In Oliver Sacks‘ book The Mind’s Eye, the neurologist included an interesting footnote in a chapter about losing vision in one eye because of cancer that said: “In the ’60s, during a period of experimenting with large doses of amphetamines, I experienced a different sort of vivid mental imagery.”
He expands on this footnote in his book, Hallucinations, where he writes about various types of hallucinations — visions triggered by grief, brain injury, migraines, medications and neurological disorders.
One chapter of the book — that’s out in paperback July 2 — deals with altered states and Sacks’ personal experimentation with hallucinogenic and mind-altering drugs in the ’60s. He says the first time he tried marijuana, it induced fascinating perceptual distortion. He was looking at his hand, and it appeared to be retreating from him, yet getting larger and larger.
“I was fascinated that one could have such perceptual changes, and also that they went with a certain feeling of significance, an almost numinous feeling. I’m strongly atheist by disposition, but nonetheless when this happened, I couldn’t help thinking, ‘That must be what the hand of God is like.’ ”
Sacks tells Fresh Air‘s Terry Gross that he has always been fascinated with hallucinations — from reading about Pip’s hallucination of Miss Havisham in Charles Dickens’ Great Expectations to witnessing hallucinations of every sort as a medical student and doctor. He had a personal interest in the phenomenon, he explains, because his brother was a schizophrenic — and “would talk with his hallucinations.”
Sacks has also had his share of non-induced hallucinations. One day while mountain climbing, he experienced an auditory hallucination after an injury that tore most of his thigh muscle and dislocated his knee. His first impulse was to go to sleep — but then he heard a voice that he didn’t recognize yet trusted.
” ‘No, that would be death,’ ” he recalls it saying. ” ‘Go on. You’ve got to keep going. Find a pace you can keep up and keep it up.’ And this was a very clear, commanding voice. It was a life voice, and it was not to be disobeyed.”
Neurologically, Sacks speculates that this type of auditory hallucination is something that announces itself in extremity, and is “the ultimate safeguard, some power or propensity which has been built into the structure of the mind, the emotions,” and is not heard by most people in their lives.
Sacks notes that the medicalization of hallucinations really only occurred in the 19th century — and that subsequent to that, there was much more anxiety, secrecy and shame about hallucinations.
“I think hallucinations need to be discussed,” he says. “There are all sorts of hallucinations, and then many sorts which are OK, like the ones I think which most of us have in bed at night before we fall asleep, when we can see all sorts of patterns or faces and scenes.”
With the ability to visualize the brain through cutting-edge medical technologies, Sacks believes, the scientist’s sense of the brain’s complexity has been increased; it’s now possible to see exactly what’s going on in the brain while people are hallucinating.