Consciousness is a spectrum. There are several states between a fully conscious state and a fully unconscious state. In medicine, the degree of loss of consciousness is measured by using Glasgow Coma Scale (GCS); a score between 3 and 15 is given to each person at any time, to show how conscious he or she is. Higher scores show more conscious states.
The opposite of consciousness is subconsciousness/unconscious mind. This means people do things that are instinctive and do not think about them like breathing and making one's heart beat.
It is not known what causes consciousness. So, it is difficult to know if another person or thing is indeed conscious. For example, if a robot seems to react to its environment, how does one know if it has consciousness (see artificial life)?
References[change | change source]
- Dorland, W.A. Newman. Dorland's Illustrated Medical Dictionary (29th edition ed.). WB Saunders. ISBN 0-8089-2186-X
- How Doctors Peer into the Minds of Vegetative Patients; Communicating with patients who appear to lack consciousness is becoming a reality May 2014 issue Scientific American