Hallucinations by Oliver Sacks

Source of book: Borrowed from the library

 

It is hard to believe that the last Oliver Sacks book I read was more than two years ago. In fact, it was the book I read on the last camping trip we did before the pandemic wreaked havoc on the world and shut a bunch of trips down that year. 

 

Previous books by Sacks: Island of the Colorblind, Musicophilia. As a practicing neurologist and teacher, Sacks had first-hand experience with a variety of fascinating neurological cases. In addition, he spent time researching, and eventually was flooded with letters from readers describing their experiences. This book, from 2012, is one of his later books, and sources the anecdotes from his practice, his readers, and from documented cases dating back hundreds of years. 

 The book covers a wide variety of hallucinatory events, divided into fifteen categories and thus chapters. To be clear, although there is some overlap, Sacks writes not about mental illness, but neurological phenomena - these are experiences that people know are hallucinations, or realize later were not real. People see, hear, sense, feel, smell, and so on things that do not exist, and that they are capable of understanding do not exist. 

 

I should disclose here as well that I myself have experienced several of his categories of hallucinations. Some are extremely common - delirium from fever (and while it is difficult to describe what I have experienced, I have always had them, and knew they were not “real” from a very young age. I also have occasionally had odd visions in the border between sleeping and awake. These too are very common. But perhaps the one most fascinating to me are the visual “auras” that precede migraines. I suffered from them in my teens (before I learned how they were connected to sugar late at night), and still get the auras from time to time, although they rarely lead to the headaches now that I know how to prevent them. 

 

As always, Sacks writes so descriptively about his topic, and also with compassion and a real knack for listening to his patients. No wonder he had a great reputation as a practitioner. 

 

There are so many fun facts and stories in the book, so the best I can do is find a few highlights. 

 

One of the questions that Sacks raises in the introduction turns out to be a theme in the book. While obviously hallucinations can give a lot of insight into the workings of the brain, what do they tell us about human culture? There seems to be a significant connection between common hallucinations and universal stories and themes in “art, folklore, and religion.” And, as he notes:

 

“Why has every culture known to us sought and found hallucinogenic drugs and used them, first and foremost, for sacramental purposes?” 

 

Sacks was not religious, but like William James (who he quotes extensively in the book - James documented a lot of neurological phenomena both in his epic work on psychology and his study of religious experience) - he is respectful of religious belief and experience. He just asks the obvious question as to how many “religious” experiences can be explained in terms of the way the brain works. He’s not trying to debunk religion, but rather examining the way that beliefs intersect strongly with actual physical experiences within our brains. 

 

The first chapter in the book is on Charles Bonnet Syndrome (CBS) - the phenomenon wherein people who lose eyesight often hallucinate where the gap has arisen. This idea forms the bedrock of the rest of the book. While not all hallucinations arise from deficits, they do occur in most people who lose a sense, even temporarily, and since Bonnet’s studies in this area were really the first truly scientific examination of hallucinatory experiences, the understanding that resulted led to increasing understanding of brain patterns in the centuries thereafter. 

 

From there on, the book moves to other sensory deficits, such as sound, and smell. Yes, smell. This chapter was interesting to me for a few reasons. First is that, unlike most people, I can imagine smells vividly and recall them to mind without difficulty. So I’m special, I guess? 

 

But smells, when hallucinated, are indeed very vivid (and often in a bad way), and like visual hallucinations, can sometimes be outside of reality and normal human experience. (The difference between, say, seeing little green men, and seeing something unknown to the universe.) In some cases, smells that are not “like” anything and which are not tied to memories can be hallucinated. Sacks points out that this is one way to know something is hallucinated.

 

New, unprecedented experiences can be a hallmark of hallucinations, for when the brain is released from the constraints of reality, it can generate any sound, image, or smell in its repertoire, sometimes in complex and “impossible” combinations. 

 

One of the disturbing things that Sacks discusses is how people have been afraid to talk about hallucinations for fear of being labeled “crazy” - and in some cases institutionalized. For years, “hearing voices” was misdiagnosed as schizophrenia and considered a severe mental disturbance, when in fact, it is often just a neurological event. Fortunately, this has changed for the better in recent decades. 

 

One of the great stories in the book is the one in which a group of researchers presented themselves to various institutions complaining of hearing voices, and were admitted as mentally ill. While there, they took notes - quite openly - the “writing behavior” was entered into the charts. The crazy thing is, while the staff seemed to be easily fooled by these pseudopatients, the real patients figured out easily that they were not crazy. 

 

Also interesting in this context is the fact that the belief that hearing voices was a sign of mental illness is fairly recent. Before the 17th Century, it was widely believed that hearing voices was normal - they were “ascribed to supernatural agencies: god or demons, angels or djinns.” 

 

I will note as well that I have heard voices myself, usually in either the state of fever or in that weird place when half asleep, although I think I have hallucinated someone calling my name on a few occasions. And, guess what? That is actually quite common. I haven’t ever had a true hallucinatory experience in the context of religion though, which has been, in a way, a reason that I have questioned so much about those who claim it is easy to “hear god’s voice.” This is not to say I have never experienced transcendence - but that usually is connected to music. 

