Guest posts / health / research / sleep

Thinking clearly: What is mindfulness all about?

Do you ever just wish you could get someone who knows virtually everything that’s known about the brain and quiz them about mindfulness? Well, I do – a lot – and I just got my wish!

It is my pleasure to present this interview with John McBurney MD. A practicing physician with of over 35 years’ experience, he is board certified in Neurology, Clinical Neurophysiology and Sleep Medicine. Dr. McBurney maintains a daily mindfulness meditation practice as well as home yoga practice.

Could you describe the neurological response to mindfulness practice?

Mindfulness practice ultimately comes down to the concept of neuroplasticity.

In mindfulness, in cultivating awareness of the breath and voluntary moment by moment awareness of the brain, we are training the brain – just like when you are learning to play the violin or any other complex skill – we are training to break out of those self-referential ruminative recursive mental states and to achieve an orientation toward the outer world and in the present moment rather than anticipating the future or reliving the past.

contemplative neuroscience mechanisms behind mindfulness

 Could we be losing something by focusing more on the external realities rather than the self?

Occasionally, we do hear of adverse experiences arising from mindfulness. With any robust intervention there are always potential risks.

How long does it take for mindfulness to have a noticeable effect?

The results can happen almost immediately, however, they are also cumulative. We are still figuring out what the minimum effective dose is. 

What is the relevance of the changes in functional connectivity in the brain in someone who has devoted  a monumental amount of time to meditation, such as Tibetan monks, who may put in more than 10,000 hours in to their practice, compared to the likes of you and me?

A very neat study was published by David Cresswell in Biological Psychiatry in 2016. They invited individuals with high level of stress, unemployed adults, to a weekend retreat experience. They were randomised to in 2 groups:

  • a 3 day mindfulness retreat (the treatment group) and
  • a 3 day relaxation retreat where they read stories, told jokes and had a good time (the control group).

The study was conducted in one centre over one weekend, so it is well controlled. Initially, both groups rated the interventions as being equally helpful to them, subjectively.

The researchers looked at the functional connectivity between the dorsolateral prefrontal cortex and the cingulate gyrus. They also looked at Interleukin-6, a known marker of inflammation, that has been previously shown to be elevated in stressed out unemployed people.

Even with this brief weekend mindfulness intervention, the treatment group developed increased connectivity between the dorsolateral prefrontal cortex and the cyngulate gyrus. There was a neuroplastic response even after a 3 day mindfulness retreat. This was also associated with a decrease in the marker IL-6. Even after 4 months, IL-6 was decreased in the treatment group, but in the control group, IL-6 levels continued to rise, independent of whether they managed to get a job or not.

This is also relevant to doctors, who are at high risk for burnout. Because of their work commitments, the mindfulness retreat for doctors was condensed from the standard 8 week model developed by John Kabat-Zinn to a weekend intervention. The question was: does the weekend model work? The research at the University of Wisconsin where this was developed was reassuring: the residents are less stressed out, more effective and have a greater level of satisfaction.

We still don’t know the absolute minimum dose, but it seems that a weekend of mindfulness can be life-changing for the brain.

Another paper published in PLOS ONE from the Benson-Henry Institute for Mind Body Medicine in Harvard looked at the practices such as meditation, prayer, mindful yoga, Tai-Chi, Qi Gong, etc, i.e. ones that elicit a relaxation response (as opposed the stress response).

This study showed that in both novice and experienced practitioners of relaxation response modalities, there were changes in the epigenetic transcription of the genome. There was upregulation of pathways associated with mitochondrial integrity, downregulation of inflammatory pathways, improved insulin-related metabolism and improved nitric oxide signalling.

Long term potentiation, the standard mechanism for memory formation, strengthens existing neural connections. This happens immediately, as you read this. Over time, long term potentiation leads to formation of new connections,through synaptogenesis, dendritic arborisation and neurogenesis i.e. brain structure changes. In turn, this affects the most neuroplastic neurons located in the hippocampus.

mindfulness minimum effective dose response neurology

In reference to this fascinating recent study of the fight or flight response, it seems plausible that breathing regulates our stress levels much more than conscious thought. Could you explain the significance of this in terms of mindfulness?

The ancients believed that emotions reside in the body. This comes up a lot in serious yoga classes.

This highly innovative study shows that the control of the adrenal medulla – the main effector of the stress response – is not from the conscious ruminating thinking centres, but by the motor and sensory cortex.

This explains why breathing, as well as yoga and Tai-Chi, are an important part of meditative practice. In my experience, these kind of interventions do affect the stress response in a beneficial way.

Mindful exercise exists in many form. For example, weightlifters need to be very mindful to maintain perfect form. Cycling is another example: it is vital to concentrate on every pedal stroke and maintain an even cadence. Once you start to day dream, you notice straight away that your output is way worse. This overlaps with the concept of flow. It is about getting in the zone. There is a very inspiring TED talk by Judson Brewer MD, Ph.D. that explains the physiology behind flow and how it is augmented by mindfulness. Mindfulness is work, and it does require discipline. There is a paradox here of non-striving and non-doing while also being disciplined.

You are a sleep medicine expert. Could you comment on the relationship between mindfulness and sleep?

Insomnia is a complex problem with many causes. However, for most people with idiopathic insomnia, the cause is these self-referential recursive ruminations. They aren’t able to “turn their brain off”. Through mindfulness practice, they are generally able to tame the default mode network that’s responsible for ruminating and daydreaming. A simple strategy would be to lie in bed and concentrate on the breath. This would ease the transition between wakefulness and sleep.

mindfulness default mode network neurological basis for the self

Mindfulness is a mainstay treatment for many mental health disorders. What about use of mindfulness in the treatment for organic pathology of the brain usually treated by neurologists?

There is some preliminary data that mindfulness training has a beneficial effect of seizure frequency in patients with epilepsy. It is a medical condition associated with tremendous anxiety and stress, so mindfulness could have a significant benefit in more than one way. It may even have a benefit it terms of remembering to take medication on time, etc.

Some robust studies show that the frequency of relapse in multiple sclerosis decreases with mindfulness intervention. The effect from mindfulness is similar in magnitude to the effect from beta-interferon. 

John Kabat-Zinn used to take the patients who suffered from chronic pain or had diseases for which we had no answer, and those patients got better. Even beyond neurology, there is some evidence that mindfulness can have benefits in psoriasis. We are probably only at the bottom of this mountain.

Dr McBurney has given me so much to think about. I will follow up with part 2 of our discussion that focuses more on the philosophical and life experience aspects of mindfulness once I wrap my head around it.

neurological path mindfulness default mode network adrenal medulla

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