Absolutely the brain is much aware of the condition of the hair and as well as hair cut or hair uncut. Even it has the sensible of being known that it is being cut up to its tip. This explains about the sure sign of life. The hair has some specific criteria’s towards ageing in their specifications like greying and as well as in the hair thickness growth. The condition of any person related to the health and other factors are all reflected in the hairs like shining and pigmentation etc. the lacking of sensation in hairs are nothing but no indication of dead or aging and even the brain does not shows such sensations. There is also some other criteria’s in which the animals also do not possess a nervous system at all.  Whatsoever a blow to any part of the human body also produces no response to this ageing response. So we cannot call these particular animals dead and also most of the plants which do not show any sensations like this either and we cannot call this as dead. The part of hair that we call it as dead without any sensation but cannot be considered that they are not functioning.