Have you ever wondered what is happening in your central nervous system during meditation, especially during the 'high' states of mystical perception which are the fruit of meditation practice? If so, then you are not alone, because scientific researchers have been wondering too.
The mystical experience has been recorded in every religion, culture and age of mankind. There appear to be several common distinguishing features of mystical experience.
The mystical experience is classically reported to result from long practice of contemplation and meditation though it has also occurred spontaneously. It is reported to sometimes be induced through psychedelic drugs such as psilocybin, LSD etc. but this is distinct from the usual experience brought about by their ingestion. It has also been reported in extremely stressful situations such as prolonged sleep or food deprivation, severe anoxia (oxygen deficiency), hypoglycaemia (low blood sugar level leading to coma), severe fevers, intense prolonged pain, extreme sensory exhaustion, schizophrenic and psychotic reactions and various psycho-pathological conditions such as brain tumours.
It has been found that there are two opposing principles always at work in man's nervous system, excitatory (E) and inhibitory (I). Excitatory action is mediated via the sympathetic nervous system while inhibitory action or relaxation is mediated by the parasympathetic nervous system. In each internal organ system of the body, the level of nervous activity at any time is the balance between excitatory sympathetic action and inhibitory parasympathetic action. Similarly, in the brain the level of mental activity at measured by EEG is the resultant of opposing excitatory and inhibitory activity. In the musculo-skeletal system also the same principle is at work. The amount of contraction/excitement in the muscles of the body are measured by EMG again represents the balance between the two opposing forces.
The following table compares the two opposing actions in man's nervous system.
|E-excitatory action||I-inhibitory action (relaxation)|
|Cerebral cortex||Beta and Alpha waves (on EEG)||Slow aplpha waves|
|Theta waves (on EEG)|
|Awake - excited||Rhythmical wave ptterns|
|REM (dream) sleep||Awake → dozing, relaxed non-dreaming sleep|
|Peripheral autonomic nervous system||Sypathetic activation||Parasympathetic activation|
|↑ heart rate||↓ heart rate|
|↑ blood flow||↓ blood flow|
|↑ respiration||↓ respiration|
|↑ instestinal action and secretion||↓ instestinal action and secretion|
|↑ skin temperature||↓ skin temperature|
|↑ sweating||↓ sweating|
|Skeletal (voluntary)||↑ EMG activity in muscle contraction, tension||↓ EMG activity in muscle relaxation and lack of tension|
|(↑ increase)||(↓ decrease)|
The important principle here is that there is a reciprocal relationship existing between excitation (E) and relaxation (I) in the nervous system. This is because the activation of one force automatically suppresses the other. In other words, if there are x units J excitation then there will automatically be 1/x units of relaxation working in the other direction. The relationship between E and I is always B (excitation) x I (relaxation) = 1 within the normal dimensions of consciousness. If you do not understand this relationship between excitation and relaxation, then the principle can be understood through contemplation of the Chinese yin/yang symbol.
From the table you can see that in meditation we seek to move in the inhibitory direction creating overall relaxation in the central nervous system. The muscles are progressively relaxed, the autonomic functions such as respiration, digestion and so on are only minimally active and the EEG shows progressive decrease of excitation in the brain. In fact each of the stressful situations previously listed is known to push the overall E:I balance of the nervous system very far in one direction or the other. What scientists have suggested is that at the extremes where x becomes very large and 1/xis correspondingly very small there can occur an "unhinging" of the normal relationship between E and I. Then the relationship E x I = 1 breaks down and so too do the normal dimensions of consciousness. At this point there can occur a derailment in the train of consciousness and there is a new non-ordinary perception of reality corresponding to the dawning of mystical experience.*
When you sit for meditation, what you are doing is progressively swinging the nervous system in the inhibitory direction, producing increasing relaxation throughout the body and mind. In fact, what is normally termed meditation is more correctly termed dharana (concentration of the mind) and pratyahara (sense withdrawal). These practices are actually preparations for meditation. They prepare the nervous system and when relaxation reaches the crucial point, meditation results. There is some scientific evidence to suggest that at the extreme of relaxation, there is a sudden large rebound swing in the excitatory direction, followed by disruption of the E/I relationship throughout the nervous system. At such times dhyana (true meditation) is experienced.
This is not to say that daily meditation practice has no value. In fact, practices such as japa and antar mouna have been shown to relax the nervous system, perhaps more deeply than sleep states. These practices release the accumulated thoughts and feelings from the mind, freeing emotional energy which is bound up with the thoughts. Through daily practice there is a progressive relaxation and preparation of the nervous system for the experience of the mystic states of consciousness.
Recent evidence from Japan suggests that the practices of kundalini yoga such as bhastrika pranayama aim to bring about mystic awareness through first pushing the nervous system in the excitatory direction. This is the opposite approach, but will have exactly the same effect on the consciousness once the E/I balance is disrupted.
Yogis have long been aware of the opposing forces of excitation and relaxation in the central nervous system. The excitory nervous principle is known as pingala nadi or the sun nerve, corresponding to the right side of the body. The inhibitory principle is known as ida nadi or the moon nerve, corresponding to the left side of the body. In Chinese philosophy and acupuncture the excitatory expansive element is known as yang and the inhibitory contractive element is known as yin. Yin and yang never exist separately, but are the entwined universal principle.
Yogic physiology speaks of a third nadi, sushumna, which runs through the centre of the spinal column. The kundalini is said to rise up sushumna piercing chakra after chakra, bringing progressive enlightenment to the yogi. It culminates with the attainment of cosmic consciousness as the sahasrara chakra is pierced. The aim of meditation is to make the prana flow in the sushumna, This has been called the path to real knowledge and to success in meditative practice. The scientists speak of the 'unhinging' of, the normal excitatory/inhibitory balance of the nervous system producing mystical experiences. Yogis speak of the awakening of kundalini when the flow of prana is in sushumna rather than in ida and pingala. There is an exact parallel.
The rewards which come from meditation are very great. You can gain true knowledge of yourself and with it, liberation from limitations and sufferings. On the other hand you can go stark raving crazy and spend the rest of your days in a mental hospital. Unfortunately this has happened to some people who have taken to yogic practices without guidance or else have failed to obey the instructions of their teacher. Don't let this happen to you. If you wish to follow the path to real knowledge, you must have a guru who is completely familiar with this other dimension of consciousness. The teacher must know it inside out, he must have been there himself. Such a guru is called a satguru. Why settle for anything less? To set out on a long journey through dangerous mapped territory with anyone but an experienced guide would be very foolish.
After all, how safe would you feel if you knew your upcoming operation was in the hands of only a junior medical student?
Having been a medical student and having seen skilled surgeons in action, I know who I would ask for before signing the consent papers. On the spiritual path the situation is the same. Therefore, it is absolutely essential to find a true guru and ask him or her to guide you.