The so-called "near death experience" is described by many survivors as a sensation of floating with visions of bright lights and a tunnel. Some call it a preview of the afterlife. Now there's evidence that it may be a kind of last picture show staged by the brain demonstrating that it's still alive. When the heart stops, the brain displays a surge of activity with features associated with consciousness and visual activation. That's according to recent experiments with anesthetized rats. Jimo Borjigin, Associate Professor of Physiology and Neurology at the University of Michigan, conducted the research.