What We Talk About When We Talk About Consciousness
One of Oliver Sacks’ last popular books, published in 2012, was about hallucinations, titled, appropriately, Hallucinations. In it, he takes a look at numerous types of hallucinatory phenomena—hallucinations among the blind (Charles Bonnett Syndrome); sensory deprivation; delirium; grieving; Post-traumatic Stress Disorder; epilepsy; migraines; hypnagogia; Parkinson’s Disease, psychedelic usage; religious ecstasy; and so on.
There are a number of interesting facts presented about auditory hallucinations.
One is the fact that although auditory hallucination of voices is indeed indicative of schizophrenia, in most cases auditory hallucinations are experienced by perfectly normal people with no other signs of mental illness.
Sacks begins his chapter on auditory hallucinations by describing an experiment in 1973 where eight “fake” patients went to mental hospitals complaining of hearing voices, but displaying no other signs of mental illness or distress. In each case, they were diagnosed as schizophrenic (one was considered manic-depressive), committed to a facility for two months, and given anti-psychotic medication (which they obviously did not take). While committed, they even openly took notes on their experiences, yet none of the doctors or staff ever wised up to the ruse. The other patients, however, were much more perceptive. They could clearly see that the fake patients were not at all mentally ill, and even asked them, “what are you doing here?” Sacks concludes:
This experiment, designed by David Rosenhan, a Stanford psychologist (and himself a pseudopatient), emphasized, among other things, that the single symptom of “hearing voices” could suffice for an immediate, categorical diagnosis of schizophrenia even in the absence of any other symptoms or abnormalities of behavior. Psychiatry, and society in general, had been subverted by the almost axiomatic belief that “hearing voices” spelled madness and never occurred except in the context of severe mental disturbance. p. 54
While people often mischaracterize Jaynes’ theory as “everyone in the past was schizophrenic,” it turns out that even today most voices are heard by perfectly normal, otherwise rational, sane, high-functioning people. This has been recognized for over a century in medical literature:
“Hallucinations in the sane” were well recognized in the nineteenth century, and with the rise of neurology, people sought to understand more clearly what caused them. In England in the 1880s, the Society for Psychical Research was founded to collect and investigate reports of apparitions or hallucinations, especially those of the bereaved, and many eminent scientists—physicians as well as physiologists and psychologists—joined the society (William James was active in the American branch)…These early researchers found that hallucinations were not uncommon among the general population…Their 1894 “International Census of Waking Hallucinations in the Sane” examined the occurrence and nature of hallucinations experienced by normal people in normal circumstances (they took care to exclude anyone with obvious medical or psychiatric problems). Seventeen thousand people were sent a single question:
“Have you ever, when believing yourself to be completely awake, had a vivid impression of seeing or being touched by a living being or inanimate object, or of hearing a voice, which impression, as far as you could discover, was not due to an external physical cause?”
More than 10 percent responded responded in the affirmative, and of those, more than a third heard voices. As John Watkins noted in his book Hearing Voices, hallucinated voices “having some kind of religious or supernatural content represented a small but significant minority of these reports.” Most of the hallucinations, however, were of a more quotidian character. pp. 56-57
While the voices heard by schizophrenics are often threatening and controlling, the voices heard by most people do not appear to have any effect on normal functioning at all.
The voices that are sometimes heard by people with schizophrenia tend to be accusing, threatening, jeering, or persecuting. By contrast, the voices hallucinated by the “normal” are often quite unremarkable, as Daniel Smith brings out in his book Muses, Madmen, and Prophets: Hearing Voices and the Borders of Sanity. Smith’s own father and grandfather heard such voices, and they had different reactions. His father started hearing voices at the age of thirteen. Smith writes:
“These voices weren’t elaborate, and they weren’t disturbing in content. They issued simple commands. They instructed him, for instance, to move a glass from one side of the table to another or to use a particular subway turnstile. Yet in listening to them and obeying them his interior life became, by all accounts, unendurable.”
Smith’s grandfather, by contrast, was nonchalant, even playful, in regard to his hallucinatory voices. He described how he tried to use them in betting at the racetrack. (“It didn’t work, my mind was clouded with voices telling me that this horse could win or maybe this one is ready to win.”) It was much more successful when he played cards with his friends. Neither the grandfather nor the father had strong supernatural inclinations; nor did they have any significant mental illness. They just heard unremarkable voices concerned with everyday things–as do millions of others. pp. 58-59
To me, this sounds an awful lot like Jaynes’s descriptions of the reality of bicameral man doesn’t it? The voices command, and the people obey the commands. Yet they still are outwardly normal, functioning individuals. You may never know whether someone is obeying voices in their head unless they explicitly told you:
This is what Jaynes calls “bicameral mind”: one part of the brain (the “god” part) evaluates the situation and issues commands to the other part (the “man” part) in the form of auditory and, occasionally, visual hallucinations (Jaynes’ hypothesises that the god part must have been located in the right hemisphere, and the man part, in the left hemisphere of the brain). The specific shapes and “identities” of these hallucinations depend on the culture, on what Jaynes calls “collective cognitive imperative”: we see what we are taught to see, what our learned worldview tells us must be there.
