Saturday, March 26, 2011

#8 Fear of becoming an HRVF Junkie

People are frequently surprised by how powerful Heart Rate Variability Feedback (HRVF) can be.  In the words of one client “this is more powerful than any medication I’ve been on…it leaves me really calm, but awake”.  Apparently because of this type of natural, spontaneous  comparison to drugs, people experience fear of becoming addicted or dependent on HRVF.  Wait a second, you mean addicted to breathing? Like drugs?

While this seems absurd I hear it often enough to recognize that it is a common concern which needs to be addressed.

When a person trains with HRVF they are using the feedback to consciously control their breathing, and their autonomic nervous system.  Feeling stressed they consciously decide to use HRVF which changes their physiological and mental state.  Because they have feedback, as opposed to simply deep breathing, their learning is much faster and more efficient.   Like learning piano with a teacher vs. learning from a book with no correction for mistakes.

And like any skill, breathing at your resonant frequency with HRVF becomes more automatic with practice.  And that means that it becomes unconscious.  The more you practice, the less you need the feedback.  The result is that with time when a person becomes stressed, they unconsciously change their breathing and pull themselves back into a relaxed, balanced state without any thought or effort.  Far from being dependent, the person who is trained in this way is much more autonomous.

The road to true independence requires strategic, time-limited dependence on good teachers.  And HRV feedback is a great teacher.

#7 HRV Feedback is not Meditation

People exploring Heart Rate Variability Feedback (HRVF) often come to the incorrect conclusion that HRVF is “just meditation”.  As Llyod Bentsen said to Dan Quayle in the Vice Presidential Debates:  Senator I served with Jack Kennedy… I knew Jack Kennedy… Jack Kennedy was a friend of mine…Senator,  you’re no Jack Kennedy.

Saying that HRVF is “just meditation” short changes both HRVF and meditation.  In the mid 70’s I caught the wave when Maharishi Mahesh Yogi was touring the US and took a course in Transcendental Meditation (TM).  While I have my doubts that the mantra I was given was specifically chosen for me by the Mahrishi as promised, I still use it to this day. I have found TM to be a very useful tool for relaxation, and have practiced it regularly for decades.

The underlying physiology of meditation has been elucidated by the work of Herbert Bensen MD on what he calls the “Relaxation Response”.  The most important effect is an increase in the Parasympathetic (calming) to Sympathetic (arousing) nervous system ratio.    While the ratio is increased, the overall output of the autonomic nervous system is turned down. (There are contradictory findings on this fact which I believe can be explained by the pattern of breathing employed in the meditation.)  This can be demonstrated by meditating while using an HRV device to monitor your heart rate.

Typically what happens when you meditate while monitoring heart rate, is that there is a significant decrease in heart rate variability.  As the parasympathetic/sympathetic ratio increases, the individual relaxes and breathing becomes more shallow.  This causes HRV to decrease. This leads you to a state which is more relaxed, but not particularly “ready”.  It’s great for shutting down your mind before bed, but lousy if you are headed to a party where you want to be vivacious and scintillating. (My goal, not always realized.)

HRVF in contrast leads to a very different physiological and mental state.  While the ratio of Parasympathetic to Sympathetic nervous system output is increased as with meditation, the overall output of the autonomic nervous system is maintained or even increased.  You will see an increase in the variability of the heart rate.  And mentally you will be in a “Relaxed and Ready” state.  It is a fluid state where you can shift to quiet contemplation, or to socially engaged and dynamic.  For that reason it tends to be much more useful during the day when a person needs to get “balanced” before a demanding activity like a presentation.

Understanding the difference between HRVF and meditation illustrates why the picture above is after the big meeting- calming down and digesting the experience with meditation.
(As opposed to preparing for the meeting, when HRVF would be more useful.)

HRVF and meditation both lead to very useful but distinct physiological and mental states.  In an echo of Lloyd Bentsen:  I know meditation…meditation is a friend of mine…but HRVF is not meditation.

For readers interested in a contemporary view of meditation check out:  Buddha’s Brain:  the practical neuroscience of happiness, love and wisdom by Rick Hanson PhD.

