ABSTRACT
No alien space visitor could fail to observe that vertebrates, including humans, engage in purposeful motion for only two-thirds of the earthly day. In the remaining third, we hibernate. When consciousness returns in the morning, a massive change in eleetrical activity takes place all over the cortex, as the fast, small and irregular waves of waking electroencephalograph (EEG) replace the large, slow, regular hills and valleys of deep sleep. Accompanying this faster electrical activity, we humans report a rich and varied array of conscious experiences: colours and sounds, feelings and smells, images and dreams, the rich pageant of everyday reality. Because these reports of conscious experiences, purposeful action and electrical activity covary so perfectly, we routinely infer that they reflect a single underlying reality. And it is this underlying reality-consciousness-which is of central importance in human life.