Julian Jaynes and William Shakespeare on the origin of consciousness in the breakdown of bicameral mind (Sonnets in Colour)
In most of the cases described in Hallucinations, people didn’t attribute their auditory or visual hallucinations to any kind of supernatural entity or numinal experience. A few did refer to them as “guardian angels”. But what if they had grown up in a culture where this sort of thing was considered normal, if not commonplace, as was the case for most of ancient history?
Hearing voices occurs in every culture and has often been accorded great importance–the gods of Greek myth often spoke to mortals, and the gods of the great monotheistic traditions, too. Voices have been significant in this regard, perhaps more so than visions, for voices, language, can convey an explicit message or command as images alone cannot.
Until the eighteenth century, voices—like vision—were ascribed to supernatural agencies: gods or demons, angels or djinns. No doubt there was sometimes and overlap between such voices and those of psychosis or hysteria, but for the most part, voices were not regarded as pathological; if they stayed inconspicuous and private, they were simply accepted as part of human nature, part of the way it was with some people. p. 60
In the book The Master and His Emissary, Iain McGilchrist dismisses Jaynes’s theory by claiming that schizophrenia is a disease of recent vintage, and only emerged sometime around the nineteenth century. Yet, as the Jaynes foundation website points out (2.7), this is merely when the diagnosis of schizophrenia was established. Before that time, it would not have been considered pathological or a disease at all. We looked at how Akhnaten’s radical monotheism was possibly inspired by God “speaking” directly to him, issuing commands to build temples, and so forth. Certainly, he thought it was, at any rate. And he’s hardly alone. We’ve already looked at notable historical personages like Socrates, Muhammad, Joan of Arc, and Margery Kempe, and there are countless other examples. Schizophrenia is no more “new” than is PTSD, which was barely recognized until after Wold War One, where it was called “shellschock.”

Another thing Sacks points out is that command hallucinations tend to occur in stressful situations or times of extreme duress, or when one has some sort of momentous or climactic decision to make, just as Jaynes posited. In times of stress, perfectly ordinary, sane people often hear an “outside” voice coming from somewhere guiding their actions. This is, in fact, quite common. In “normal” conditions we use instinct or reflex to guide our actions. But in emergencies, we hear a voice that seems to come from somewhere outside our own consciousness:
If, as Jaynes proposes, we take the earliest texts of our civilisation as psychologically valid evidence, we begin to see a completely different mentality. In novel and stressful situations, when the power of habit doesn’t determine our actions, we rely on conscious thinking to decide what to do, but, for example, the heroes of Iliad used to receive their instructions from gods — which would appear in the times of uncertainty and stress.
Julian Jaynes and William Shakespeare on the origin of consciousness in the breakdown of bicameral mind (Sonnet in Colour)
For example, Dr. Sacks is perfectly aware that his “inner monologue” is internally generated. Yet in a stressful situation, the voice became externalized—something that seemed to speak to him from some outside source:
Talking to oneself is basic to human beings, for we are linguistic species; the great Russian psychologist Lev Vygotsky thought that inner speech was a prerequisite of all voluntary activity. I talk to myself, as many of us do, for much of the day–admonishing myself (“You fool! Where did you leave your glasses?”), encouraging myself (“You can do it!”), complaining (“Why is that car in my lane?”) and, more rarely, congratulating myself (“it’s done!”). Those voices are not externalized; I would never mistake them for the voice of God, or anyone else.
But when I was in danger once, trying to descend a mountain with a badly injured leg, I heard an inner voice that was wholly unlike my normal babble of inner speech. I had a great struggle crossing a stream with a buckled and dislocating knee. The effort left me stunned, motionless for a couple of minutes, and then a delirious languor came over me, and I thought to myself, Why not rest here? A nap maybe? This was immediately countered by a strong, clear, commanding voice, which said, “You can’t rest here—you can’t rest anywhere. You’ve got to go on. Find a place you can keep up and go on steadily.” This good voice, the Life voice, braced and resolved me. I stopped trembling and did not falter again. pp. 60-61
Sacks gives some other anecdotal examples of people under extreme duress:
Joe Simpson, climbing in the Andes, also had a catastrophic accident, falling off an ice ledge and ending up in a deep crevasse with a broken leg. He struggled to survive, as he recounted in Touching the Void–and a voice was crucial in encouraging and directing him:
“There was silence, and snow, and a clear sky empty of life, and me, sitting there, taking it all in, accepting what I must try to achieve. There were no dark forces acting against me. A voice in my head told me that this was true, cutting through the jumble in my mind with its coldly rational sound.”
