Hallucinations

by Oliver Sacks

Many people with narcolepsy have auditory or tactile hallucinations along with visual ones, as well as complex bodily feelings. Christina K. is prone to sleep paralysis, and often her hallucinations go with this, as in the following episode:

  I had just lain down in bed, and after a few rounds of changing positions I ended up face down. Almost immediately I felt my body go more and more numb. I tried to “pull” myself out of it, but I was already too deep into the paralysis. Then it was almost as if someone sat down on my back, pressing me deeper into the mattress … the weight on my back got heavier and heavier, and I was still not able to move. [Then] the thing on my back got off and laid down next to me.… I could feel it lying beside me, breathing. I got so scared and thought that this couldn’t be anything other than real … because I had been awake all along. It felt like an eternity before I managed to turn my head towards it. Then I laid eyes on an abnormally tall man in a black suit. He was greenishly pale, sick-looking, with a shock-ridden look in the eyes. I tried to scream, but was unable to move my lips or make any sounds at all. He kept staring at me with his eyes almost popping out when all of a sudden he started shouting out random numbers, like FIVE-ELEVEN-EIGHT-ONE-THREE-TWO-FOUR-ONE-NINE-TWENTY, then laughed hysterically.… I started feeling able to move again, and as I came back to a normal state the image of the man became more and more blurry until he was gone and I was able to get up.

  Another correspondent, J.D., also described the hallucinations associated with sleep paralysis, including the feeling of pressure on her chest:

  Sometimes I would see things like huge centipedes or caterpillars crawling all over my ceiling. Once I thought my cat was on the shelf in my room. She seemed to be rolling around and turning into a rat. The worst was when I would hallucinate that a spider was on my chest. I couldn’t move. I would try to scream. I am TERRIFIED of spiders.

  On one occasion, she had a hallucination resembling an out-of-body experience:

  I hallucinated that my body floated up to the ceiling towards the end of my bed, and then all of a sudden my body quickly dropped through the floor to the first level of the house and then dropped through that floor and into the basement. I could see everything in each room. The floors did not seem to break when I went through them. I just passed through them.

  There was little physiological understanding of sleeping, dreaming, or sleep disorders until 1953, when Eugene Aserinsky and Nathaniel Kleitman at the University of Chicago discovered REM sleep—a distinctive stage of sleep with characteristic rapid eye movements, as well as characteristic EEG changes. They also found that if their subjects were woken during REM sleep, they would always report that they had been dreaming. It seemed, then, that dreaming was correlated with REM sleep.3 In REM sleep the body is paralyzed, except for shallow breathing and eye movements. Most people enter the REM stage ninety minutes or so after falling asleep, but people with narcolepsy (or those with sleep deprivation) may fall into REM at the very onset of sleep, plunging suddenly into dreaming and sleep paralysis; they may also wake at the “wrong” time, so that the dreamlike visions and the loss of muscle control characteristic of REM sleep persist into the waking state. Even though the person is wide awake, he may be assaulted by dream- or nightmare-like hallucinations, made even more terrifying by an inability to move or speak.

  But one does not have to have narcolepsy to experience sleep paralysis with hallucinations—indeed, J. A. Cheyne and his colleagues at the University of Waterloo have shown that somewhere between a third and half of the general population has had at least occasional episodes of this, and even a single episode may be unforgettable.

  Cheyne et al. explored and categorized a huge range of sleep-paralysis-related phenomena, based on reports from three hundred student subjects as well as a large and varied population who responded to an internet questionnaire. They concluded that isolated sleep paralysis (that is, sleep paralysis without narcolepsy), being relatively common, “constitutes a unique natural laboratory for the study of hallucinoid experiences” but stressed that such hallucinations cannot be compared to ordinary hypnagogic or hypnopompic experiences. The hallucinations accompanying isolated sleep paralysis, they wrote, are “substantially more vivid, elaborate, multimodal and terrifying,” and therefore more likely to have a radical impact on anyone who experiences them. These hallucinations may be visceral, auditory, or tactile as well as visual and are accompanied by a feeling of suffocation or pressure on the chest, the sense of a malignant presence, and an overall sense of absolute helplessness and abject terror. These, of course, are the cardinal qualities of the nightmare, in its original sense.