Thursday, March 10, 2011

# 6 What is “Coherence” and how does the emWave™ or StressEraser™ measure it ?

Coherence is a tricky concept to master because it is used in several different ways in the literature of HRV.  To facilitate understanding I’ll explain “coherence” from the perspective of someone opening up and beginning to use an emWave/StressEraser.

Auto-coherence of the Heartwave. – Breathing deeply and rhythmically, the display of the heart-rate will be a smooth, regular, undulating wave.  A  “sine-wave”.

Given it’s regularity the parts of the wave are all “organized, consistent, and logical” with each other.  It is coherent with respect to itself, or “auto-coherent”.  The HRV device calculates exactly how regular or “auto-coherent” the waveform is.  This gets represented as low (red on the emWave, one box on the StressEraser), medium (blue/two boxes) or high (green/three boxes) “Coherence”.  Achieving “High Coherence” (Auto-coherence) means that there is the potential to achieve other types of Coherence that have profound effects on the mind and body. But you’re not there yet.

Physiological Coherence-The body contains many oscillators, that is, systems that cycle.  For example the heart beat, breathing, blood pressure and brain waves. When two or more systems are synchronized they are said to be “coherent”. When many systems in the body are synchronized the person is in a state of “physiological coherence”.  To achieve this state takes ten to twenty minutes for most people beginning to use HRV.  Why?

Imagine a middle school orchestra.  If the conductor  keeps regular time (auto-coherence) then as the orchestra continues to play, the instruments will fall into synch.  The drums get in synch with the conductor which helps the bass get in synch  which helps the strings get into synch etc. until the entire orchestra is synchronized or “coherent”.

In the body, the heart and respiration get in synch which then allows the pressure sensitive baro-receptors to get in synch which then allows the brain (thalamus and cortex) to get in synch.  This is a sequential process that occurs over time.

Individual Coherence- After Physiological coherence has been achieved it is possible to see the manifestations at the behavioral level.  The person is more “coherent” –e.g. ideas are expressed more clearly, actions are more fluid and take less energy, and life in general proceeds more smoothly.

Take Home Point. – When you start to score “High Coherence” in an HRV session your mind-body is not yet in a state of “Coherence”.   If you continue to score “High Coherence” and allow the different “players” in your body to sequentially get in synch over ten to twenty minutes you will then be in the “Coherent” state.  And you will know that not because of a score, but rather because of how you feel.

Tuesday, March 1, 2011

#5 How does the StressEraser or the emWave measure the function of the Sympathetic and Parasympathetic Nervous Systems?

How does the Stress Eraser or the emWave measure the function of the Sympathetic and Parasympathetic Nervous Systems? Short Answer: It doesn’t. (Not directly.)

The Stress Eraser and the emWave are the Heart Rate Variability (HRV) Feedback devices currently available on the consumer level. I’m generally a big fan of the user reviews on Amazon, however with these devices there is a lot of confusion. Consider the following excerpt from a retired physician:

“based on the “feedback” it gives the user, I really don’t understand what it is measuring. It simply can’t be sensitive enough to detect what it purports to detect without being very much more complex than it is.”

The Stress Easer and emWave measure one thing, and one thing only- the inter-beat interval. That is, the time between heart beats. With this one measure it is possible to calculate the heart rate which is constantly changing. For example if the inter-beat interval is 10 seconds the heart rate is 6 beats per minute. If the next interval is 15 seconds the rate has dropped to 4 beats per minute. (Unrealistic numbers chosen to simplify the math.) So how does it measure the output of the Autonomic Nervous System (ANS)?

The devices don’t measure directly the output of the ANS. Using the inter-beat interval data, and the mathematical technique of Fast Fourier Transform, the rate of change of the heart rate is calculated, on the fly, in real time. This is the “magic” of the technology.

Sometimes the heart rate is changing quickly, and sometimes slowly.

Fast changes in rate are caused by shifts in parasympathetic tone (by opening an ion channel which is virtually instantaneous).

Slow changes in rate are caused by shifts in sympathetic tone (linked by a second messenger system which is relatively slow taking roughly 4 seconds to change the rate).

So the rate of change of the heart rate, fast or slow, is a fairly accurate reflection of the activity of the ANS (particularly the parasympathetic system), even though it is not measured directly.

Next time we’ll look at “coherence” and see how that is measured (or not).