“It was as if there were two minds within me arguing the toss. The *voice* was clean and sharp and commanding. It was always right, and I listened to it when it spoke and acted on its decisions. The other mind rambled out a disconnected series of images, and memories and hopes, which I attended to in a daydream state as I set about obeying the orders of the *voice*. I had to get to the glacier….The *voice* told me exactly how to go about it, and I obeyed while my other mind jumped abstractly from one idea to another…The *voice*, and the watch, urged me into motion whenever the heat from the glacier halted me in a drowsy exhausted daze. It was three o’clock—only three and a half hours of daylight left. I kept moving but soon realized that I was making ponderously slow headway. It didn’t seem to concern me that I was moving like a snail. So long as I obeyed the *voice*, then I would be all right.”
Such voices may occur with anyone in situations of extreme threat or danger. Freud heard voices on two such occasions, as he mentioned in his book On Aphasia:
“I remember having twice been in danger of my life, and each time the awareness of the danger occurred to me quite suddenly. On both occasions I felt “this was the end,” and while otherwise my inner language proceeded with only indistinct sound images and slight lip movements, in these situations of danger I heard the words as if somebody was shouting them into my ear, and at the same time I saw them as if they were printed on a piece of paper floating in the air.“
The fact that the gods tend to come to mortals in the Iliad during times of stress has been noted by author Judith Weissman, author of “Of two minds: Poets who hear voices”:
Judith Weissman, a professor of English at Syracuse University, notes that in the Iliad the gods speak directly to the characters over 30 times, often when the characters are under stress. Many of the communications are short, brief, exhortations. The most common godly command, issued when the men are fearful in battle, is to, “fight as your father did.” At one point in the Iliad, the god Apollo picks up Hektor, who has fallen in battle, and says, “So come now, and urge on your cavalry in their numbers / to drive on their horses against the hollow ships” (15.258-59)…
Personality Before the Axial Age (Psychology Today)
Hallucinations are also quite common in soldiers suffering from PTSD. If modern soldiers experience PTSD, how much more traumatic would be ancient battles, like those described so vividly in the Iliad? I can’t even imagine standing face-to-face with a foe, close enough to feel his hot breath, and having to shove a long, sharp metal object directly into his flesh without hesitation; blood gushing everywhere and viscera sliding out of his belly onto the dirt. And yet this was the reality of ancient warfare in the Bronze and Iron ages. Not to mention the various plagues, dislocations, natural disasters, invasions, and other assorted traumatic events.
People with PTSD are also prone to recurrent dreams or nightmares, often incorporating literal or somewhat disguised repetitions of the traumatic experiences. Paul Chodoff, a psychiatrist writing in 1963 about the effects of trauma in concentration camp survivors, saw such dreams as a hallmark of the syndrome and note that in a surprising number of cases, they were still occurring a decade and half after the war. The same is true of flashbacks. p. 239
Veterans with PTSD may hallucinate the voices of dying comrades, enemy soldiers, or civilians. Holmes and Tinnin, in one study, found that the hearing of intrusive voices, explicitly or implicitly accusing, affected more than 65 percent of veterans with combat PTSD. p. 237 note 4
The other very common occurrence where otherwise “sane” people will often hallucinate sounds or images is during grief and bereavement. Sometimes this is just hearing the voice of the departed person speaking to them or calling them. Sometimes they may actually see the person. And sometimes they may even carry on extended conversations with their deceased family members!
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 the grief. This was comforting to us, and I still have the yellow running shorts.” pp. 233-234
It turns out that this kind of thing is extremely common:
A general practitioner in Wales, W.D. Rees, interviewed nearly three hundred recently bereft people and found that almost half of them 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 the marriage, and they might persist for months or even years. Rees considered these hallucinations to be normal and even helpful in the mourning process. p. 234
A group of Italian psychological researchers published a paper in 2014 entitled “Post-bereavement hallucinatory experiences: A critical overview of population and clinical studies.” According to their paper, after an extensive review of peer-reviewed literature, they found that anywhere from 30 to 60 percent of grieving people experienced what they called “Post-bereavement hallucinatory experiences” (PBHEs). Is it any wonder why veneration of the dead was so common across cultures from the Old World to Africa to Asia to the Americas to Polynesia? It was almost universally assumed that the dead still existed in some way across ancient cultures. Some scholars such as Herbert Spencer posited that ancestor worship was the origin of all religious rites and practices.