 

One thing I had no idea about was the way that a certain treatment for Parkinsons - L-Dopa - tends to cause complex hallucinations. It isn’t universal, but it is common enough, and in some cases, it can be so distracting that treatment needs to be stopped. Unlike CBS, these can have whole narrative arcs, and involve a different area of the brain, leading researchers to believe that they might be an example of dreams invading waking consciousness. 

 

This book would not be complete without a chapter on altered states of consciousness. Sacks is open that he experimented with various mind-altering drugs in his youth, including LSD back when it was legal. I think that Sacks understands a central need of human psychology really well, so I have to quote his opening to the chapter. 

 

Humans share much with other animals - the basic needs of food and drink or sleep, for example - but there are additional mental and emotional needs and desires which are perhaps unique to us. To live on a day-to-day basis is insufficient for human beings; we need to transcend, transport, escape; we need meaning, understanding, and explanation; we need to see overall patterns in our lives. We need hope, the sense of a future. And we need freedom (or at least the illusion of freedom) to get beyond ourselves, whether with telescopes and microscopes and our ever-burgeoning technology or in states of mind which allow us to travel to other worlds, to transcend our immediate surroundings. We need detachment of this sort as much as we need engagement in our lives.  

We may search too, for a relaxing of inhibitions that makes it easier to bond with one another, or for transports that make our consciousness of time and mortality easier to bear. We seek a holiday from our inner and outer restrictions, a more intense sense of the here and now, the beauty and value of the world we live in. 

 

That’s just a wonderful way of writing about it too. I won’t quote further from this chapter, but I think that Sacks is one of the more thoughtful writers on these altered states of consciousness. My own drugs of choice are alcohol and caffeine in moderation (caffeine is very effective for me, which is why I can’t drink it after 3 PM, and as an introvert, a little social lubrication helps in various situations.) I have never experienced anything psychedelic, unless you count a high fever. Just not my thing. 

 

The chapter on migraine was excellent, and was followed by an equally excellent chapter on epilepsy. I don’t think I have ever disclosed this on my blog, but my mother is epileptic (thankfully, medication works for her.) I hadn’t realized before reading this book just how connected migraines and epileptic seizures are - and that probably my migraines are part of my genetic inheritance from my mother. (The others are my short stature and 45 years of good eyesight before age caught up with me.) Before she got the necessary treatment, I got to experience quite a few of those grand and petit mal seizures when I was young. It gave me the ability to understand what they look like, the auras that precede them, and how to keep a person fairly safe through the event. Somehow, I never drew the connection between the auras, though. 

 

My own aura is a very stereotypical visual disturbance in the right field of my vision. It is enough that it can make reading difficult or impossible with its yellow and black zigzags in the shape of a crescent moon. I find it interesting that Sacks (who got the auras but not the headaches like his mother) had the disturbance on the other side. 

 

This whole chapter was fascinating, with so many similarities yet differences from my own experience. I also thought that Sacks’ tie-in of Lewis Carroll was fun. Apparently, Carroll had migraines too, and some of the visual disturbances he experienced probably inspired passages in Alice in Wonderland. 

 

Sacks notes that, like migraines, epilepsy has been known from the dawn of human history. It is fairly common, and while it is culturally universal, the responses to it have varied widely. In some, obviously, epilepsy was viewed as “demon possession,” while in others, a sign of divine inspiration. Sadly, the response of fear, hostility, and discrimination has been the more common one. Modern medicine has removed some of the stigma, but there still is some, although not as much as for mental illness. One of Sacks’ goals with this book is to further remove stigma, and explain the way that our brains function, and what dysfunction looks like. 

 

The question of causes is interesting - and it is why I didn’t connect my migraines to my mom’s epilepsy. In general, epilepsy is caused by a brain lesion, either congenital or from an injury. (Another friend with epilepsy got his from surgery for an aneurysm.) In my mom’s case, she thought she got it from a head injury when she was very young. Which is entirely plausible. However, now I wonder if it might have had a genetic component which I inherited. 

 

One other thing that was unexpected and fascinating in this chapter was the life of Dostoyevsky. He too was epileptic, and there seems to have been a connection between his disease and significant personality changes as he aged. To some degree, this can be seen in his writing - from the realism of his early novels, to his more mystical and symbolic later works. But even more interesting to me is this:

 

It was this change, seemingly progressing even between Dostoevsky’s seizures (“interictally,” in neurological jargon), that especially fascinated the American neurologist Norman Geschwind, who wrote a number of papers on the subject in the 1970s and 1980s. He noted Dostoevsky’s increasingly obsessive preoccupation with morality and proper behavior, his growing tendency to “get embroiled in petty arguments,” his lack of humor, his relative indifference to sexuality, and, despite his high moral tone and seriousness, “a readiness to become angry on slight provocation.” Geschwind spoke of all this as an “interictal personality syndrome” (it is now called “Geschwind syndrome”). Patients with it often develop intense preoccupation with religion…

