The Brain on Meditation

Dalai Lama

​Meditation is on the rise — though cautiously and in piecemeal fashion — across industrial culture. It’s Corporate America’s latest productivity booster and stress reducer. But by those already in its camp, meditation is held in far higher esteem than an efficiency hack. Some of mankind’s most enduring minds, from Confucius to Russell Simmons, hold varieties of introspection — the umbrella term subsuming all forms of meditation — as the only conceivable panacea to the unnecessary frictions of human life.

The rise of meditation in the West was greatly plagued by its largely subjective body of support. Ancient texts and personal experiences carry little weight in the scientific community (industrial society’s fulcrum of knowledge), and being told that society needs more introspection is hopelessly vague; what does that actually mean?

Meditation provides a distilled product of that ambiguous umbrella-term and is quickly garnering a wealth of scientific understanding. Advents in brain imaging techniques, among other innovations in neuroscience, forged what has remained, until recently, an elusive window into the meditative brain.​

 

The Neuroscience

The nascent yet expansive research covers a range of observed effects in response to meditation: the brain’s physical structure changes, neural pathways reconfigure, chemical balances shift, and atypical electrical activity spikes.

While meditation-induced physical changes in the brain are fascinating findings, any consistently repeated activity would likely cause associated neuroplastic effects. The excitement lies in the consistently desirable outcomes associated with these changes, substantiating the claims of meditation holding a broad ameliorative potential.

​Among the landslide of recent studies, the few reported here group into 3 main findings illustrating the neurological changes, benefits, and remaining mysteries of meditation. Supporting studies, excerpts of their key results, and brief summaries in jargon-less English are included below each relevant finding. Feel free to peruse any or all.

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Finding #1 — Meditation consistently increases both gray matter density and cortical thickness in key areas leading to, among other benefits, improved cognitive performance, greater longevity (subduing age-related neural decay), and even preliminary studies suggesting enhanced moral reasoning.

Supporting Studies:

“Is meditation associated with altered brain structure?” Fox et al. published in the June 2014 Neuroscience & Biobehavioral Reviews.

  • The study is significant because it represents the largest quantitative look at the body of meditation related research to date. The authors compiled results from 21 key studies comprised of hundreds of data points (in this case, “data points” refer to participating individuals whose brains were analyzed in relation to meditation’s effects) and established quantitative patterns indicating the specific brain regions typically affected, and the average magnitude of the observed changes.
  • From the study: “In the present study, we conclude that meditation appears to be reliably associated with altered anatomical structure in several brain regions. Moreover, these differences appear to be about ‘medium’ in magnitude (as measured by effect size). These effect sizes are comparable to the roughly ‘medium’ effects of many other behavioral, educational, and psychological interventions (Lipsey and Wilson, 1993), and may therefore indicate practical significance…”
  • From the study: “…we do find that meditation is consistently associated with changes in brain morphology…These include regions key to meta-awareness and introspection (RLPFC/BA 10), exteroceptive and interoceptive body awareness (sensory cortices and insular cortex, respectively), memory consolidation and reconsolidation (hippocampus), self and emotion regulation (anterior and mid-cingulate, and orbitofrontal cortex), and finally intra- and interhemispheric communication (superior longitudinal fasciculus and corpus callosum, respectively). Notably…consistent differences were found almost exclusively in higher-order (‘downstream’) executive and association cortices. This suggests that meditation preferentially recruits such general, higher-order brain regions.”

 

“Mindfulness practice leads to increases in regional brain gray matter density”, Lazar et al. published in the 2011 issue of Psychiatry Research: Neuroimaging.

  • Lazar’s 2005 study is among the original catalysts for quantitative analyses into meditation’s effects. She has since steadily published concise and significant findings on the topic, with the above study being her most cited recent study confirming gray matter effects.
  • From the study: “This study demonstrates longitudinal changes in brain gray matter concentration following an eight-week Mindfulness-Based Stress Reduction course compared to a control group. Hypothesized increases in gray matter concentration within the left hippocampus were confirmed. Exploratory whole brain analyses identified significant increases in gray matter concentration in the PCC, TPJ, and the cerebellum.”

