Experts say it could change the way consciousness disorders are classified and may be a practical method for discovering the needs of patients, even whether they still want to live.

Disorders of consciousness come in shades of gray, from severely impaired "vegetative states" to the perplexing "minimally conscious state" in which people slip into and out of awareness.

Early interactions set the child's beliefs about themselves as a social being and these encounters can create a self - consciousness that may lead to anxiety disorders and social phobia.