It has been well established that meditation changes brain structure and connectivity. Researchers are making progress in understanding more about the specific parts of the brain meditation effects and how these changes benefit cognitive function.
A new pilot study by researchers at Harvard's Beth Israel Deaconess Medical Center identifed that the brain changes associated with meditation and subsequent stress reduction may play an important role in slowing the progression of age-related cognitive disorders like Alzheimer's disease and other dementias. The results of the study were published online recently in Neuroscience Letters.
"We know that approximately 50 percent of people diagnosed with mild cognitive impairment—the intermediate stage between the expected declines of normal aging and the more serious cognitive deterioration associated with dementia—may develop dementia within five years. And unfortunately, we know there are currently no FDA approved medications that can stop that progression," says first author Rebecca Erwin Wells, MD, MPH, who conducted her research as a fellow in Integrative Medicine at Harvard Medical School.
Wells explains, "We were particularly interested in looking at the default mode network (DMN)—the brain system that is engaged when people remember past events or envision the future, for example—and the hippocampus—the part of the brain responsible for emotions, learning and memory—because the hippocampus is known to atrophy as people progress toward mild cognitive impairment and Alzheimer's disease. We also know that as people age, there's a high correlation between perceived stress and Alzheimer's disease, so we wanted to know if stress reduction through meditation might improve cognitive reserve."
Participants of the study were randomized into two groups. One group participated in Mindfulness-Based Stress Reduction (MBSR) using meditation and yoga, the other group received traditional care. The MBSR group met for two hours each week for eight weeks. They also participated in a day-long mindfulness retreat, and were encouraged to continue their practice at home for 15 to 30 minutes every day.
All participants in the study underwent a functional MRI (fMRI) at the beginning of the study and then again after eight weeks to identify any changes in the size of brain structures or in brain connectivity
There are a variety of definitions for mindfulness and types of mindfulness training. One of the most widely recognized definitions is by Dr. Jon Kabat-Zinn who pioneered (MBSR) and describes mindfulness as: “Paying attention, in a particular way, on purpose, in the present moment, and non-judgmentally.” For more on the definition of mindfulness please check out this link to the Mindfulness Research Guide (MRG).
Meditation Improves Brain Connectivity and Prevents Brain Atrophy
Previous studies have shown that the hippocampus is activated during meditation and that people who meditate have a higher concentration of hippocampal gray matter. "So the big question is, is it possible for MBSR to help attenuate the decline of individuals already experiencing some memory problems?" asks Wells.
The results of fMRI imaging showed that the group engaged in MBSR had significantly improved neural connectivity in the brain areas related to the default mode network. As expected, both groups did experience atrophy of the hippocampus, but those who practiced MBSR experienced less atrophy.
The researchers also did tests of memory, but this study was not designed to see actual memory differences between the two groups, though, Wells and colleagues previously reported that, "most data suggest a trend toward improvement for measures of cognition and well-being."
"This is a small study and more research is needed to further investigate these results, but we're very excited about these findings because they suggest that MBSR may reduce hippocampal atrophy and improve functional connectivity in the same areas of the brain most affected by Alzheimer's disease. MBSR is a relatively simple intervention, with very little downside that may provide real promise for these individuals who have very few treatment options," says Wells.
She concludes that future studies will need to be larger and evaluate cognitive outcomes as well. "If MBSR can help delay the symptoms of cognitive decline even a little bit, it can contribute to improved quality of life for many of these patients."
Different Types of Meditation Have Different Brain Benefits
There are many different types of meditation and mindfulness training. For example, you could do a mindfulness meditation that focuses mostly on breath, or you could do a loving-kindness meditation (LKM) which focuses more on sending loving and compassionate thoughts to yourself and others. Other types of meditation include: Vipassana, Zen, Transcendental Meditation (TM), Zazen, Kundalini... Personally, I like to do a hodge-podge of different meditation techniques during each session to reap the benefits of each.
Each type of meditation or mindfulness has slightly different brain benefits. Among other types of meditation, researchers have been studying the specific benefits of loving-kindness meditation (LKM) and how compassion improves vagal tone and can create an upward spiral of well-being.
Personally, I like to meditate to a 15-20 minute soundtrack on my iPod with instrumentation and a background of people chanting “Om” or “Aum.” The musical track gives the mindfulness training a distinctive begin and end, which allows me to lose myself in the middle. The daily routine of putting the music on, sitting in my favorite chair, in a specific way.... encodes the process into procedural memory of my implicit ‘habit brain’ which makes it an automatic ‘non-thinking’ daily routine.
When I do mindfulness training, I do a blend of: Relaxation Response, MBSR, and loving-kindness meditation. For LKM, I would encourage you to systematically go through a 4-step process of directing loving, compassionate, and forgiving thoughts to four categories of people: 1. Loved Ones. 2. People with whom there is conflict or tension. 3. Strangers. 4. Yourself.
I find that each category taps a different neural network and brain area. Each group feels very different when you are meditating. You can almost feel a tectonic neural shift matched by changes in your breathing as your compassionate focus moves through these four groups—something I'm sure could be seen with advanced neuroimaging.
As with any type of training, creating a personalized meditation or mindfulness daily routine that fits your personality, lifestyle, and becomes a habit is the key to sticking with it.
Conclusion: Cognitive Resilience Requires a Multipronged Approach
Neuroscientists around the world are doing cutting edge research to figure out what lifestyle choices can improve cognitive function at every stage of life. As I put the pieces of this puzzle together, it seems clear that in order to optimize brain plasticity, connectivity, and neurogenesis (growth of new neurons) everybody needs to take a multipronged approach. The core tenets of optimizing cognitive function seem to be a combination of age-appropriate daily activities that flex a variety of neural networks and brain areas during every stage of life.
A simple way that I am creating a drug-free prescriptive for optimizing cognitive function is to focus on daily activities (including sleep) that engage each of your brain’s four hemispheres and, in doing so, maximize neural volume and connectivity of your entire brain. Daily habits that bulk up and strengthen connections between the gray and white matter of the left and right hemispheres of the cerebrum and cerebellum will inherently also benefit the size and connectivity of the hippocampus. This creates a state of cognition and consciousness that I call "Superfluidity."
One caveat, based on other research on implicit and explicit learning and memory, it is appears that an overemphasis on mindfulness training alone might impede types of learning that are implicit or automatic. Also, physical activity, having a strong social network, mastering new skills and stepping outside of your comfort zone all increase brain volume and maintain cognitive strength as we age.
Meditation and mindfulness training are clearly an integral part of a recipe for long-term cognitive health—but people with mild cognitive impairment should also be encouraged to stay physically active, creative, and socially connected. A wide variety of daily lifestyle choices have the power to increase volume and connectivity between brain areas that can lead to a lifespan of mental and physical well-being.
If you’d like to read more on this topic, check out my Psychology Today blogs: