By Renée Grinnell

Markedly decreased alertness, to the point that the sufferer is nearly unresponsive; only basic stimuli can provoke a reaction.

Example: A man lies in a hospital bed and ignores you, even when you call his name. Painful stimuli make him groan and withdraw briefly.

    Last reviewed: By John M. Grohol, Psy.D. on 3 Nov 2008