There are many forms of meditations. Most of the research has been done on Transcendental Meditation, popularly known as TM.

At the end of the day, whatever type of meditation is done, the end result is the same- the nervous system becomes calm and the muscular tension in the body is reduced. The focus of all forms of meditations is to bring the mind to a point when the senses are no longer intruding into the consciousness. In wakeful state, the nervous system is constantly stimulated. It experiences input from the senses, mainly the sights and the sounds in the environment. The senses of touch, smell and taste also have their input in stimulating the brain. The brain and the nervous system can get a rest from these stimuli if the person finds a quiet environment in which they can close eyes for a few minutes. But then something else starts to stimulate the nervous system from within.

When the person sits quietly, the thoughts and memories start to intrude in the mind. The more the person does not want the thoughts to come in, the more thoughts interfere, preventing the person to be stimulation free. In such a case the person starts fighting the thoughts. This never works successfully. One has to either ignore the thoughts or has to allow the thoughts to come in. These are techniques that are commonly taught in case someone has difficulties with meditation.

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