Hallucinations, neurological curiosities and a passion for understanding

Famed neurologist Oliver Sacks was nice enough to let the TEDBlog into his office for an interview before his talk went up today. He hosted us for over an hour, discussing his new book about vision and the mind and giving details on the visual hallucinations that he’s been experiencing since he lost vision in his right eye. Dr. Sacks proved as interesting as all rumors indicate, with an office full of his hobbies and interests — from his expanding geological collection to an antique crystal radio (made in 1915) and a Wimshurst machine, it was a little oasis for the curious mind.

You’re currently writing a new book on hallucinations …

Well, it’s not just hallucinations, but they’ll be about half the book. The current title is The Mind’s Eye and it’s about vision and visions and visual memory, as inspired in the first place by people coming to see me as patients or writing letters. I get something like 200 letters a day, of which I answer about 30. I can’t answer them all. But, I really feel very privileged because people write to me from all over and tell me interesting things that are going on with them. And, in a strange way, as a neurologist, I think I sometimes get my ideas in this way. You know, in health things are seamless. You would have no idea that color and motion and texture and depth are separately processed in the brain, because what we perceive, finally, is a whole visual world. But I often communicate with people who’ve lost just color perception or lost just stereo vision, which shows how things can go wrong. So yes, the hallucinations fascinate me, but mostly because they show how the brain works in everyday life.

But also, as a physician, I need to be in a position to reassure people with a particular sort of hallucination that they’re not going mad. They’re not losing their mind. And the word hallucination has bad vibes. It immediately suggests something ominous. It’s sort of a pity we don’t have another word. Although, curiously, I was just reading an 1824 book called The Philosophy of Apparitions and in those days “apparitions” was used, or “phantoms.” They’re both nice words. You talk about phantom limb, you don’t talk about a hallucinatory leg. Somehow, a phantom limb sounds better.