Consciousness Lost and Found

The phenomenon of "consciousness" is intrinsically related to one's awareness of one's self, of time, and of the physical world. But what if something should happen to impair one's awareness? What do we make of "consciousness" in those people who have suffered brain damage, such as amnesia? This is the intriguing question explored by Lawrence Weiskrantz, a distinguished neuropsychologist who has worked with such patients over 30 years. Contrary to the perception that many have about brain-damaged patients, it has been discovered that many of these individuals retain intact capacities of which they are unaware, in what is known as `covert' processing. A blind patient, then, may actually be able to "see," without having knowledge of such success, while an amnesiac patient can be shown to learn and retain information that he or she does not realize is memory--nor can be made to realize. In fact, in every major class of defect in which patients lose cognitive ability--from perception, to meaning, to memory, to language--examples of preserved capacities can be found of which the patient is unaware. Weiskrantz starts with his research into this phenomenon, known to neuropsychologists but unfamiliar to many layreaders, and uses it as a springboard toward a philosophical argument which, combined with the latest brain imaging studies, points the way to specific brain structures which may be involved in conscious awareness. Weiskrantz takes his argument further, too, asking whether animals who share much the same brain anatomy as humans share awareness--and how that impacts our assumptions about evolution as well as our moral and ethical decision making. Written in an engaging and accessible style, Consciousness Lost and Found provides a unique perspective on one of the most challenging issues in science today.