers compared the effects of mindfulness-based meditation to aerobic exercise using fMRI to determine which parts of the brain became activated when participants tried to regulate their emotional responses about their own negative self-beliefs. The purposes of the study were (1) to determine which intervention (exercise or meditation) decreased participants’ reactivity to statements of negative self-beliefs and (2) to observe the pattern of brain activity as participants responded to these negative statements. The researchers found that people with SAD who engaged in the mindfulness-based meditation showed less negative emotional response (as judged by themselves) while they were trying to regulate their reactions to their own negative self-beliefs than did the exercise group. In addition, the scientists noticed that the meditation group showed more brain activation of the parietal lobes (important for attentional regulation) than did the exercise group. The results suggest that meditation might enhance the attentional regions of the brain, allowing the individuals with SAD to better regulate their emotions toward negative self-beliefs. Although the participants in this study had SAD, all of us can benefit from the ability to better regulate our attention, particularly in emotional situations. We will need further studies to determine if the same benefit is also seen in normal control subjects who undergo meditation training.