The physiological benefits of thoughtless awareness through Sahaja Yoga
At a physiological level, the state of thoughtless awareness has been shown to have numerous beneficial effects, especially on the parasympathetic and limbic systems. According to traditional yoga, there are seven energy centres in the body called Chakras, which correspond to the seven nerve plexuses: the pelvic autonomic plexus (Mooladhara Chakra), the aortic plexus (Swadhistana Chakra), the coeliac plexus (Nabhi Chakra), the cardiac plexus (Heart Chakra), the cervical plexus (Vishuddhi Chakra), and the optic chiasma (Agnya Chakra): (links to chakras.ppt?)The seventh energy centre is the limbic system of the brain, which consists of seven nerve nuclei which contains and integrates the control centers of the other six energy centers. (link to limbic.gif).

In the limbic system all of the six Chakras form this final integrative Chakra, the Sahasrara Chakra. Every Chakra thus has its corresponding alternative location at a particular location in the brain, which controls that particular energy center. Every one of these energy centers looks after the physical organs surrounding it, but is also responsible for the psychological processes which are connected to particular body organs. By using yoga mediation to energize this subtle system, which links both psychological and physiological properties, the body, brain and the mind become closely integrated.

This view of bi-directional interrelationships between body and mind is very different to the still prevalent Cartesian dualism of body and mind in our traditional western medicine, and can help to overcome conventional problems in defining the relationship between psychological and physiological processes. Physical damage to one of the Chakras in the body can have an effect on the controlling center of that Chakra in the brain (leading to concomitant psychological effects). These psychological problems can thereupon lead to psychosomatic disorders, which will manifest themselves in particular via those physical organs which are being controlled by the relevant regions of the brain.

Therefore, in yoga, body and mind are one, and are connected by this subtle energy system, which consists of many feedback loops between body energy centers and the energy centers of the brain. At the microscopic level, almost every receptor of every single cell in the body or the brain is folded in seven spanning loops (link to picture of seven spanning loops: Gilman, 1987, Dohlman, 1987, Fraser, 1991). This particular characteristic of all receptor types has again been postulated to be related to the seven energy centers in the body, reflecting mini-Chakras at the cell level (Mishra et al., 1989).

During a Sahaja Yoga meditation, a spiritual energy called the Kundalini, a coiled energy that resides at the base of the spine, raises through all the six centers of the body and enters the seventh center, the Sahasrara located within the limbic system. This energetic process of ascent activates and nourishes the parasympathetic nervous system, which in turn relaxes our bodily functions. It also gently nourishes the limbic system, the emotional and motivational center of the brain, which again relaxes the brain by reducing thinking functions. This parasympathetic-limbic activation is the underlying neurophysiological substrate of the enrichment of body and mind in Sahaja Yoga meditation.

Sahaja Yoga (SY) meditation thus claims to activate the parasympathetic-limbic pathway that relaxes body and mind (link to parasympathetic.ppt). According to this traditional yoga, the sympathetic nervous system is divided into a right-sided channel, which is predominantly coordinated by the left prefrontal part of the brain, and a left-sided sympathetic nervous system which is coordinated by the right hemispheric posterior parts of the brain (picture of Yin/Yang and brain). In our day to day lives we usually oscillate between these two 'functions of action' (activation of left prefrontal systems for action/thinking/future-planning/fight) and 'functions of inhibition' or retrieval (activating more posterior parts of the right hemisphere of the brain for inhibitory functions/memory/depression/flight).

This division of the sympathetic nervous system into 'fight and flight' mechanisms, with its different representation in the two sides of the cerebral hemispheres, is fundamentally in line with evidence from modern western neuroscience. In meditation, the parasympathetic nervous system is being activated, which, unlike the body-activating sympathetic nervous system, is responsible for bodily nourishment and recuperative functions, such as resting and restoration. The parasympathetic-limbic activation achieved through the meditation relaxes us by bringing us "into the center": the two opposing sympathetic functions are therefore synthesized into perfect balance and harmony with each other, giving us a more balanced personality.

Alterations in physiological parameters during Sahaja Yoga meditation
The relaxed state which one experiences subjectively in meditation is in fact accompanied by alterations in those physiological parameters which have traditionally been related to stress.
At the level of the physical body a series of physiological parameters have been shown to change after several weeks of SY meditation, supporting this postulated activation of the para-sympathetic nervous system.
1) Dilatation of pupils: The pupils of the eyes dilate, a sign of parasympathetic activation (Rai, 1993).
2) Decrease of pulse rate (Rai, 1993, Rai et al., 1988; link to Rai et al., 1998, 1997)
3) Decrease of the heart and respiratory rates (Rai, 1993, Rai et al., 1988, 1997)
4) Decrease in urinary homovanillic mandelic acid (Rai et al., 1988, 1997, Chugh et al., 1987, 1997)
5) Decrease of systolic blood pressure (Rai et al., 1998, Chugh, 1997)
6) Decrease in blood lactic acid (Rai et al., 1988, 1997, Chugh, 1997)
7) Increase in galvanic skin response (measure of decreasing sympathetic nervous activity) (Rai et al., 1991, 1988, 1997).
8) Decrease in the temperature in palm of hands and on top of the head, correlating with the experience of thoughtless awareness (Rai et al., 1991, 1988, 1993).
9) Increase in beta-endorphins: An interesting psychopharmacological study by Mishra et al. (1993; link to Mishra) from the McMaster's University in Canada, showed a 70% increase in plasma beta-endorphins in male subjects after SY meditation. The endogeneous opiates, b-endorphins, are known to have a role in body homeostasis. They strengthen the immune system, and are involved in the maintenance of a healthy psychological functioning. They can even combat cancer cells, which could explain so-called 'miraculous cures' in cancer patients after the practice of Yoga meditation.
All these measures indicate an increase in parasympathetic activation and a decrease in sympathetic dominance. Most of these parameters are typically elevated during stress, which is a manifestation of increased sympathetic activity.