While I was looking for an old article on the oculocardiac reflex, I stumbled on this small goldmine, from ReVision magazine in 1994: The Internal Mystery Plays: the Role and Physiology of the Visual System in Contemplative Practices. They (Questia) have a 72-hour free trial, so I used that to copy-and-paste the contents of that paper into a Word document. Man, I love the Internet!
[T]he foundations for all mystical experiences can be found in various aspects of the near-death reflex, which is the ultimate reflex of the “fight-or-flight” mechanism of the autonomic nervous system for fear and stress responses….
The eye has long been held in high regard as a mysterious organ and, therefore, has been associated with the secret mysteries of all the world religions for over five thousand years. The sense of sight was considered more excellent than all the rest of the senses because it did not depend upon contact with or close proximity to the object….
The eye was also considered analogous to the chemical mercury as the catalyst for transformational change…. This is due to the reflection seen of one’s self when looking in the eye of another, similar to the reflection of oneself when looking at a small ball of mercury. This is representative of the transformational process in the psyche….
Since the transformational process is the equivalent of a “rebirth,” the pupil of the eye as a metaphor for the rebirth of the soul has also been associated with the yoni of the Hindu religion. The analogy is made to the birth into this life through the yoni of the female, while birth into the afterlife passes through the opening of the “Inner” eye….
What [Wilder] Penfield found was that stimulation of the right temporal lobe in the area of the anterior Sylvian fissure led to typical, reproducible images of neardeath states, angels, the Virgin Mary, and other archetypal forms of images with significant physiological and theological aspects attached to them….
[W]hen there is an excessive stimulation of the parasympathetic nervous system, which can also occur in darkness, a vasodilation of the peripheral circulatory system occurs, leading to a slow decrease in blood flow to the cerebral cortex. When this occurs, the areas most sensitive to decreased blood flow and decreased oxygenation are those areas called “watershed” areas at the end of capillary beds. These areas occur where the capillary beds of one major artery comes in contact with the capillary beds of another artery, such as those seen in the occipital lobe and brainstem. The occipital pole, which serves central visual acuity, is one of the most common areas involved in cerebral vascular accidents of the watershed type. Typical to loss of blood flow to this area leads to a condition known as a cortical release phenomenon … with the generation of a large, white light in the central portion of the vision…. As this white light extends, it increases to involve the entire occipital cortex and, thus, the entire visual field.
This is what occurs in profound mystical states such as those seen in Zen Buddhism and Hinduism, where profound relaxation (i.e., parasympathetic overload) occurs with marked peripheral vasodilation … leading to cortical ischemia of the type described above. This has also been called “Nirvana,” “Samadhi,” or “Union With God”…. Also, the sudden loss of blood pressure to the brain that elicits this phenomenon is basic to the neardeath experience and the commonality of vascular collapse seen in those patients….
[W]hen [the over-stimulation of the sympathetic arc] occurs in certain physiological states, such as in meditations or while lying horizontally with a vascular collapse, then the stimulus can be prolonged and, in some cases, remembered, thus leading to reports of neardeath states, vision of angels, dancing with elves, or other “hallucinations.” The remembering of these states is enhanced through meditation by a purposeful increase in parasympathetic tone for relaxation to counter the physiologically and physically painful stimuli that increasingly drive the sympathetic nervous system and these images. Hence, in eliciting trance and near-death states, the advanced meditators may be causing ischemia to these vital cortical areas, with possible permanent damage. These damaged neurons will become supersensitive and, thus, enhance the reflex when reelicited….
Why do these reflexes cause people to feel as if they are “suffused with light” as the White Light experience is occurring? This, I think, can be explained by the various physiological aspects that are occurring at the same time as the White Light experience. When this light occurs, there is a profound and sudden decrease in peripheral vascular resistance due to the excessive parasympathetic stimulus (Jevning 1978). This sudden release in vascular resistance will cause a very rapid increase in blood flow throughout the entire body, beginning centrally and moving to the extremities. This gives a sensation of energy, or “light,” being transmitted through the body. Along with this decrease in peripheral vascular resistance there is also a profound relaxation of the skeletal muscles due to this parasympathetic stimulus, which also adds to the feeling of “something” flowing through the body. After years of practice, members of certain Buddhist sects can raise their skin temperature through this mechanism (Benson 1982), showing one instance of where conscious mind can control autonomic functions….
[A]s the White Light develops, blood is being shunted away from the occipital lobe, thus enhancing the White Light and simultaneously increasing blood flow to the extremities in such a rapid fashion that an actual tactile sensation of “energy” flowing through the body is realized. This is also accompanied by a profound release of B-endorphins and other neuropeptides that will induce an “ecstatic” state. This profound parasympathetic state also leads to marked relaxation of the entire body, a state which can only be achieved in deep sleep, Stage IV anesthesia, death, or certain contemplative states….
After the blood has drained from the cortex [in the neardeath experience], the remaining circulatory pressure is shunted into the circulation of the basilar artery, providing circulation to certain areas of the cortex as a result of evolution’s extension into those areas that are related to the persistence of visual, auditory, and memory functions during the near-death state….
