With his special mix of patient case studies, historical accounts, reader correspondence and personal experience, Oliver Sacks has again found a way to unlock one of the mysteries of our brains. Hallucinations, his 10th book, explores the ways in which our minds play tricks on us, and he explores how those tricks, many of them now understood thanks to brain imaging technology, may have inspired art, folklore and religious beliefs throughout the ages.
Hallucinations caused by injury, illness, drugs — and sometimes even the lack of them — can bend and distort our perception of the real and the unreal. Sacks examines several types of hallucinations in a style he has perfected. He takes the whole concept a fascinating step further by looking at how hallucinations have become a part of our culture, even down to the word “nightmare.” Now used for any bad dream, it used to imply a specific type of hallucination. “The ‘mare’ in ‘nightmare’ originally referred to a demonic woman who suffocated sleepers by lying on their chests,” he explains. That feeling of paralysis and sometimes breathlessness is common across cultures.
Sacks notes that the term “hallucinations” was first used in the early 16th century, before everyone pretty much agreed that visions and voices of people who weren’t there represented either the divine or a dark underworld. They were called apparitions: ghosts, spirits, the voices of the deities or the devil. “Did Lilliputian hallucinations (which are not uncommon) give rise to the elves, imps, leprechauns, and fairies in our folklore? Do the terrifying hallucinations of the night-mare, being ridden and suffocated by a malign presence, play a part in generating our concepts of demons and witches or malignant aliens? Do ‘ecstatic’ seizures, such as Dostoevsky had, play a part in generating our sense of the divine?” Sacks wonders.
Sacks’ descriptions of the types of hallucinations people experience is fascinating and often funny. Not all hallucinations are frightening or inspiring. He describes one of the patients he treated at the hospital he wrote about in Awakenings who really enjoyed her nightly hallucinations. Gertie C. had entertained an amorous, hallucinated friend and told Sacks, “You surely wouldn’t forbid a friendly hallucination to a frustrated old lady like me!” He did not, and she learned to keep her imaginary visitor waiting until 8 p.m. If any real visitors stayed too late, she shooed them away, saying she was expecting company.
Sacks looks at epilepsy, migraines, narcolepsy and blindness. For the 10 percent of the population that suffers from migraines, his explanation of the auras they sometimes cause is fascinating. Some people see patterns or zigzags. Others find they have blind spots or see inanimate objects moving. Some people actually feel that they are larger or smaller than they are.
After describing this variety of experience, Sacks makes it relevant to the 90 percent of people who don’t have migraines: We learn that Lewis Carroll had migraines. Did they inspire Alice’s “strange alterations in size and shape” in Alice in Wonderland? Hard to know, but hard to discount.
Sacks also describes the hallucinations caused by drugs and alcohol, noting that many cultures have used hallucinogenic drugs as part of religious sacraments. And, like he does in many of his other books, Sacks includes his own experiences, this time from the 1960s, when he regularly used amphetamines, LSD, morning glory seeds and marijuana.
“My first pot experience was marked by a mix of the neurological and the divine,” he writes, adding that he saw his own hand grow into the hand of God.
Hallucinations are often perplexing mysteries for the people who have them. They can feel like symptoms of insanity, proof of an instable and unreliable mind, even when they’re not threatening. But Sacks notes that the mind’s ability to conjure images, sounds and sensations that are not there has a variety of causes and an even more fascinating array of consequences.
“Hallucinations, beyond any other waking experience, can excite, bewilder, terrify, or inspire, leading to the folklore and the myths . . . . which perhaps no individual and no culture can wholly dispense with,” he writes.
Susannah Nesmith is a writer in Miami.