To Meditate Perchance to Dream

First the disclosure: this blog is of course about Me.

But it’s also about You. And yours. Because as you know, we’ve become a culture that does not sleep.

Why don’t we sleep? I like to think that it is an evolutionary adaptation; not sleeping, after all, allows us more time for Facebook.

Or Etsy for you makers. Or Amazon for you shoppers. And let’s not forget our middle, high school and college students. Do they even have classrooms anymore, or are lectures all online (on screens)?

One tired pony. By Rachel C from Scotland (Flickr) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons

One tired pony. By Rachel C from Scotland (Flickr) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons

Honestly, the evolutionary adaptation idea comes from how we live and work today. And no, this is not another rant/lecture on the color of light emitted by whatever non-cathode ray tubes are in our phones or tablet-like devices.

It’s just that just working in our very busy online/wired world, jumping from web page to project management software, to big-screens in meetings has us adapted to being  on: capital “O” capital “N”.

This multi-multitasking has grown (for me) a new type of neurons that are not happy unless they are gleaning new information from a screen, all the time. And these neurons don’t stop working when the screen is gone; no, they continue seeking and trying to process. For me, if there’s no screen to look at, the neurons ping-pong around behind my eyeballs, looking and searching, as if to say, “Input missing! Input missing!”

The result can be hours in bed sans sleep; it seems the racket these neurons make keeps all the other neurons up.

There is no point in blaming the screen and software that allows us to get work done; more work, faster and more efficiently. This is life in the 21st century.

Yet we need to sleep. What to do?

Richard Davidson and his group  at UWI-Madison, have been trying to impress on us the answer to What to do? for quite some time. In a study published February 22 in Plos ONE, his team finally has my attention.  The paper is “Short meditation trainings enhance non-REM sleep low-frequency oscillations”.

Brain Waves and Measuring Sleep
In order to understand better the results of this Dentico, et al. paper, let’s talk about brain waves and how sleep can be measured. The three main means of measurement used in sleep research are: EEG (electroencephalogram), used to measure overall brain wave activity; muscle tone is measured by an EMG (electromyogram); eye movement is recorded using an electro-oculogram (EOG). The EEG is important to distinguish the stages of sleep, while the EMG and EOG are used to distinguish rapid eye movement or REM sleep from the other stages.

A very basic sketch of daily brain wave activity goes like this. When awake, most of us have activity composed of alpha and beta waves, with beta waves being the most prevalent during the active part of the day. Beta waves are irregular (called desynchronous) and have the highest frequency and lowest amplitude, reflecting the active learning and thinking that characterizes awake periods.

On the other hand, alpha waves are slower, more regular or synchronous with higher peaks and troughs. Alpha waves are characteristic of periods of relaxation and peacefulness and have been shown to be enhanced by meditation and biofeedback practices.

Then there are gamma waves. Or maybe not. Gamma waves seem to be a contentious issue. Here is some research in support of gamma-type brain oscillations:
In 2004 a study involving 8 long-term meditation practitioners, Tibetan Buddhist monks, had electrodes applied and brain activity monitored during meditation. The brain activity was then compared to that from a group of novice meditation practitioners. The brain activity of the novices was similar to that of the long-term practitioners.

However, when the monks were asked to generate a feeling of compassion during meditation, their brain activity took on a rhythmic and coherent pattern, generally considered as an indication that neuronal structures are firing in harmony. The associated frequency of this coherent brain activity was 25–40Hz, previously shown to be the frequency of gamma wave oscillations.

These gamma oscillations were not observed in novice meditators, though further training of the novices produced strengthened rhythmic signals, suggesting that the ability to produce gamma brain waves can be trained.

Acute Meditation-Sleep Effects
In this Dentico et al. study, 24 long-term meditators, and 24 meditation novices were studied by EEG, to see if neuroplastic changes could be induced acutely by 2 intensive days of meditation practice.

Two different meditation practices were used: 1) a mindfulness-based, and 2) a compassion-based meditation. These practices were implemented in two 8-hour sessions. The group of novice meditators were used to study whether there was a difference in sleep EEG activity between long-term and short-term meditation practitioners.

Previous studies have shown that motor and mental training can induce neuroplastic changes, both during awake and sleep periods. This experience-linked plasticity has been measured as power changes in slow-wave (1–4Hz) to alpha wave bands (8–12Hz) ranges.

Results of this study showed that overall sleep architecture was not significantly impacted by the days of meditation, that is the various sleep cycles were not affected.

There was a significant increase in EEG power, especially in low frequencies (1–12Hz) across sleep cycles after the intensive mindfulness and compassion meditation practices and this low frequency activity had a positive correlation with lifetime meditation practice.

The authors note that they were able to show acute effects of meditation training during subsequent sleep, while commenting that the functional significance of these brain changes will have to be worked out by future studies.

To be clear, sleep was used here to measure changes in brain activity. My interpretation that this study means better sleep through meditation is not directly true. What I’m grasping at is the quieting of the mind and more intense alpha wave activity seen in the results. Twenty-four subjects that were novice meditators slept well enough to participate to the end of this study. That’s good enough sleep for me.

In addition there is this particularly interesting statement in the conclusion of the paper:

“The alpha-gamma interplay is particularly interesting in light of the role of these frequency bands in mediating top-down and bottom-up brain connectivity respectively (41) and suggests that training voluntarily directed attention creates in the long run effortless enhanced cognitive abilities mediated by bottom-up gamma processing (10).”

Friends, think of it:”effortless enhanced cognitive abilities”. Meditation.

You can learn more from the paper:
Dentico D, Ferrarelli F, Riedner BA, Smith R, Zennig C, Lutz A, et al. (2016) Short Meditation Trainings Enhance Non-REM Sleep Low-Frequency Oscillations. PLoS ONE 11(2): e0148961. doi:10.1371/journal.pone.0148961

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Kari Kenefick

Kari has been a science writer/editor for Promega since 1996. Prior to that she enjoyed working in veterinary microbiology/immunology, and has an M.S. in Bacteriology, U of WI-Madison. Favorite topics include infectious disease, inflammation, aging, exercise, nutrition and personality traits. When not writing, she enjoys training her dogs in agility and obedience. About the practice of writing, as we say for cell-based assays, "add-mix-measure".

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