During darkness, the visual association areas of the brain, and specifically the occipital and temporal lobes, become supersensitive during visual deprivation. After approximately thirty minutes of total dark adaptation, both the retina of the eye and the occipital cortex of the brain begin having spontaneous discharges of activity due to a lack of external stimulation, which are seen as various lights, phosphenes, and visual phenomena [e.g., form constants] that can be perceived and characterized verbally….
One aspect of eye closure for contemplative practices that is sometimes mentioned, but that I feel is underemphasized, is that of bringing the eyes in convergence (i.e., “crossing your eyes” or looking at your nose) during these exercises, which drives the meditative process to a more rapid induction into the trance state and is usually described as looking at the “third eye” (Rouselle 1960). This occurs through a neurological mechanism known as the “oculo-cardiac reflex” (Duane and Jaeger 1990). This reflex occurs when the muscles surrounding the eyeballs are placed in tension or there is pressure placed on the globes, and this stimulates the parasympathetic nervous system through the vagus nerve to slow the heart rate (Arnold et al. 1991). This reflex is commonly seen in eye surgery when the extra-ocular muscles are stimulated. It is exactly these two muscles, the medial recti muscles, that are over-stimulated in crossing the eyes, and this is mediated through the parasympathetic nervous system (Miller 1985).
Thus, crossing the eyes is not only a result of stimulation of the parasympathetic nervous system but of itself will further stimulate the parasympathetic nervous system to slow the heart rate. Forcibly crossing the eyes through closed eyelids while meditating will stimulate this reflex to its maximum and thus facilitate the stimulation of the parasympathetic nervous system….
The temperature that the body experiences can lead to profound states of mystical experience when brought to an extreme, as seen in hyperthermia and hypothermia (Fay 1959). Cold has played an important role in the internal mysteries in that many of the ancient practices included the placing of the initiate in a cold environment, such as in the underground pits of Eleusis, in caves or on mountain tops, as practiced in the Himalayas. Excessive cold will cause a decrease in the temperature of the anterior hypothalamus, causing a secondary sympathetic stimulation and vasoconstriction of the peripheral blood vessels to preserve body heat. Thus, this decrease in body temperature can add to the overall sympathetic stimulus, inducing the reflex parasympathetic response and increasing its effect on the imaging process….
Similar to visualization is the aural isolation that occurs with these practices in the form of chanting (Glueck and Stoebel 1984) or rhythmic sounds, such as shamanic drumming. These monotonous sounds isolate the hearing to also allow cortical release phenomena of sound. As the trance reaction develops, it is common to have a “rushing sound” in the ears (Harner 1972), similar to the sound of the ocean, preceding the sound of a “tinkling of bells.” This is followed by musical arrays that are unique and sometimes cacophonous, sounding very much like a Buddhist band. It has been shown through electroencephalographic tracings that these monotonous sounds, when given to naive subjects over extended periods of time (i.e., greater than fifteen minutes), can induce marked theta synchronicity across the cerebral cortex (Maxfield 1991), which is the hallmark of meditative state of mind (Kasamatsu and Hiri 1969)….
In these isolated states of mind, including sleep, meditation, and panic situations, the gain of the parasympathetic nervous system is increased to help pick up more information about the potential threat and to facilitate the spread of that information to more areas of the brain for interpretation. It is during these states of isolation that the lower brainstem centers take over because there is no cortical sensory input coming into the system, that is, normal vision and hearing.
This amplifying gain in the sympathetic nervous system increases and takes any information obtained, applying it to its memories through a temporal spreading of information that allows the brain to act as a comparitor (Livingstone 1988; McClurkin et al. 1991), so that, when someone is in a meditative trance while listening to shamanic drumming that is beating at a constant rate, after a period of ten to fifteen minutes or sometimes sooner, many overtones are heard due to increasingly finer discrimination attempts by the brain to identify differences from one tone to the next. Occasionally, this leads to perceptions of hearing songs or voices and, more commonly, changes in tempo (Maxfield 1991).
Likewise, in the visual system, the phosphenes that are spontaneously generated within the retina due to dark adaptation, micro-saccades, and other forms of retinal stimulation, get multiply integrated by numerous areas to try to interpret the shapes it is perceiving (Livingstone 1988)….
Rebirthing and holotropic breathing both utilize hyperventilation techniques to induce first a trance state and, eventually, near-death states. With hyperventilation, there is decrease in the amount of carbon dioxide going to the brain, which acts as a chemoreceptor messenger to decrease bloodflow to the brain to allow carbon dioxide to increase to normal levels. However, after only a few minutes of hyperventilation, there is a paradoxical stabilization of the lowered carbon dioxide levels that is maintained even with normal breathing. Hyperventilation is well known to induce both theta (Kellaway 1979) and delta (Kooi et al. 1964) waves, which are associated with meditative states….
[I]n severe fasting, as hypoglycemia occurs in the brain, there is a sense of ensuing death; this fear of death alone can have sufficient sympathetic stimulation to stimulate the survival-maintaining images of the right temporal lobe….
