The practice of coma arousal and brain stimulation in vegetative state or minimally conscious state is becoming the focus of heated debate. There is no definite theory on which patients may benefit, at what time in their recovery, or how the 'arousal' or 'stimulation' procedures should be applied. In this review, old and new therapeutic methods for recovery of vegetative state or minimally conscious state will discussed. And we consider some of the information processing mechanisms that are important mediators of arousal and awareness in current practices.