Controlled Breathing: a bridge from the I-function to the unconscious?

Darlene Forde's picture

In this course, I have become intrigued by cultural attempts to access and control the “unconscious” parts of the nervous system. Non-western cultures have established methods which allow (or purport to allow) untraditional connections to be made in the nervous system, methods which allow the practitioner to transcend ordinary levels of consciousness and reach higher states of consciousness (i.e. meditation, yoga, Buteyo, martial arts). On a physiological level, we can say that masters of these arts may possess the ability to make direct connections between the part of the neocortex we call the I-function and the autonomic division of the nervous system—the unconscious. These methods violate many of the neuronal networks and associations that we expect in the nervous system. For example, it is difficult for me to imagine that I might directly control the movements of my small intestine. How could a neuronal network be established that might run from my I-function to the motor neurons in my small intestine in the encouraging it to contract shortly after a meal? Whether the direction is direct—a neurons pathway leading directly from my neocortex to the motor neurons in the smooth muscle—or indirect—a neuronal path that takes a bridge between neighboring “counties” of the nervous system—is irrelevant as long as these pathways or roads can be maintained and utilized consistently and without difficulty.

Controlled and ‘conscious’ breathing is a commonality shared across various cultural attempts to reach higher levels of consciousness and optimum health. Indeed, breathe work is a focus on such disparate disciplines as Tai Chi, various martial arts, meditation and yoga. In his audiobook Breathing: the master key to self-healing, Dr. Andrew Weil argues that proper breathing is the most important practice of a healthy lifestyle. (1) Accepting that proper breathing can contribute to optimum health is not a difficult argument to accept. More controversial (at least to me) is Weil’s assertion that breathwork has the potential to influence and reprogram the nervous system. Breathwork can achieve this aim, he argues, because it serves as a link between the conscious and unconscious mind (i.e. communication between the I-function and the rest of the nervous system), serving as a doorway to control of the autonomic nervous system. Furthermore, he states that it possesses the ability to reduce stress and control anxiety and regulating mental states.

Weil arrived at these conclusions from his long time practice and study of yoga and pranayama (prana 'vital energy' + yama 'self-control')—a controlled breathing regimen designed to maintain and control the body’s vital energy. They were reinforced by his experiences working with an osteopathic physician who sought to improve patients’ breathe through physical manipulation of the body. The osteopath’s success with patients encouraged Weil to consider incorporating breath exercises as part of treatment regimen for his own patients. Breathwork was the single recommended technique for which he received the most positive feedback; his patients credit it with improving digestion, addressing panic disorder and anxiety, improving circulation, and improving irregular heartbeats. (1) Other physicians and medical bodies have also found breath training to be beneficial. For example, the American College of Chest Physicians (ACCP) offer evidence that breath retraining can be beneficial for individuals with asthma and hypocapnia—a deficiency of the carbon dioxide in the blood caused by hyperventilation that can lead to high blood pH or alkalosis. (8) Similarly, researchers at Semel Institute for Neuroscience and Human Behavior at the University of California have found breath to be useful in improving psychological, emotional and biological processes in depressed individuals. (12)

Weil’s first and second premises for the use of breathwork require further investigation and explanation. Breathing is an activity can be controlled by the autonomic nervous system—that is by neurons that are not under conscious control—and consciously by neurons under conscious control, a part of the nervous system that we call the I-function. Weil avoids an extensive or more scientific explanation for this phenomenon, focusing his efforts on presenting his eight breathing exercises to the public rather than presenting rigorous scientific evidence for the mechanism by which it occurs. This is unsurprising as most audiobook listeners are likely uninterested in the cellular and molecular components behind the bridging of the I-function to the autonomic nervous system.

Other proponents of breathwork such as AMSA, Gay Hendricks, Dinamika—a company that produces medical instruments designed to improve breathing capacity—emphasize controlled deep-breathing’s ability to reduce sensations of stress and tension. (2) (3) (4) When the body is under chronic stress, it responds with restricted rapid shallow breaths that sit in the chest. The range of motion in the connective and muscular tissue of the chest wall becomes restricted. The sympathetic division of the autonomic nervous system increases levels of adrenaline in the bloodstream; heart rate increases and digestion slows. In shallow breathing blood flow is concentrated in the lower lobes of the lung—areas that have a limited space for expansion—resulting in lower rates of oxygen transfer to the blood and nutrient distribution in tissues. (3) Contrastingly, in normal or relaxed states the parasympathetic system effects are more evident. Digestion resumes. Breathing is more relaxed and can be observed in the stomach (“diaphragmatic breathing”) rather than in the chest. Both Hendrick and AMSA imply that by consciously controlling breathing, stress can be reduced and parasympathetic influences invoked. Furthermore, they imply this benefit can be maintained through training. Conversely, the effects of poor breathing can lead to negative influences on health.