 

“Neural Correlates of Post-Conventional Moral Reasoning: A Voxel-Based Morphometry Study”, Prehn et al. in PLOS ONE (2015)

  • From the study: “Results demonstrate that subjects at the post-conventional level of moral reasoning were characterized by increased gray matter volume in the ventromedial prefrontal cortex and subgenual anterior cingulate cortex, compared with subjects at a lower level of moral reasoning.”
  • The prefrontal cortex was a main area identified as exhibiting meditation-induced increases in gray matter density. This suggests a possible link between meditation and moral reasoning. Just food for thought.

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Finding #2 — meditation decreases gray matter volume in the right amygdala, the body’s primal stress center, inducing greater connectivity with the higher-order functions of pre-frontal cortex regions. Thus the role of stress in decision-making (as well as the body’s physical response to it) is diminished in favor of more thoughtful, complex, and uniquely human processes.

Supporting Studies:

“Dispositional Mindfulness Co-Varies with Smaller Amygdala and Caudate Volumes in Community Adults”, published by Taren et al. (2013) in PLOS ONE.

  • MRI imaging of 155 adults found that those who scored higher on the Mindful Attention Awareness Scale (designed to scale mindfulness) also displayed lower grey matter volumes in the right amygdala. Lesser grey matter in a particular region essentially indicates diminished connectivity between that area and the network of the whole. This minimizes not only the stress we feel, but the role it plays in our thought processes and decision making.
  • From the study: “Volumetric analyses showed that higher dispositional mindfulness is associated with decreased grey matter volume in the right amygdala… Such volumetric differences may help explain why mindful individuals have reduced stress reactivity…”

 

“Dispositional mindfulness and depressive symptomatology: correlations with limbic and self-referential neural activity during rest.” Published in Emotion (Way et al. 2010.)

  • Studying 27 young adults, the results indicate that those who’re relatively more mindful have lower baseline activity in the amygdala, and those who exhibit traits of depression have higher baseline activity in the amygdala. The working hypothesis being that the more active the amygdala is, the greater role stress plays in the mind’s landscape.
  • From the study: “…dispositional mindfulness was negatively correlated with resting activity in the amygdala, bilaterally, whereas depressive symptomatology was positively correlated with activity in the right amygdala.”

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Finding #3 — meditation generates gamma wave activity during practice, the amplitude of which increase over the meditation period. These heightened gamma oscillations persist, causing higher resting-state gamma wave activity in long-term meditators. Given how little we know about this wavelength, and the gist of preliminary theories, this finding holds the greatest potential of conferring meditation with the profound significance subjectively ascribed to it for ages.

 

A Word on Gamma Waves

Brain waves are neural oscillations, electrical impulses emanating from masses of neurons indicating that they’re at work doing something. Waves are measured in both frequency (cycles per second, or Hz) and amplitude (the size of each individual oscillation). A quick overview on what we know about the array of brainwaves helps to contextualize the gravity of finding #3.

Generally the lowest observable frequency, Delta waves (0.5–3 Hz) occur in states of sleeping, dreaming, and deep meditation. From 3–8 Hz are known as Theta waves, which are associated with daydreaming, meditation, and general disengagement from the sensory environment. Alpha waves (9–14 Hz) are considered the awake brain’s resting state, present though non-aroused. Beta waves (15–40 Hz) represent engaged mental stimulation, and were considered the highest observable frequency until Gamma waves were accidentally discovered in 1964 while studying monkeys. The subtlety of these Gamma waves (40–100 Hz, indicating small, quick waves) made them difficult to detect, thus there is little research or subsequent understanding regarding their nature.

EEG of meditative brain

Barry Kerzin meditating with EEG

 

Supporting Studies

“Long-term meditators self-induce high-amplitude gamma synchrony during mental practice”, published by Antoine Lutz et al., Proceedings of the National Academy of Sciences, vol. 101 no. 46.

