The practice of coma arousal and sensory stimulation is becoming the focus of heated debate. There is no theory on which patients may benefit, at what time in their recovery, or how the 'arousal' or 'stimulation' procedures should be applied. This paper considers some of the information processing mechanisms that are important mediators of arousal and awareness, pointing to some of the weaknesses in current practices and suggesting alternative approaches. Recommendations for a conceptual model of sensory stimulation are given that might provide a more scientific perspective to those who use such methods.