Question: It is believed that human beings err because of the limitations in the nervous system that carry information from the external world to the brain for processing. How does yoga and meditation help in this?

The limitation of the human being is due to its unfixed mind. The yoga system identifies the root cause of this, and provides a complete solution based on its system of yama (rules) and niyama (regulations). There are eight steps of the ashtanga-yoga system which gradually bring one up to the point of perfection (samadhi). Before one begins the breathing exercises (pranayama), the sitting postures (asana) and the meditation, one must first purify his existence through various rules and regulations. This is explained in the Vedas as follows:

ahara-shudhau sattva shudhi sattva shuddhau dhruva-smritih
smriti-lambhe sarva granthinam vipramokshah

“By eating sanctified foods, one’s existence becomes purified. By the purification of one’s existence finer tissues in the memory become sanctified. When the finer tissues of remembrance become sanctified, all the knots within become untied.”

Thus the yoga system begins from the point of eating. We must regulate our selves starting with our food; and by this our existence becomes pure. As our existence is purified, the finer tissues in the memory develop. The knots in the nervous system become untied when the finer memory tissues are developed. Having come to this point one may actually begin yoga. Without coming to this stage of purification, any yoga endeavour is nothing more than gymnastics.

One who has developed this qualification to undertake yoga already has crossed the limitations you have mentioned.