Hallucinations
By Oliver Sacks
(Knopf)

Enter a nondescript building in the West Village, ride an old elevator a couple flights up and suddenly you’re in a world of wonder long in the making.

You’ve entered the office of Dr. Oliver Sacks.

The well-worn lair of the world’s most literary neurologist bespeaks a restless spirit that all but says, “Yeah, I’ve been at this awhile.” A vintage, multicolor Chart of Electromagnetic Radiation dominates one wall; it looks like something you’d find in a gargantuan pack of chewing gum. On a table sits a pencil sharpener that looks more like a microscope. “It’s not even terribly functional,” he chuckles during a visit earlier this year. “It’s sort of a pencil sharpener cubed.”

At 79, Sacks’ eyesight is fading, as he chronicled in his 2010 book “The Mind’s Eye.” But his curiosity and empathy, immortalized in the 1990 Robert De Niro-Robin Williams movie “Awakenings,” remains unquenched. His new book, “Hallucinations” (Knopf), seeks to destigmatize the experiences of those who see what isn’t there. Much like his famous collection “The Man Who Mistook His Wife for a Hat,” “Hallucinations” mixes case studies of Sacks’ patients and acquaintances with scientific history and philosophy.

Then there’s the book’s big curveball. In the liveliest section, a mini-masterpiece of descriptive writing, Sacks dives into his own chemical experimentation.

It’s hard to sync the popular perception of the kindly graybeard doctor with a past of voracious drug consumption, but that’s what we get in the sixth chapter of “Hallucinations,” “Altered States.” Here we encounter young Dr. Sacks, doing his residency at UCLA, guided by medical interest and the ‘60s California zeitgeist. As he writes in the book, “I would never really know what hallucinogenic drugs were like unless I tried them.”

And try them he did. “My first pot experience was marked by a mix of the neurological and the divine,” he writes. Then he moved on to bigger game. A heaping dose of Artane, “a synthetic drug allied with belladonna,” led to a lengthy philosophical conversation with a spider. He snagged some morphine from his physician parents, injected, and watched the 15th-century armies of England and France do battle on the sleeve of his dressing gown.

There were less fanciful experiences as well: a severe case of post-sedative delirium tremens led to horrific visions on a city bus: “... All the passengers on the bus seemed to have smooth white heads like giant eggs, with huge glittering eyes like the faceted compound eyes on insects,” he writes.

Today Sacks looks back on his wilder days with mixed feelings.

“One has paranoid bad trips of all sorts, although mostly I found them enjoyable and sometimes instructive,” he says. “I don’t recommend them to anyone, but I don’t deny that I had them. Maybe I learned something, maybe I didn’t. Forty years later it took a little persuasion to get me talking about them.”

Sacks’ hands-on experiments are the most eye-catching parts of “Hallucinations.” The rest of the book offers up a variety of more sober hallucinatory experiences and conditions, from Charles Bonnet syndrome, which causes elaborate hallucinations among visually impaired or fully blind people, to migraine headaches, which Sacks has suffered throughout his life. Migraines are actually the subject of Sacks’ 1970 literary debut, “Migraine.”

“It’s something I’m still visited by fairly often,” he says. “Usually I only have visual hallucinations, patterns that can be very intricate and fascinating and rapidly changing. Sometimes I’ll have an olfactory one. Occasionally I’ll have a musical one.”

Musical hallucinations? You bet. Actually, these aren’t always for the ear only. Some Charles Bonnet patients, especially those with musical inclinations, hallucinate intricate patterns of musical notes, as if written on a white sheet of paper. A surgeon and amateur pianist with macular degeneration (in which the patient loses vision in the center of the visual field) recalls seeing a score made of “impossibly complex chords with six or more notes on a single stem, and horizontal rows of multiple flats and sharps.”

This is classic Sacks: collecting case histories of ordinary people living through extraordinary conditions, then turning them into lucid essays that require no expertise to comprehend.

“A detailed case history is a little like a nonfiction novel,” he says. “I regard many novels as, in effect, case histories. For me the idea of the individual who suffers from or is driven by some unusual circumstance is always at the center of my interests.

”I write for anyone who’s interested.“ (MCT)