 

While trying to do an armchair diagnosis of what went wrong with my parents in my teen years is probably impossible, this passage really hit home. My mom attempted to go off her medication and find an “alternative medicine” solution to her illness, and, predictably, had a series of seizures, sometimes in public, that eventually led to her going back to what was working. But I feel like something changed in her over that period very much like what is described above. So, I wonder. Obviously, getting into Bill Gothard was a huge factor, and the general turn of white evangelicalism toward fundamentalism and authoritarianism, as was a certain incident involving race for my dad. So, it is clearly complicated. But, looking back, I really do feel like there was a personality change for my mom over that period, and so much of the religious obsession, the preoccupation with legalistic “morality,” and the totally stupid petty fights she picked with my wife for years, may have had a partly organic cause. Not that I can do anything about it, but I do wonder. 

 

The chapter on delirium was also fascinating. I was sick a lot as a kid, and I knew that during the height of the fever, I would have weird delirium and hallucinations - I hated it, but at least I was prepared and knew it would pass. Here is a description from a case study:

 

“What made them so strange is that they weren’t sensory hallucinations, but a hallucination of an abstract idea…a sudden dread of a very, very large and growing number (or a thing, but a thing I never really defined)...I remember pacing up and down the hallway…in a growing state of panic and horror at an exponentially increasing, impossible number…My fear was that this number was violating some very basic precept of the world…an assumption we hold that absolutely should not be violated.”

 

I knew immediately what this person was talking about. For my own delirium, it was a sensation combined with the numbers. At its core, it was a prickle, a pointiness, a rawness. As if a bed of nails or blunt spikes was flowing in a river - but solid, not entirely liquid. Maybe like lava. And it would start with narrow ribbons, so maybe four spikes across. And then grow, and it would be an overwhelming impossible number infinitely broad and lacerating. Over the course of the hallucination (which could last hours), it would break apart, split into streams, flow over everything, overwhelm me, and seemingly the world. Eventually, it would subside into smaller streams, and I would fade into sleep. But it was deeply unpleasant, far too “real” even though unconnected with anything earthly. I also remember that I kept my eyes closed during this, because if I opened them, nothing looked familiar in my room. It was all somehow monstrous beyond the border of my bed - and especially the heaving whatever it was that replaced the walls of the room. The few times I tried to get up, I was either paralyzed (see a later chapter in the book!) or I would pass out and wake up on the floor. So I learned to just ride it out, clinging to my blankets as the only thing that felt “real” during an episode. 

 

I don’t think I have ever really explained that before. I think I probably said something to my parents back in the day, but I was too young to really put it into words. Indeed, I think it took a few adult experiences to really understand what was happening. I can understand why my parents worried that maybe we had a demon in the house - it was kind of scary stuff for any parent, and my attempts at explaining sleep paralysis and the true “night-mare” involving something holding you down or sitting on your chest, given a particular belief system, could easily look like a supernatural and malevolent oppression. It was in my late teens and early twenties that I started trying to analyze my experiences from a changing paradigm. I hated the idea of demons lurking behind every door, and came to truly believe that there was nothing in particular about me that would be inviting that sort of thing. And a belief in a powerful and benevolent God seemed incompatible with continual harassment from the supernatural, honestly. But more than that, I knew that this was always associated with a physiological state - I was SICK. So it made more sense that it was something in my own body - my brain specifically - than something outside it. Oh, and those stupid viruses. (Related: thank science for flu shots - they have been a real life-changer.) 

 

Speaking of nightmares…

 

The term originally comes from the hallucination of an old woman who suffocated sleepers by sitting on their chests. I have experienced something like this. Fortunately, not having the superstition as to what it was, I never actually died from this. But people did, apparently. Frightened to death. But that is what the term is from - the woman of the night. 

 

Sacks points out that these superstitions have never gone away, of course. And that includes the hallucinations that contributed to the Salem Witch Trials. 

 

The conditions and pressures in Loudun or Salem hay have been extraordinary, though witch-hunting and forced confession have hardly vanished from the world; they have simply taken other forms. 

 

In our time, women are still targeted. But also LGBTQ people, who, by magic voodoo witchcraft somehow turn heterosexual kids gay… 

 

One final mention is the chapter on phantom limbs. I was fairly familiar with the idea, but there were some things I did not know. For example, some people who are born without limbs nevertheless have phantom limbs - including hands that they can move in their minds. Not all, though. The theory is that it depends on how the brain developed in the areas that contain self-conception. But this is why prosthetics work as well as they do for some people - they can literally map their self-consciousness of that limb onto the prosthetic, which greatly aids in learning to use it effectively. The brain is pretty dang amazing - and we really understand just a tiny fraction of how it works. 

 

Oliver Sacks is one of those authors that I recommend to anyone - including my kids - interested in neuroscience, particularly in its most human form. This book was delightful from beginning to end.