Oliver Sacks – author of "The Man Who Mistook His Wife For A Hat" and a neurologist who has himself experienced the phenomenon – studies hallucinations and how they can occur in seemingly healthy people. He also details what he and his patients have seen during their visions. Nelson says Sacks' strength is in making science relatable to the reader. "He's sort of the first in the breed of these science guys who can write in a lay manner," she says.
