"I was to get a vivid idea what mental imagery could be like," the famed neurologist Oliver Sachs recalled, "when, during the 1960s, I had a period of experimenting with large doses of amphetamines. These can produce striking perceptual changes including dramatic enhancements of visual imagery and memory (as well as heightenings of the other senses, as I describe in 'The Dog Beneath the Skin,' a story in The Man Who Mistook His Wife for a Hat
). For a period of two weeks or so, I found that I could do the most accurate anatomical drawings. I had only to look at a picture or an anatomical specimen and its image would remain both vivid and stable, and I could easily hold it in my mind for hours. I could mentally project the image onto the paper before me -- it was as clear and distinct as if projected by a camera lucida -- and trace its outlines with a pencil. My drawings were not elegant, but they were, everyone agreed, very detailed and accurate, and could bear comparison with some of the drawings in our neuroanatomy textbook. This heightening of imagery attached to evervthing -- I had only to think of a face, a place, a picture, a paragraph in a book to see it vividly in my mind. But when the amphetamine-induced state faded, after a couple of weeks, I could no longer visualize, no longer project images, no longer draw -- nor have I been able to do so in the decades since."