  The “mare” in “nightmare” originally referred to a demonic woman who suffocated sleepers by lying on their chests (she was called “Old Hag” in Newfoundland). Ernest Jones, in his monograph On the Nightmare, emphasized that nightmares were radically different from ordinary dreams in their invariable sense of a fearful presence (sometimes astride the chest), difficulty breathing, and the realization that one is totally paralyzed. The term “nightmare” is often used now to describe any bad dream or anxiety dream, but the real night-mare has dread of a wholly different order; Cheyne speaks of “the ominous numinous” here. He suggests that the term for the night-mare proper be spelled with a hyphen, and this convention has been adopted by other workers in the field.

  Shelley Adler, in her book Sleep Paralysis: Night-mares, Nocebos, and the Mind-Body Connection, also brings out the extreme nature of the sense of terror and doom that makes the experience of sleep paralysis unlike any other. She emphasizes that night-mares, unlike dreams, occur when one is awake—but awake in a partial or dissociated way; in this sense, the term “sleep” paralysis is misleading. The terror of this state is heightened by the shallow breathing of REM sleep and a rapid or irregular heartbeat, which can go with extreme excitement. Such overpowering fear and its physiological accompaniments can even be fatal, especially if there is a cultural tradition that associates sleep paralysis with death. Adler studied a group of Hmong refugees from Laos who had immigrated to central California in the late 1970s and were not always able to perform their traditional religious rites during the upheaval of genocide and relocation. In Hmong culture, there is a strong belief that night-mares can be fatal; this evil expectation, or nocebo, apparently contributed to the sudden unexplained nocturnal deaths of almost two hundred Hmong immigrants (mostly young and in good health) in the late 1970s and early 1980s. Once they were more assimilated and the old beliefs lost their power, the sudden deaths stopped.

  The folklore of every culture includes supernatural figures like the incubus and succubus, which assault the sleeper sexually, or the Old Hag, which paralyzes its victims and sucks their breath away. Such images seem to be universal—indeed, there is a remarkable similarity of such figures in widely disparate cultures, although there are local variations of every sort. Hallucinatory experiences, whatever their cause, generate a world of imaginary beings and abodes—heaven, hell, fairyland. Such myths and beliefs are designed to clarify and reassure and, at the same time, to frighten and warn. We make narratives for a nocturnal experience which is common, real, and physiologically based.

  When traditional figures—devils, witches, or hags—are no longer believed in, new ones—aliens, visitations from “a previous life”—take their place. Hallucinations, beyond any other waking experience, can excite, bewilder, terrify, or inspire, leading to the folklore and the myths (sublime, horrible, creative, and playful) which perhaps no individual and no culture can wholly dispense with.

  1. Bill Hayes, in his book Sleep Demons, cites an even earlier reference to irresistible, overwhelming sleepiness and probable cataplexy—“It falls upon them in the midst of mirth”—from a little-known 1834 book, The Philosophy of Sleep, by the Scottish physician Robert Macnish.

  2. A key figure in the narcolepsy world is Michael Thorpy, a physician whose many books on narcolepsy and other sleep disorders have grown out of a lifetime of experience directing a slee
p disorders clinic at Montefiore Medical Center in the Bronx.

  3. This simple equation had to be modified later, when it was found that dreams—albeit of a somewhat different kind—could also occur in non-REM sleep.

  13

  The Haunted Mind

  In Charles Bonnet syndrome, sensory deprivation, parkinsonism, migraine, epilepsy, drug intoxication, and hypnagogia, there seems to be a mechanism in the brain that generates or facilitates hallucination—a primary physiological mechanism, related to local irritation, “release,” neurotransmitter disturbance, or whatever—with little reference to the individual’s life circumstances, character, emotions, beliefs, or state of mind. While people with such hallucinations may (or may not) enjoy them as a sensory experience, they almost uniformly emphasize their meaninglessness, their irrelevance to events and issues of their lives.

