The Science of Mindfulness

The best way to understand mindfulness is to practice it. After all, it has over 4500 years of experience behind it. Yet, we all learn and develop trust in our experience in different ways. This is one of the reasons why it’s important to validate and challenge our observations and assumptions with strong scientific research. As Kristin Neff, PhD so aptly put it, “Science gives our thinking brain explanations for why we feel how we feel, reduces the self blame and shame, and creates motivation to create new habit patterns.” Fortunately for the science minded, mindfulness has been studied now for over 40 years and has consistently demonstrated positive outcomes associated with:

• decreased levels of perceived stress and anxiety
• strengthened attentional focus
• increased self-awareness and emotional regulation
• reduction in symptoms of various physical and behavioral health conditions (including anxiety, depression, chronic pain, and heart disease) and in risk factors that could lead to more serious chronic ailments

The biological science behind the benefits of mindfulness meditation is showing us why it can be so effective in reducing stress and anxiety. There are a number of mechanisms proposed for how this happens. Most animals share in common basic threat processing circuitry that helps us survive and live long enough to reproduce in a challenging world. Especially in humans, there is also a cognitive mechanism involving interpretation and choice. Mindfulness practice impacts our experience of stress on both levels.

The practice of mindfulness helps us learn to regulate aspects of our central nervous systems so that higher reasoning is available for better decision making. The threat response system tends to be highly reflexive and our baser instincts aren’t always appropriate in meeting the stressors of the modern world. The brain systems that are activated when we feel threatened tend to hijack and overwhelm our higher reasoning. The central nervous system’s fight/flight/freeze reactions are calmed when we are mindful. This allows us to access the neocortex (or rational brain) rather than responding from the more primitive parts of the brain.

A 2014 study by Zeidan, et. al. took snapshots of brain activity using FMRI technology. These snapshots showed that, during periods of anxiety and stress, the prefrontal cortex (PFC) and anterior cingulate cortex (ACC) tended to be deactivated. These parts of the brain are involved in self-regulation or the ability to exert some voluntary control over our thoughts (such as worries) and emotions (such as anxiety). They also found that the posterior cingulate cortex (PCC) was highly activated during during anxious states. This part of the brain is associated with mind wandering and self-referencing. Interestingly, after 20 minutes of mindfulness meditation guided by an experienced and trained facilitator, the PFC and ACC showed greater activation, the PCC was deactivated, and state anxiety was significantly reduced.

In a study of unemployed people who were looking for a job (Taren, et. al., 2015) and who were provided a 3-day intensive mindfulness meditation training intervention, FMRI studies showed:

• a greater degree of connectivity between the ACC and the amygdala (an almond shaped part of the limbic system involved in processing emotions) was associated with increased stress
• after mindfulness training, this connectivity was decoupled and there was greater activation of the prefrontal brain regions (the executive control center of the brain) as well as reduced activity in the emotion centers.

The Default Mode Network (DMN) is the circuitry in our brain that’s active when we are self-referencing, making judgments, and thinking about the past and future. These functions become problematic when we get stuck in ruminating and worrying, being overly self-critical, or getting caught up in judging and blaming – factors related to a number of mental health disorders. Meditation is correlated with reduced activation and functional connectivity of the DMN (Brewer et. al. 2011). When the DMN is quiet, the Task Positive Network (TPN) is engaged, focusing attention on the present moment, such as when we meditate on the breath or other body sensations. With repetition, we learn how to switch out of doing into being mode, interrupting painful patterns of thinking and behavioral habits that cause us stress.

Its interesting to note that in an interview called “The Untold Story of America’s Mindfulness Movement: Then, Now & the Future” moderated by David Gelles of the New York Times, Dr. Richard Davidson, who pioneered now famous research on the brains of Buddhist monks, said he has never monitored the efficacy of his own mindfulness practice in his neuroimaging studies of meditators. He said he would rather trust his own “internal signals” in regards to his personal practice. I think this is a very telling statement. Indeed, the ancient wisdom that the modern practices of mindfulness spring from has been called ehipassiko, which in Pali means “come and see for yourself.”

Resources

Brewer, J. A., et. al. (2011). Meditation experience is associated with differences in default mode network activity and connectivity. Proceedings of the National Academy of Sciences of the United States of America, 108(50), 20254–20259.

Taren, A. et. Al. (2015). Mindfulness meditation training alters stress-related amygdala resting state functional connectivity: a randomized controlled trial. Soc Cogn Affect Neurosci. Dec; 10(12):1758-68.

Zeidan, F., Martucci, K. T., Kraft, R. A., McHaffie, J. G., & Coghill, R. C. (2014). Neural correlates of mindfulness meditation-related anxiety relief. Social cognitive and affective neuroscience, 9(6), 751–759.