REPORT:Galvanic Skin Response & Breathing

May 15, 2005 (Revision 1.1, May 18, 2005)

SPECIAL REPORT: Galvanic Skin Response - A Window Into Breathing and Autonomic Nervous System Function

By: Stephen Elliott

COHERENCE(tm) asserts the theory that there is an approximate 12 second fundamental autonomic nervous system rhythm at which the adult cardiopulmonary system, inclusive of nervous system aspects, aspires to operate while in the state of rest or semi-activity - that this rhythm results in cardiopulmonary resonance and is an outcome of fine autonomic nervous system balance. It is further stated in The Science section of this website that this rhythm, consisting of a sympathetic phase and a parasympathetic phase, pervades the entire body resulting in the cyclic activation and deactivation of body systems including cardiac rate, arterial pressure, lung bronchi, low threshold muscle motor units, etc. This rhythm is depicted in FIGURE 1 below.

FIGURE 1: 12 Second "Fundamental Quiescent Rhythm"

Galvanometric Skin Response (GSR) measures changes in skin conductivity as a function of autonomic nervous system changes, specifically the sympathetic branch. This "conductivity" or the reverse thereof, "resistivity", is measured in "ohms". Generally speaking, increased sympathetic emphasis results in increased conductivity, i.e. lower resistance, and decreased emphasis results in decreased conductivity, ergo higher resistance. It stands to reason that if the above assertions are correct, then GSR could be employed to assess sympathetic nervous system changes as a function of breathing frequency and to detect the presence of The Fundamental Quiescent Rhythm in action.

Assessment of dynamic GSR requires the use of a proper ohm meter along with adequate transducers for coupling the meter to the body. Due to a high degree of innervation in the hands, GSR is best measured by wrapping the hands around large cylindrical metallic electrodes. While the relationship between breathing and skin response can be "detected" with a top-end analog GSR meter, a high performance digital meter is required to measure, characterize, and record the dynamic relationship between GSR and breathing. In this case, an Agilent 34401A Multimeter is employed. All measurements are performed at the rate of 5 per second plotting 300 points per minute. Therefore the graphs are quite precise relative to dynamic GSR activity. Also, relative to measurements depicted in FIGUREs 2-4, a "solo" electrode is employed. This allows GSR measurements to be taken via one hand vs. both hands.

FIGURE 2 depicts a measured instance of the relationship between breathing frequency and galvanic skin response. It depicts three consecutive 3 minute breathing periods. During the first period, the subject is breathing at the rate of 5 cycles per minute. At the end of 3 minutes, the subject abruptly shifts to the rate of 15 cycles per minute. At the end of 6 minutes, the subject again abruptly shifts to 5 cycles per minute.

FIGURE 2: GSR vs. Breathing Frequency

Here it can be seen that during the first 3 minutes, while breathing at the rate of 5 breaths per minute, GSR averages 60K (60,000) ohms. The moment the breathing frequency switches to 15 breaths per minute, there is a sharp drop in skin resistance of ~14K ohms. At the end of 6 minutes, when the breathing frequency of 5 cycles per minute resumes, resistance once again drops for a period of about 30 seconds and then begins to increase somewhat gradually. At the end of 9 minutes, the GSR value is >52K ohms and climbing.

It is generally true that when there is a significant change in breathing frequency in either direction, there is temporary shift in sympathetic emphasis until the body adapts to the new frequency. It is also true that as breathing frequency shifts from a lower frequency to higher frequency, there is a sharp and immediate increase in GSR conductance, indicative of a prompt increase in sympathetic emphasis. When breathing frequency shifts from a higher frequency to a lower frequency, there is a temporary increase in sympathetic emphasis followed by a gradual decrease in conductance as the body adapts to the lower frequency. This response to higher and lower frequencies makes sense in light of the requirement for rapid acceleration of motion in the case of "fight or flight" followed by gradual deceleration once the urgency is passed.

Under the proper conditions, primarily involving time of day, these results can be repeated with a high degree of consistency and correlate well with changes observed in heart rate variability as reflected in The Science section.

FIGURE 3: GSR While Breathing At 5 Cycles Per Minute

Now, can The Fundamental Quiescent Rhythm(tm) be detected and characterized via galvanic skin response? FIGURE 3, which characterizes GSR over a period of 3 minutes while breathing at 5 breaths per minute is typical of the result. Measured from peak-peak the majority of intervals are clearly approximately divisible by 6 seconds. Assessment of GSR while breathing at 5 cycles per minute was performed many times during the course of the investigation with essentially the same result. FIGURE 3 demonstrates the existence of a clear 6 second rhythm but is the waveshape as anticipated?

FIGURE 4: Spontaneous GSR While "Breathing Small"

If FIGURE 3 is what the GSR looks like while "breathing big", i.e. breathing with depth at the rate of 5 cycles per minute, what does it look like while "breathing small"? That is, if the respiratory stimulus is removed by adopting a very shallow breathing pattern, will this allow the baseline GSR to be seen with minimal respiratory sinus arrhythmia influence? The surprising result, depicted in FIGURE 4, is the initial 36.4 seconds of the measurement session immediately following that of FIGURE 3. During this 36 second period, the GSR rhythm also has an unmistakable 6 second orientation! The fascinating thing is that this pattern was generated by the autonomic nervous system in what amounts to the absence of a stimulating respiratory rhythm. Is this a result of resonance, entrainment, or both?

These points will be discussed in an upcoming revision.

Thank you for your interest.

	COHERENCE L.L.C., based in Allen, Texas, is owned and operated by Stephen Elliott. Stephen is a long term practitioner of Eastern yogic and martial arts and an avid researcher in contemporary biofeedback. Professionally, Stephen is an engineering executive, inventor, and techno-business strategist in the technology sector.

Products and methods described herein are protected by multiple U.S. and Canada patents pending.

COHERENCE(TM), Coherent Breathing(TM), Breathing Pacemaker(TM), The New Science of Breath(TM), What Was Lost Is Not A Chord But a Rhythm(TM) are trademarks of COHERENCE L.L.C., Allen, Texas, U.S.A.

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