Is it possible to communicate with an unconcious person using a computer?
By analysing the relative degrees of activity in parts of the brain, we can identify multiple gross states. We cannot yet use computers to read a person’s thoughts, but we can tell the difference between a person thinking of playing sport and a person thinking of their last holiday, because different areas of the brain are involved. Devices often used for this include electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). EEGs detect electrical activity, fMRI detects blood flow. Until the technology is sufficiently refined, you would have to rely on a simple yes/no code, something like, “think of moving your left hand for yes, and your right hand for no”. Note that an unconscious person is not responsive to this kind of communication in any way, since an unconscious mind is not open to communication by any method. The person would have to be simply paralysed or suffering from locked-in syndrome for this to be a feasable way of communicating.