  It is quite otherwise with the hallucinations we must now consider, which are, essentially, compulsive returns to a past experience. But here, unlike the sometimes moving but essentially trivial flashbacks of temporal lobe seizures, it is the significant past—beloved or terrible—that comes back to haunt the mind—life experiences so charged with emotion that they make an indelible impression on the brain and compel it to repetition.

  The emotions here can be of various kinds: grief or longing for a loved person or place from which death or exile or the passage of time has separated one; terror, horror, anguish, or dread following deeply traumatic, ego-threatening or life-threatening events. Such hallucinations may also be provoked by overwhelming guilt for a crime or sin that, perhaps belatedly, the conscience cannot tolerate. Hallucinations of ghosts—revenant spirits of the dead—are especially associated with violent death and guilt.

  Stories of such hauntings and hallucinations have a substantial place in the myths and literature of every culture. Thus Hamlet’s murdered father appears to him (“In my mind’s eye, Horatio”) to tell him how he was murdered and must be avenged. And when Macbeth is plotting the murder of King Duncan, he sees a dagger in midair, a symbol of his intention and an incitement to action. Later, after he has had Banquo killed for threatening to expose him, he has hallucinations of Banquo’s ghost; while Lady Macbeth, who has smeared Duncan’s blood over his slain grooms, “sees” the king’s blood and smells it, ineradicable, on her hands.1

  Any consuming passion or threat may lead to hallucinations in which an idea and an intense emotion are embedded. Especially common are hallucinations engendered by loss and grief—particularly following the death of a spouse after decades of togetherness and marriage. Losing a parent, a spouse, or a child is losing a part of oneself; and bereavement causes a sudden hole in one’s life, a hole which—somehow—must be filled. This presents a cognitive problem and a perceptual one as well as an emotional one, and a painful longing for reality to be otherwise.

  I never experienced hallucinations after the deaths of my parents or my three brothers, though I often dreamt of them. But the first and most painful of these losses was the sudden death of my mother in 1972, and this led to persistent illusions over a period of months, when I would mistake other people in the street for her. There was always, I think, some similarity of appearance and carriage behind these illusions, and part of me, I suspect, was hyper-alert, unconsciously searching for my lost parent.

  Sometimes bereavement hallucinations take the form of a voice. Marion C., a psychoanalyst, wrote to me about “hearing” the voice (and, on a subsequent occasion, the laugh) of her dead husband:

  One evening I came home from work as always to our big empty house. Usually at that hour Paul would have been at his electronic chessboard playing over the game in the New York Times. His table was out of sight of the foyer, but he greeted me in his familiar way: “Hello! You’re back! Hi!” … His voice was clear and strong and true; just the way it was when he was well. I “heard” it. It was as if he were actually at his chess table and actually greeting me once more. The other part was that, as I said, I couldn’t see him from the foyer, yet I did. I “saw” him, I “saw” the expression on his face, I “saw” how he moved the pieces, I “saw” him greet me. That part was like one sees in a dream: as if I were seeing a picture or a movie of an event. But the speech was live and real.

  Silas Weir Mitchell, working with soldiers who had lost limbs in the Civil War, was the first to understand the neurological nature of phantom limbs—they had previously been regarded, if at all, as a sort of bereavement hallucination. By a curious irony, Mitchell himself suffered a bereavement hallucination following the sudden death of a very close friend, as Jerome Schneck described in a 1989 article:

  A reporter brought the unexpected news one morning and Mitchell, greatly shaken, went up to tell his wife. On the way back downstairs he had an odd experience: he could see the face of Brooks, larger than life, smiling, and very distinct, yet looking as if it were made of dewy gossamer. When he looked down, the vision disappeared, but for ten days he could see it a little above his head to the left.

  Bereavement hallucinations, deeply tied to emotional needs and feelings, tend to be unforgettable, as Elinor S., a sculptor and printmaker, wrote to me:

  When I was fourteen years old, my parents, brother and I were spending the summer at my grandparents’ house as we had done for many previous years. My grandfather had died the winter before.

