How mindfulness changes the brain
I admit I was a skeptic. I kept reading all the articles about Jon Kabat-Zinn’s mindfulness-based stress reduction (MBSR) program and how it was beneficial for every medical condition imaginable including arthritis, chronic back pain, and even hot flashes. My curiosity about this wonder treatment was piqued. I kept reading the new research studies and subsequently moved to New York City and started working in a clinic for individuals with anxiety disorders. If you live in Georgia, it was very much like the one that you may know about. Mindfulness is one of the skills taught to individuals with anxiety; it provides a way to distance themselves from emotions and accept that emotions such as anxiety ultimately pass and don’t last forever. As the girl who used to leave yoga class before savasana (relaxation at the end)—terrible, I know, I was that girl?!—I thought I should learn how to practice mindfulness myself, so that I could at least practice what I was preaching. I told myself I had to do the homework because if I got to the end of the eight weeks and my life hadn’t changed, I would have no one to blame but myself. So I suffered through four weeks of doing an hour-long body scan daily while my mind behaved like a drunk monkey that had been bitten on the tail by a scorpion. Much to my surprise, after four weeks, everything shifted. My thoughts started settling. The two things I found the most stressful about NYC—grocery stores (people who live in Manhattan behave as though it is Russia and there isn’t enough food) and public transportation—suddenly were easier. I was less irritable. I was sleeping better. I was sold.
This article is for the skeptics like me. Research has literally exploded in the last several years examining how mindfulness (the psychology term used to describe awareness of the present moment) and meditation (the broader practice) change the brain. We used to think that brain development ended around age 25; now we know just how flexible the brain is and how activities such as exercise and meditation can promote new functions, connections, and even structure. This ability is called neuroplasticity and describes the ability of the brain to physiologically change over time in response to the environment and behavior.
There are several brain networks that act in concert to regulate our experience. The cognitive control network includes prefrontal regions (towards the front of your brain, behind your forehead) and serves the function of the linear thinker/problem-solver. The emotional salience network includes regions deep in the brain like the amygdala that detects emotional stimuli and decides how relevant they are to you and your current experience. The default mode network is the network that is running when we “aren’t doing anything,” meaning in the absence of an explicit external task. The default mode network includes regions such as the posterior cingulate cortex, and these regions contribute to mind-wandering and other types of self-referential thinking. In other words, the default mode network governs what we tend to do with our minds when we aren’t really paying attention to anything in particular.
When these networks are healthy, the cognitive control network downregulates the emotional salience network and tells it when to chill out; and the default mode network knows when to turn off and lets the cognitive control network pay attention to the outside world. Among individuals with anxiety disorders, the emotional salience network seems to be working overtime, with less input from the cognitive control network. Depressed individuals spend too much time focusing on how bad they feel and are too in tune with internal stimuli at the expense of external stimuli. In other words, their default mode network is working overtime.
The ability to switch between internal and external tasks involves a key region of the default mode network called the posterior cingulate cortex. This region has been directly linked to meditation practice. Cutting-edge research uses real-time functional magnetic resonance imaging (fMRI) to examine what this region is doing during meditation. A friend, practitioner, and colleague, Judd Brewer, used real-time fMRI with novice and experienced meditators to conduct a study at Yale University in 2013. While individuals were meditating he showed them a visual display of what their posterior cingulate cortex was doing. He found that the posterior cingulate cortex was active when people became caught up in thought and quieted when they were meditating. In fact, the type of meditation did not seem to matter so much. Across different forms of meditation (concentration, loving-kindness, choiceless awareness), he found that meditation involved quieting the posterior cingulate cortex. So science tells us that quieting this region is required to dip into the bliss of selflessness.
Meditation influences brain activity during different tasks but also influences the connections between brain regions and the strength of various networks. Additional work by Brewer in 2014 examined the specific technique of loving-kindness. When asked to practice loving-kindness in the scanner, experienced meditators exhibited different connectivity patterns when compared with novice meditators. Novice meditators had greater connections within their default mode network, whereas this was not the case among experienced meditators. Meditation practice is also associated with increased connectivity between the dorsolateral prefrontal cortex, a key hub in the cognitive control network, and the insula, a key region in the emotional salience network involved in detecting and sorting through emotional stimuli. Meditation appears to improve the brain’s ability to complete emotional and cognitive tasks as well. For example, research in 2013 by Rimma Teper and Michael Inzlicht at the University of Toronto found that meditators demonstrated better cognitive control and more emotional acceptance.
Meditation changes not only the function of brain networks but their structure. Long-term meditators exhibited greater gyrification in a study conducted at UCLA in 2012 by Eileen Luders. Gyrification is a process of cortical folding and is believed to support greater intelligence because it allows for the greater surface area of neurons within the same skull volume. In this study, gyrification increased as the number of years practicing meditation increased.
As the evidence for the benefits of meditation and how it changes the brain has grown, the question has shifted to whether or not you need to be an expert who has practiced for 10,000 hours or whether your brain can experience benefits prior to reaching the expert phase. A study by Sara Lazar at Harvard in 2011 found that just eight weeks of practice resulted in structural brain changes including thicker cortices in prefrontal regions and the insula. Similar to gyrification, thicker cortexes are associated with a greater number of neurons and theoretically greater function in these regions.
Meditation even helps delay cognitive decline and aging. A review in 2014 conducted by Andrew Newberg at Thomas Jefferson University summarized evidence suggesting that meditators do not experience the typical decline in gray matter volume and a parallel decline in attentional performance with age. Thus, meditation may have a neuroprotective effect, reducing the cognitive decline typically associated with increased age.
Overall, this research suggests that the mental training that occurs through meditative practice is associated with changes in brain function and even structure. One of the primary mechanisms through which meditation functions is the turning down of the “over-selfing” of the default mode network. Research also illustrates that meditators improve their attention and emotion regulation and that these changes may be long-lasting, persisting beyond time spent on the cushion.
Richard Davidson, a key researcher in this growing field at the University of Wisconsin, says the goal of this research is “to use what we know about the brain to fine-tune interventions that will improve well-being, kindness, altruism. Perhaps we can develop more targeted, focused interventions that take advantage of the mechanisms of neuroplasticity to induce specific changes in specific brain circuits.”
I’ll OM to that.
originally published in Yoga Chicago in 2014