Such arguments and rationalizations are at best vague. While they demonstrate an association or connection between these phenomena they fail to provide a definitive causal mechanistic link between breathwork and these processes. Yet the failure to more explicitly describe the mechanism at work is not the fault of these breathwork advocates. A hunt of the scientific literature demonstrates that while breath manipulation can lead to decreased blood pressure and increased parasympathetic activity, the mechanism by which this interaction takes place is not fully understood.(4) As recently as 2005 CHEST, the journal of the ACCOP admits that the mechanisms by which breath exercises has an effect is unknown. (8) (10) Because breathwork is free and—with the exception of certain more complex pranayana breathing techniques such as the ones incorporating alternate nostril breathing—relatively safe, there has been no great sense of urgency for researchers to focus their attention on the impact of breathing on the nervous system. Most clinical research attempts on the effects of breathwork on the nervous system in recent years have focused on the effects of pranayama or yoga specifically.

Despite this gap in knowledge, more precise mechanisms have been proposed. Researchers at the Augusta Medical Center in Georgia offer an attractive theoretical model for explaining how breath manipulation may induce a physiological response in the nervous system. (13) They hypothesize that voluntary slow deep breath can reset the autonomic nervous system by triggering stretch-induced inhibitory signals in slowly adapting stress receptors (SARs). Slowly adapting stress receptors can be found in the sensory and motor neurons in the chest. The activation of these stress SARs may lead to hyper-polarization in the nerve cells of the autonomic nervous system which are then propagated through both nerve and non-nerve cells. Hyper-polarization is a negative shift in a cells resting potential that makes it more polarized. This simultaneous hyper-polarization may serve to synchronize nerve and motor cells associated with the heart, lungs, limbic system and cortex, by turning the voltage difference across the membrane down, in essence reprogramming the nervous system. During normal inspiration, stretching of lung tissue produces inhibitory signals by action of slowly adapting stretch receptors (SARs) and hyperpolarization current by action of fibroblasts—a type of connective tissue cell that secretes protein ingredient in the extracellular fibers. Both inhibitory impulses and hyperpolarization current are known to synchronize neural elements leading to the modulation of the nervous system and decrease metabolic activity indicative of the parasympathetic state.

In this manner Weil may be correct in describing controlled breathing as a bridge between the I-function and the rest of the nervous system. Simultaneous hyper-polarization implicated here could allow for the establishment of a new central pattern across the nervous system. Repeated use may be incorporated into the central pattern generator and allow for the incorporation of more healthy and beneficial actions. However, many more studies need to be done to explain this mechanism. Part of the difficulty for researchers is the complexity of breathing in humans. It may prove more beneficial to study controlled breathing in non-human organisms with simpler nervous systems. The work of researchers such as the Nobel prize winning Eric Kandel—who helped to elucidate the process of long term memory with his work on the simple sea slug Aplysia—has demonstrated that sometimes the most complex mechanisms can be more easily revealed in simpler organisms.



(1) Weil, Andrew. Breathing: The Master Key to Self Healing (Sounds True, 1999)

(2) Hendricks, Gay. Conscious Breathing. (New York: Bantam, 1995)

(3), American Medical Students Association

(4) ,

(5) Gogoi, Nilutpal. "Breathing: An Ideal Marriage of the Nervous and Respiratory Systems." EzineArticles 28 August 2006. 09 May 2007 <>.


(7) Lewis, Dennis. The Tao of Natural Breathing: for health, well-being and inner growth. (San Francisco: Mountain Wind Publishing. 1997)

(8) Bruton, Anne and Stephen T. Holgate. “Hypocapnia and Asthma: A Mechanism for Breathing Retraining?” Chest 2005; 127;1808-1811

(9) Innes, Kim E. and Heather K. Vincent. “The Influence of Yoga-Based Programs on Risk Profiles in Adults with Type 2 Diabetes Mellitus: A Systematic Review” eCam. December 11, 2006

(10) Innes, Kim and Cheryl Bourguignon and Ann Gill Taylor. “Risk Indices Associated with the Insulin Resistance Syndrome, Cardiovascular Disease, and Possible Protection with Yoga: A Systematic Review”. Journal of the American Board of Family Medicine. 2005;18:491-519

(11) “Early Psychedelic Investigators Reflect on the Psychological and Social Implications of their Research. Journal of Humanistic Psychology.2006;46; 432

(12) Shapiro, David, Ian A. Cook and Dmitry M Davydov and Cristina Ottaviani and Andrew F Leuchter and Michelle Abrams. “Yoga as a Complementary Treatment of Depression: Effects of Traits and Moods on Treatment Outcome.” eCAM 2007 April 11,2007

(13) Jerath, R. and J. Edry and V. Barnes and V. Jerath “Physiology of long pranayamic breathing: Neural respiratory elements may provide a mechanism that explains how slow deep breathing shifts the autonomic nervous system.” Medical Hypotheses 67;3; p.566-571




Jon U Cash's picture

Breath control

I've done a lot of meditation and yoga, and I find it fascinating to read about the actual neurological effects of meditative practice (though I wish I better understood the mechanics of it all). Breath control practices undoubtedly have some benefit, and I can't wait for scientific inquiry to reveal just how this works. I think it's likely there are simpler processes (as with the sea slug) that will reveal some insight.

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