  We were in the kitchen, my grandmother was at the sink, my mother was helping and I was still finishing dinner at the kitchen table, facing the back porch door. My grandfather walked in and I was so happy to see him that I got up to meet him. I said, “Grampa,” and as I moved towards him, he suddenly wasn’t there. My grandmother was visibly upset, and I thought she might have been angry with me because of her expression. I said to my mother that I had really seen him clearly, and she said that I had seen him because I wanted to. I hadn’t been consciously thinking of him and still do not understand how I could have seen him so clearly.

  I am now seventy-six years of age and still remember the incident and have never experienced anything similar.

  Elizabeth J. wrote to me about a grief hallucination experienced by her young son:

  My husband died thirty years ago after a long illness. My son was nine years old at the time; he and his dad ran together on a regular basis. A few months after my husband’s death, my son came to me and said that he sometimes saw his father running past our home in his yellow running shorts (his usual running attire). At the time, we were in family grief counselling, and when I described my son’s experience, the counsellor did attribute the hallucinations to a neurologic response to grief. This was comforting to us, and I still have the yellow running shorts.

  A general practitioner in Wales, W. D. Rees, interviewed nearly three hundred recently bereft people and found that almost half of them had had illusions or full-fledged hallucinations of a dead spouse. These could be visual, auditory, or both—some of the people interviewed enjoyed conversations with their hallucinated spouses. The likelihood of such hallucinations increased with the length of marriage, and they might persist for months or even years. Rees considered these hallucinations to be normal and even helpful in the mourning process.

  For Susan M., bereavement stimulated a particularly vivid, multisensory experience a few hours after her mother died: “I heard the squeaking of the wheels of her walker in the hallway. She walked into the room shortly afterward and sat down on the bed next to me. I could feel her sit down on the mattress. I spoke to her and said I thought she had died. I don’t remember exactly what she said in return—something about checking in with me. All I know is I could feel her there and it was frightening but also comforting.”

  Ray P. wrote to me after his father died at the age of eighty-five, following a heart operation. Although Ray had rushed to the hospital, his father had already lapsed into a coma. An hour before his father died, Ray whispered to him: “Dad, it’s Ray. I’ll take care of mom. Don’t worry, everything is going to be alright.” A few nights later
, Ray wrote, he was awakened by an apparition:

  I awoke in the night. I did not feel groggy or disoriented and my thoughts and vision were clear. I saw someone sitting on the corner of my bed. It was my Dad, wearing his khaki slacks and tan polo shirt. I was lucid enough to wonder initially if this could be a dream but I was certainly awake. He was opaque, not ethereal in any way, the nighttime Baltimore light pollution in the window behind him did not show through. He sat there for a moment and then said—did he speak or just convey the thought?—“Everything is all right.”

  I turned and swung my feet to the floor. When I looked [back toward] him, he was gone. I stood and went to the bathroom, got a drink of water, and went back to bed. My dad never returned. I do not know whether this was a hallucination or something else, but since I provisionally do not believe in the paranormal, it must have been.2

  The hallucinations of grief may sometimes take a less benign form. Christopher Baethge, a psychiatrist, has written about two mothers who lost young children in a particularly traumatic way. Both had multisensory hallucinations of their dead daughters—seeing them, hearing them, smelling them, being touched by them. And both were driven to delusional, otherworldly explanations of their hallucinations: one believed that “this was her daughter’s attempt to establish contact with her from another world, a world in which her daughter continues to exist”; the other heard her daughter cry out, “Mamma, don’t be afraid, I’ll come back.”3

  Recently I tripped over a box of books in my office, fell headlong, and broke a hip. This seemed to happen in slow motion. I thought, I have plenty of time to put out my arm to break the fall, but then—suddenly—I was on the floor, and as I hit, I felt the crunch in my hip. With near-hallucinatory vividness, in the next few weeks, I reexperienced my fall; it replayed itself in my mind and body. For two months I avoided the office, the place where I had fallen, because it provoked this quasi-hallucination of falling and the crunch of breaking bone. This is one example—a trivial one, perhaps—of a reaction to trauma, a mild traumatic stress syndrome. It is largely resolved now, but it will, I suspect, lurk in the depths as a traumatic memory that may be reactivated under certain conditions for the rest of my life.