The Whys and Whats of Clinical Meditation: Alpha Rhythms, Mindfulness, and Body Sense

We’ve all heard that meditation is a magic pill of clinical applications:  stress reduction, pain relief, depression relapse prevention, etc, and these claims are all backed by solid academic study.  However, these studies typically approach meditation from a cognitive/emotional context, looking at how meditation affects emotions and thoughts.

A new, publicly available study, headed by Dr. Cathy Kerr of Brown University, took a different approach.  Dr. Kerr has charged herself with the task of shifting popular clinical perception of meditation from a cognitive/emotional therapy to a sensory/cognitive intervention.

(The study also contains many great references; I highly encourage you to check it out).

What does this mean?  Dr. Kerr believes that meditation, with its roots in mindfulness, is inextricably linked with the body; that the fundamental role of mindful meditative practices is to change the way you relate to and experience your senses.  The emotional component is a downstream effect of this.

Back in 2011, Dr. Kerr published a study that laid the groundwork for her current effort.  What she found was that people who had undergone an 8-week course in the industry-standard Mindfulness-Based Stress Reduction (MBSR) were able to more finely control the alpha rhythm present in the hand map of their somatosensory cortex.

There are two main neuroscientific concepts one needs to understand to get what that means.  Those are 1) alpha rhythms and 2) somatosensory cortex.

I’ve linked to their respective wikipedia pages but that might be information overload.  Here’s what you need to know:

Alpha Rhythms:  neurons can communicate extremely fast with one another, capable of sending a signal every 1 millisecond (or a thousand times a second).  However, most don’t operate at full blast all the time.  Neurons operate at varied speeds and these different speeds seem to help the brain do different things.  These speeds are also called “neuronal oscillations” or “neuronal rhythms.”  An alpha rhythm is just a pattern of neurons firing at about 7-12 Hz, or times per second.

So if you have a metronome and set it to 600 bpm, THAT is how fast these neurons are firing (and alpha is on the slower side of the spectrum).

Alpha rhythms have long been associated with wakeful relaxation and closed eyes and practitioners of meditation tend to create stronger alpha waves.  More recently, however, alpha waves have been interpreted as having a role in inhibiting parts of the cortex that aren’t in use, participating with other types of neuronal rhythms (beta and gamma) in attention and consciousness

Somatosensory Cortex:  this is an area of the brain that is responsible for feeling your body (somato = body; sensory = feeling; somatosensory = body-feeling).  It’s primary location is in a place called the postcentral gyrus.

English: Postcentral gyrus in the human brain.

This strip of brain is amazing.  Why is it amazing?  Because not only does it represent all the feeling you have in your body, but it does so in an organized way such that there is the hand area of the somatosensory cortex, the lip area, the foot area, the eye area, and a region of neurons that correspond to each part of the body.  However, different parts of the body are more important for touching things than other parts of the body, so some parts have more neurons representing them and are therefore more sensitive.  Remarkably, the pattern is the same across people and looks like this:

English: Author: btarski Date: 6/23/06

English: Author: btarski Date: 6/23/06 (Photo credit: Wikipedia)

The parts of the body are drawn to scale to represent how big of an area they have in the brain.  As you can see, the hands, lips, and tongue have very large sections devoted to them, helping to explain why they’re so sensitive.

So, bringing all this back to the 2011 study, we now know that (to grossly paraphrase) meditation practitioners can more finely control  attention on certain parts of their body.

That’s fascinating and all, but why would close, focused attention to sensations of body and breath lead to a lower rate of depression relapse?  Or of better chronic pain management?

That’s where Dr Kerr’s new study comes in.  In her 2013 article, she argues that mindfulness is less a thought exercise and more of a way to change one’s perceptual processing, meaning the main effect of mindfulness isn’t from thinking but from feeling one’s body.   This is not a normative view in the current cognitive academic landscape.  Participants practiced shifting attention to different body parts (or not; in science, a control group is absolutely critical).  It was found that meditators were better, compared to nonmeditators, at exercising fine control over alpha rhythm in the corresponding parts of the somatosensory map that represents those body parts.

So, just by shifting attention to your hand changes the excitability of neurons in the brain’s map of the hand! Pretty cool!  But, Dr. Kerr discusses larger implications of this finding in the context of her proposed theory (listen to her discussion on the Secular Buddhist Podcast here).

People who experience chronic pain develop a bias toward the pain sensation–a loss of freedom of attention.  They become always on the lookout for that pain signal, and because they’re tuned in to the pain signal, they tune other things out.  What Dr. Kerr believes is that meditation can de-bias them from the pain sensation.  It can reestablish equanimity and attentional control.  It is important to note that mindful chronic pain management does not decrease the pain intensity but seems to decrease reactive suffering to the pain:  the same pain is there but you care about it less.

It’s like playing a game of I-Spy.  In this game, you’re playing with your brain.  Your brain tells you “I spy something painful…” and then you look for anything painful while not focusing on everything that’s not painful.  In chronic pain cases, your brain is playing this game constantly.  You get really good at quickly finding pain, to the detriment of finding other things.  Mindfulness helps you to stop playing “I-Spy…” and to start choosing what you are looking for.

On the other hand, what about ailments that are not physically rooted like pain, but mentally rooted, like depression?

The ability to focus on thoughts or memories is directly related to one’s ability to control sensory volume.  You need to be able to turn down volume on sensory signals in order to be able to work effectively with thoughts (and vice versa).  The tool the brain uses to do this is alpha modulation.

Negative processing is maintained by rumination on negative thoughts.  This internal processing directly competes with alpha modulation attentional processes.  If one can learn to modulate sensory alpha (really feeling one’s hand, or breath), one learns to turn down the volume on rumination

In the end, the clinical benefits of mindfulness comes to the idea of attentional control.  By practicing intentional control of attention, directing it at different parts of the body, one learns a new way to experience sensory signals and becomes better at managing selective attention.  In the brain, this is largely controlled by the alpha wave.  Control of this alpha wave, and control of attention, are ways to break negative mental habits, such as constantly attending to pain or ruminating on negative thoughts.

It comes down not the reality we live in but the world which we choose to perceive.


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