  • From the study: “During meditation, we found high-amplitude gamma oscillations in the EEGs of long-time practitioners (subjects S1-S8) that were not present in the initial baseline… An essential aspect of these gamma oscillations is that their amplitude monotonically increased over the time of the practice…In addition to the meditation-induced effects, we found a difference in the normative EEG spectral profile between the two populations during the resting state before meditation.”
  • This 2004 study focused on the behavior of gamma waves pre, during, and post meditation between a control group of novice-meditators (1-week of training) and eight long-term Buddhist practitioners (15–40 years of training). Lutz et al. confirmed that meditation induces gamma oscillations, the amplitude of which increase proportionally to the time spent meditating (a trait considered the benchmark of determining cause-and-effect). This gamma activity recorded from the eight monks (observed between 25–40 Hz) represents the largest spike ever seen in humans in a non-pathological context. Far from exhibiting seizure-like traits, the subjects were simply sitting quietly as they displayed the largest and most mysterious surge of brain activity ever recorded. Washington Post has a good article giving more information on the study.
  • In addition, the study found that those with a long history of meditating had higher resting-state gamma activity. The authors aptly explain this finding:

​“It is not unexpected that such differences would be detected during a resting baseline, because the goal of meditation practice is to transform the baseline state and to diminish the distinction between formal meditation practice and everyday life.”

– Antoine Lutz et al. (2004)

 

“Occipital gamma activation during Vipassana meditation.” Cahn et al. Published in Cognitive Processing (February 2010, Volume 11, Issue 1, pp 39–56).

  • From the Study: “The current findings emphasize that in highly practiced Vipassana meditation practitioners, the primary effects of meditation state on brain rhythms are centered in the low (delta) and high (gamma) frequency ranges, with moderate relative increase in frontal theta, and gamma effects most pronounced in more advanced practitioners.”

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Conclusions

Too many similar, brilliant posts conclude with the same air of restraint endemic to the research they’re elucidating. This tendency betrays the very value of quasi-scientific articles: the ability to consider meditation’s subjective body of support in addition to the growing objective insight — something scientific papers cannot do. But how many subjective claims of meditation must be verified before we consider assimilating the entire array as a staple of the discussions? By neglecting this capacity we suppress the real excitement from all this neuroscience, which lies in the potentialities gaining ground beyond science’s constrained imagination.

Meditation is free, universally-available and potent; its the rare perfect storm of optimal simplicity and efficacy coinciding. Collecting support from both ends of the aisle (subjective & now objective), isn’t it time to consider that it may be more than just an efficiency hack? It may not just be a method of improving our established patterns, but reconfiguring them altogether – towards coexistence. It may be the paragon of technology, achieving what industrialism has (ideally) sought ever since its revolution: an enhanced quality of living. And for free, incidentally.

​“Meditation is freedom from thought and a movement in the ecstasy of truth. Meditation is explosion of intelligence.” 

– Jiddu Krishnamurti

Yongey Mingyur Rinpoche, a forefront Tibetan Buddhist Master spreading Asian philosophy westwards, puts this exalted notion of meditation back into the concept of introspection as mankind’s potential panacea:

“Who makes problems? We humans. And who is the controller of the human? The mind. And how to control the human mind? Through meditation. If you can control the pilot, then the pilot can control the plane.” 

– Mingyur Rinpoche

If the objective body of support continues growing at this rate, the day will soon come when we can no longer plead ignorance to meditation’s distinguished capacity for bettering human life.​

Why wait?

​Further Reading

If boring the audience wasn’t at stake, this list of pioneering studies could carry on much longer. For a better (though now dated) overview of the field and a thorough list of the exact structures reliably implicated in the meditation process, see Andrew Newberg and Jeremy Iversen’s 2003 paper. Andrew Newberg’s book, Principles of Neurotheology, is an awesome venture in establishing a dialogue between neuroscience and consciousness in a spiritual context, laying out most of the relevant works up until its publication in 2010. Finally, for an inbent inquiry into the broader dialogue between neuroscience and consciousness, check out David Chalmers’ Ted Talk (a really fascinating dude if you’re interested in the cognitive study of consciousness).

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