On August 30th, the world lost neurologist, Oliver Sacks, one of the human brain’s most beloved advocates. With decades of clinical experience behind him, Sacks wrote extensively, bringing his knowledge of the murky intricacies of the mind into the layperson’s living room. In his clinical practice and his writings, Sacks handled subjects that were often deemed frightening or alien, or even criminal or crazy, analyzing them with a compassion and a clarity that made the puzzles of the brain more accessible for everyone.
“Hallucinations,” one of his twelve books, delves into one of the most misunderstood and alarming mysteries of the human mind. Sacks draws from his many case studies on the subject of hallucinations, all of which are unique in their symptoms and presentations. He pulls the notion of hallucinations out of the shadows and the mental wards, and portrays them as the very natural expressions of the brain that they are.
Dreams, he says, are a type of hallucination, but they are not a part of the realm of the book’s scope, which still manages to cover plenty of fascinating variations of the phenomenon, which Sacks defines as, “percepts arising in the absence of any external reality.” He includes in his analysis the context of hallucinations as they have been chronicled throughout history, and how they have influenced the human story, seeping into art, literature, myths, and religion. In some places in the world, hallucinations are seen as a spiritual blessing, but not so in many western cultures, where there is a presumption that the delusional experience signals a weakness or a mental defect.
Once Sacks establishes the big picture, and the cultural framework of hallucinations, he narrows his focus and lays out, example by example, the many intriguing ways in which hallucinations seem to interact with the sensory parts of the brain. For example, hallucinations are a common occurrence for people who have lost their vision. These types of hallucinations are very complex, blasting the notion that the mind is a blank canvas upon which the senses paint their pictures and memories. The complexities of sight remain within the brain even after sight is lost.
Sacks points out that the brain seems to compensate when a prolonged stretch of sensory deprivation occurs, which may be one reason many elderly, bedridden individuals see hallucinations. Many visions are pleasant and benign, even exceedingly colorful and detailed. Unlike with dreams, people who experience hallucinations are never involved in whatever is taking place; there is no narrative and no participation; instead the hallucinations play out in a rather cinematic fashion.
Even though the nature of a hallucination means that it is removed from the actual physical realm of a person, the experience can be exceedingly distressing and scary, since the impression of reality is significant and most often unwanted. Sacks does point out that with drugs people can enter a hallucinatory state very willingly and with intent.
It is within this framework that the book is really compelling, as Sacks gets personal and shares his own experimentation—and eventual struggle—with hallucinatory drugs when he was a young graduate student. He is quick to point out that the deliberate use of certain drugs has been a component of many religious rituals and traditions throughout history, arguing that the reasons can range from the individual seeking a clarity of perception, to pleasure-seeking only.
Since Sacks is able to share the details of drug-induced hallucinations from his own personal experiences instead of merely from third person anecdotes, the details are more elaborate and fleshed out, making for fascinating reading. In fact, it is a bit surprising to discover that Sacks lived to a ripe old age, given the extents to which he pushed the hallucinatory envelope. Very little was off-limits and he undertook his experiments in a lackadaisical fashion, without supervision, more in line with a junkie than a neuroscientist-in-training. Cannabis, LSD, morning glory seeds, morphine, and a synthetic form of belladonna, among others, all contributed to his collection of hallucinatory adventures.
In addition to sharing his own closet’s skeletons, he reveals many renowned individuals who also hallucinated, though not all because of drug use. Lewis Carrol, Joan of Arc, Dostoevsky, and Edgar Allan Poe were all sufferers of some sort of hallucinations. Migraines, epilepsy, and narcolepsy, among other ailments, can induce them, for example.
Sacks weaves in their stories as he flits from one variation of a delusion to the next—hearing voices, phantom limbs, and bereavement hallucinations all find a place in his very readable, but thorough analysis. In “Hallucinations,” he manages to write with a magical clarity, while demystifying the intangible, reminding the reader that there is still much mystery to the human condition.