Other forms of ascetic practices, such as mutilation and sacrifice, have similar reflex stimulation to the sympathetic nervous system. Any painful stimulation on the body surface usually evokes a vasopressor response in the body through the vasomotor areas in the medulla; thus, the pain of these practices will increase sympathetic stimulation and become additive to any other sympathetic stimuli occurring simultaneously in the body.
With contemplative practices, a balance of these parasympathetic states are consciously waged against the sympathetic stimuli that are entering the physical body. The goal of such practices is to maintain a high state of alertness while simultaneously maintaining as much relaxation as possible in response to the stimuli, such that the sympathetic nervous system and parasympathetic nervous system are both simultaneously and maximally stimulated. With experience, the practitioner of these rituals will gain the ability to withstand extremes of stress to the physical body, psyche, and spirit through the control of these stressors, while developing relaxation techniques to reach altered states of consciousness. So as this balance is upset, the increase in the parasympathetic nervous system tone will lead to increasing levels of controlled cerebral ischemia, leading to the visual imagery and various Light experiences….
Many of these conditions are related to actual stresses on the physical body or perceived threats to the physical body. Physical stress, such as that seen in the Ghost Dance of the North American Indians, or the psychological stress of knowing that one is about to die, can be of sufficient magnitude to stimulate the appropriate reflexes and begin the cascade of events that leads to a near-death experience and the ability to elicit the aid of the entities of the “other world” (Eliade 1958; Walsh 1990). This is the key to the mystical process and to the rebirth of the soul and the individual.
Over many years of meditative practice the great healers have been able to heighten their sensitivities to the point of reaching levels of autonomic quietude, with maximal gain of the sympathetic system, such that the brain feels that the only other state it remembers and identifies with is near-death state. It is at this point of meditative practice that the adept has the spontaneous near-death experience due to the paradoxical feeling in consciousness that there is a total disconnection between the sympathetic and the parasympathetic sides of the autonomic nervous system and, therefore, loss of control of the physical body—hence the shamanic death and rebirth….
The [near-death] reflex itself appears to be a paradoxical disconnection between the sympathetic and parasympathetic nervous systems, with vascular shunting away from the cortex with relative preservation of oxygenation to the brainstem and memory centers of the temporal lobes. This would account for the marked amount of catalepsy that occurs in the physical body while vivid imagery is simultaneously playing within the conscious mind….
There has now been enough significant research done in shamanic journeying and near-death experiences to realize that there needs to be an actual fear that one is losing one’s physical body and actually dying before the neardeath experience will manifest. This would seem appropriate as a protective mechanism to an animal in the jaws of a predator, who then reflexively collapses to avoid the pain of death. The feeling of “ecstatic rapture” that occurs is most likely mediated by certain chemoreceptors, such as beta-endorphins, as has been suggested by Candice Pert (Dossey 1989), and is identical to the “runner’s high” or any other physical stress that will produce a reflex endorphin surge in response to pain….
This state is also seen in lower animals and man as the “dive” reflex. In certain psychological experiments, laboratory animals have been placed into a pool of water that has no egress; after a period of frustrated swimming, the animal will dive to the bottom of the pool and die. On autopsy, there is no evidence of drowning but only that the heart stopped suddenly of an atrio-ventricular block. However, if the animal is rescued as the dive reflex is occurring and resuscitated, the animal can be put back into the pool and it will then swim for three to five times longer. This indicates that the animal has learned the concept of “hope” of rescue, and that there is “faith” in a higher power that it will not have to dive to the bottom and die.
This leads to the second aspect of the near-death experience that I feel is essential for the transformational aspect of the psyche: not only realizing that the physical body is dying but then consciously releasing the physical body from the personal will through the sudden acceptance of a Higher Authority. It is this subjugation of will that is the common feature of almost all persons who have had near-death experiences and have then had a transformation in their psyche in the way they live in the physical world….
This tends to follow the teachings of all the major religions of the world, all of which have stemmed from shamanic practices of stimulating neardeath experiences to make the shaman a “wounded healer” (Achterberg 1988). It is this “willingness” to guide the physical body through these experiences that allows the mystic to reach levels of understanding and compassion that could not otherwise be obtained….
The numerous techniques of achieving ecstasy that have developed over the past fifty millennia are distinctive, separate, and equally capable paths to that same, singular goal of an “asexual rebirth” into the same physical body found in the near-death experience (Eliade 1969; Eliade 1972; James 1982). This rebirth, in some cases, has been metaphorically referred to as “virginal,” as seen in the stories of the Jesus, Buddha, the Hindu’s Shiva, the Sumerian’s Mwuetsi, and the Egyptian’s Osiris, to name a few (Campbell 1949).
Amazing that ReVision would have published such a reductionistic piece, as it pretty much undercuts their whole spiritual worldview.
Biblio: Peters, Larry (1994), “The Internal Mystery Plays: the Role and Physiology of the Visual System in Contemplative Practices,” in ReVision, Volume 17, Issue 1, p. 3-11.