Hallucinations From the best-selling author of Musicophilia and The Man Who Mistook His Wife for a Hat, a provocative investigation into hallucinations-auditory, visual, tactile, olfactory-their many guises, their physiological sources, and their personal and cultural resonances. Hallucinations, for most people, imply madness. But there are many different types of non-psychotic hallucination caused by various illnesses or injuries, by intoxication-even, for many people, by falling sleep. From the elementary geometrical shapes that we see when we rub our eyes to the complex swirls and blind spots and zigzags of a visual migraine, hallucination takes many forms. At a higher ...