Video from TED
Considering Human Consciousness: What Hallucination Reveals About our Minds - Oliver Sacks
"Neurologist and author Oliver Sacks brings our attention to Charles Bonnett syndrome -- when visually impaired people experience lucid hallucinations. He describes the experiences of his patients in heartwarming detail and walks us through the biology of this under-reported phenomenon.' from video introduction (September 2009)
Oliver Sacks, Exploring How Hallucinations Happen
This interview was originally broadcast on Nov. 6, 2012.
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.".. from the article: Oliver Sacks, Exploring How Hallucinations Happen