Consciousness Redux: Measure More, Argue Less; February/March 2009; Scientific American Mind; by Christof Koch; 2 Page(s)

At the heart of science are judicious observations and measurements. This reality presupposes that something can be measured. But how can consciousness¿the notorious ineffable and ethereal stuff that can¿t even be rigorously defined¿ be measured? Recent progress makes me optimistic.

Consider a problem of great clinical, ethical and legal relevance, that of inferring the presence of consciousness in severely brain-damaged patients. Often the victims of traffic accidents, cardiac arrests or drug overdoses, such patients have periods when they are awake, and they may spontaneously open their eyes. On occasion, their head turns in response to a loud noise, or their eyes might briefly track an object, but never for long. They might grind their teeth, swallow or smile, but such activities occur sporadically, not on command. These fragmentary acts appear reflexlike, generated by an intact brain stem.