Review: Hallucinations, by Oliver Sacks

>>Published: November 2012

The perceptual transformations and hallucinations induced by mescaline, LSD, and other hallucinogens are predominantly, but not exclusively, visual. There may be enhancements or distortions or hallucinations of taste and smell, touch and hearing, or there may be fusions of the senses—a sort of temporary synesthesia—“the smell of a low B flat, the sound of green,” as Breslaw put it. Such coalescences or associations (and their presumed neural basis) are creations of the moment. In this way they are quite different from true synesthesia, a congenital (and often familial) condition where there are fixed sensory equivalences that last a lifetime. With hallucinogens, time may appear to be distended or compressed. One may cease to perceive motion as continuous and see instead a series of static “snapshots,” as with a film run too slowly. Such stroboscopic or cinematic vision is a not uncommon effect of mescaline. Sudden accelerations, slowings, or freezings of movement are also common with more elementary hallucinatory patterns.


Oliver Sacks, frequent NPR collaborator and author of such books as Migraine, Musicophilia, and Awakenings, returns with another bout of science-for-the-masses with his latest book, Hallucinations.

Hallucinations in and of themselves are not always easy to describe—or for that matter, simple to understand. There are an infinite number of ways hallucinations might present themselves to their unsuspecting hosts: as indefinable blotches of colour, or random sounds and voices without environmental sources, all the way to the more complex and sometimes worrisome examples of seeing and having conversations and interactions with people that don’t actually exist, to believing in entirely different realities from one’s own.

Equally numerous are the potential causes for hallucinations. Far from being a curse exclusive to the mad and the insane, hallucinations can be brought on by anything from a harsh migraine or sleeplessness, to sensory deprivation, drug use, Parkinson’s, and other illnesses—even a high fever can be enough to trigger hallucinations, given a person’s unique physiology and whether or not they are neurologically susceptible to such events.

Sacks’ Hallucinations is light on science and heavy on anecdotal evidence. He takes a combined academic and political approach to the material: first, breaking it down into the different potential causes and/or types of hallucinations; and second, by presenting individuals—friends, colleagues, and strangers and case studies met along the way, as if on a campaign trail—who are representative of these specific types of hallucinations. Hallucinations is, in essence, more of an anthology of experiences than it is a scientific exploration.

The book is highly approachable, and the first-hand accounts of many different sorts of hallucinatory events are often fascinating (and sometimes scary… the thought of waking up to the image of a child-sized spider on my chest and being unable to move would more than likely turn me into a lifelong insomniac). As a migraine sufferer who has also experienced music-based synesthesia for most of my life, I found myself understanding, to some degree, the confusion so many in the book confess to—of being “tricked” into believing the tangible existence of a hallucination, even for a moment, and the mix of disappointment and elation that can sometimes follow when reality slips back into place.

Most enlightening, however, were the details of Sacks’ years experimenting with hallucinogenic drugs and the very economical manner in which he details the effects. Though his experiments and brief bouts of addition didn’t seem to cause too many drastic repercussions on his own life, it makes for an interesting pairing with Marc Lewis’ Memoirs of an Addicted Brain, which was released earlier this year.

Hallucinations is a personal, yet surface-level exploration of a topic that demands far more in depth analysis than what is given in this book. As an entry point into the study of hallucinatory experiences and the causes and effects of them on the human body and mind, it opens a great many doors, but never steps all the way through to the other side. Sacks offers many different kernels of insight and explanation into some of our more misguided attempts to understand and accept hallucinations for what they are (and not always the harbingers of insanity we sometimes treat them as). However, given my curiosity for the topic at hand, I wish there had been a bit more science and a little less of a focus on personal anecdotes—no matter how interesting many of them happen to be. If for nothing else, Hallucinations has left me with a greater interest in the subject, one I hope to have the opportunity to explore further.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s