In order to gain a fuller understanding of the processes involved in pranayama generally, let us examine the processes which occur in nadi shodhana pranayama. In nadi shodhana there is a continual build up of ionic concentrations around ida and pingala nadis gradually reaching a higher level in the second, third, fourth and consecutive rounds. In normal breathing, however, there is no such build up.
This ionic build up around the nadis has several implications for the yoga practitioner. The first is that the amount of pranic energy in the body is greatly increased in its potentialities. This helps to maintain a high level of mental alertness and physical harmony. The practitioner is rendered virtually immune from most diseases, and certainly from those which have their origin in the mind (approx. 90%). The mental functions are all brought to a peak due to the interrelation of body-prana-mind.
The second implication is that there is a limit to which this energy build up can take place, and this limit is dependent on the practitioner as well as the environment. To elaborate further, as the concentrations rise progressively, they approach what we shall term a 'boundary condition'. This is the limiting degree of concentration (otherwise they would go on increasing forever and we might all become supermen). In most individuals this boundary condition is quite low, but with practice of yogic techniques, it is pushed up further and further, ultimately approaching a very high level. It is theorised that when the limiting boundary is eventually broken through, the yogi enters into the state of samadhi, nirvana or ultimate bliss, and the body consciousness is lost along with the experience of subject and object as duality. The level at which the boundary conditions occur is a reliable measure of the ability of the individual to meditate or concentrate. There are also other uses of determining the boundary level which are mostly concerned with yogic therapy.
The boundary condition appears when the concentrations of ions around ida and pingala reach a limit and must again decrease. This limiting or boundary condition forms a peak and the following points are to be noted about it. When the ionic changes in ida and pingala are equalised and homogenised i.e. when both have reached the boundary condition, the sushumna nadi acts as a dielectric, and at this point a discharge occurs across sushumna nadi which has the following effects:
Therefore, the energy or prana in both ida and pingala is also at a peak level, meaning that all the mental functions are at their maximum potential energy. Thus it can be seen how important it is to be able to remain in this condition and why it is said that for meditation, the sushumna nadi should be active or operative.
What happens after some time, if we do not try to maintain this state, is that there is an alteration of the predominance in the flow of the nostrils. This is the case in normal breathing. After the boundary condition is reached, the ionic concentration rapidly decreases, resulting in one of the nostrils predominating.
In nadi shodhana pranayama, a method to increase the time for which sushumna is active, the following occurs:
In fact we can say that the 'real' experience of nadi shodhana pranayama begins only after one has equalised the concentrations in ida and pingala, and maintained that condition for an extended period of time. What happens then resembles a 'chain reaction' of nuclear fission. It may be represented like this:
|Simple nadi shodhana||->||Equalised ionic charges||->||Boundary reached
|Further nadi shodhana in this condition||->||Second boundary reached||->||Further nadi shodhana at second boundary|
|Third boundary reached||->||Further nadi shodhana at third||->||Meditation commences at forth or fifth boundary|
Now, assuming that the above mentioned hypotheses are correct, we are in a position to redefine the higher stages of sense withdrawal and meditation in terms of ionic charge conditions. Thus we can say that: The ionoplasmic/mental energy required for meditation is only available when a certain level of concentration, harmonisation and direction is given to the three fields around the sushumna and the body/ mind complex.
Concentration of the ionic fields is accomplished by: asanas, pranayama, concentration, and meditation, practiced in a correct environment. It has been shown that at high altitudes (1,000 to 5,000 feet above sea level) it is much easier to absorb ions from the atmosphere than it is at sea level. Clean fresh air is also important for the satisfactory absorption of ions, since it has the correct ratio of negative to positive ions (1.2 to 1.00), whereas city air is often heavily polluted and has an excess of positive ions or a deficiency in both positive and negative ions.
Harmonisation is accomplished by the regular practice of symmetrical pranayamas, i.e. where equal stimulus is given to the right and left nostrils. Nadi shodhana up to advanced stages is recommended as well as bhastrika and ujjayi. For advanced practitioners of nadi shodhana and concentration techniques, We recommend that kriya yoga be practiced.
Correct direction is given to the ionic flow by keeping the body steady and avoiding stray electric fields and large metallic objects. These tend to influence the direction, due to a magnetic like attraction.
There are three types of composite fields operating in the body, and they are here specified in detail: Field A - ionic and pranic elements. Field B - magnetic and electromagnetic elements. Field C - mental and psychic elements. The main points concerning these fields are that:
It must be emphasised here that, at most, this is only a partial and somewhat inadequate account of higher psychic and spiritual phenomena which take place in the mind of the yoga practitioner or meditator. It is not meant to be the 'ultimate' scientific answer as to why spiritual experiences occur. There are many other factors involved which are not and cannot be subject to scientific investigation or analysis, such as the disciple's faith in his guru or the bestowing of spiritual power by touch of the guru to disciple. These and other such things were and will be in an entirely separate and inviolable category.