SummaryThe meaning of a disturbance of consciousness is completely different in an acute as opposed to a chronic stage. In the acute stage, the grade of arousal is the most essential component in order to assess the changes of the level of intracranial pressure in neurosurgical emergency room. A new coma scale called Emergency Coma Scale has been proposed, which represents a combination of the Glasgow Coma Scale and the Japan Coma Scale.In the chronic stage, however, contents of consciousness or mental function deserve phenomenological and holistic investigations, keeping the di¤erence between consciousness and mind in consideration, in order not only to treat and care for patients following cerebral injuries, stroke and mild cognitive impairment in aged people. We propose the di¤erence in conception between consciousness and mind; that is, consciousness consists of psycho-sensory a¤erent system, mind of psycho-motor e¤erent and a¤erent system, and memory and language as liaison o‰cers between them. This proposal would play a role to understand mental change in the natural aging processes, when memory and cognition are deteriorating gradually, but is still in evolution in the field of culture.