What is the fundamental cause of all these aural hallucinations? As neurologist Sacks freely admits, the source of these phenomena is at present unknown and understudied. Sacks references Jaynes’s “Origin of Consciousness…” in his speculation on possible explanations:
Auditory hallucinations may be associated with abnormal activation of the primary auditory cortex; this is a subject which needs much more investigation not only in those with psychosis but in the population at large–the vast majority of studies so far have examined only auditory hallucinations in psychiatric patients.
Some researchers have proposed that auditory hallucinations result from a failure to recognize internally generated speech as one’s own (or perhaps it stems from a cross-activation with the auditory areas so that what most of us experience as our own thoughts becomes “voiced”).
Perhaps there is some sort of psychological barrier or inhibition that normally prevents most of us from “hearing” such inner voices as external. Perhaps that barrier is somehow breached or underdeveloped in those who do hear constant voices. Perhaps, however, one should invert the question–and ask why most of us do not hear voices.
In his influential 1976 book, The Origin of Consciousness in the Breakdown of the Bicameral Mind, speculated that, not so long ago, all humans heard voices–generated internally from the right hemisphere of the brain, but perceived (by the left hemisphere) as if external, and taken as direct communications from the gods. Sometime around 1000 B.C., Jaynes proposed, with the rise of modern consciousness, the voices became internalized and recognized as our own…Jaynes thought that there might be a reversion to “bicamerality” in schizophrenia and some other conditions. Some psychiatrists (such as Nasrallah, 1985) favor this idea or, at the least, the idea that the hallucinatory voices in schizophrenia emanate from the right side of the brain but are not recognized as one’s own, and are thus perceived as alien…It is clear that “hearing voices” and “auditory hallucinations” are terms that cover a variety of different phenomena. pp. 63-64
Recently, neuroscientists have hypothesized the existence of something called an “efference copy” which is made by the brain of certain types of stimulus. The presence of the effluence copy informs the brain that certain actions have originated from itself, and that subsequent inputs are self-generated. For example, the efference copy of your hand movements is what prevents you from tickling yourself. The existence of this efferance copy—or rather the lack thereof—has been postulated as the reason why schizophrenics can’t understand the voices in their heads as being their own. A temporary suppression of the efference copy may be behind why so many otherwise “sane” people often hear voices as something coming from outside their own mind.
Efference copy is a neurological phenomenon first proposed in the early 19th century in which efferent signals from the motor cortex are copied as they exit the brain and are rerouted to other areas in the sensory cortices. While originally proposed to explain the perception of stability in visual information despite constant eye movement, efference copy is now seen as essential in explaining a variety of experiences, from differentiating between exafferent and reafferant stimuli (stimulation from the environment or resulting from one’s own movements respectively) to attenuating or filtering sensation resulting from willed movement to cognitive deficits in schizophrenic patients to one’s inability to tickle one’s self.
Efference Copy – Did I Do That? Cody Buntain, University of Maryland (PDF)
I talk to myself all the time. The words I’m typing in this blog post are coming from some kind of “inner self.” But I feel like that inner voice and “me” are exactly the same, as I’m guessing you do too, and so do most of us “normal” people. But is that something inherent in the brain’s bioarchitecture, or is that something we are taught through decades of schooling and absorbing our cultural context? Might writing and education play an important role in the “breakdown” of bicameralism? We’ll take a look at that next time.
The version of bicameralism that seems most plausible to me is the one where the change is a memetic rather than evolutionary-genetic event. If it were genetic, there would still be too many populations that don’t have it, but whose members when plucked out of the wilderness and sent to university seem to think and feel and perceive the world the way the rest of us do.
But integrated, introspective consciousness could be somewhere between language and arithmetic on the list of things that the h. sapien brain has always been capable of but won’t actually do if you just have someone raised by wolves or whatnot. Language, people figure out as soon as they start living in tribes. Arithmetic comes rather later than that. If Jaynes is right, unicameral consciousness is something people figure out when they have to navigate an environment as complex as a bronze-age city, and once they have the knack they teach their kids without even thinking about it. Or other peoples’ kids, if they are e.g. missionaries.
At which point brains whose wiring is better suited to the new paradigm will have an evolutionary advantage, and there will be a genetic shift, but as a slow lagging indicator rather than a cause.
John Schilling – Comment (Slate Star Codex)
[I’m just going to drop this here—much of the cause of depression stems from negative self-talk (“It’s hopeless!;” Things will never get better;” “I’m worthless,”etc.). In such cases, this “inner voice,” rather than being encouraging, is a merciless hector to the depressed individual. As psychologists often point out to their patients, we would never talk to anyone else as callously we talk to ourselves. Why is that? And it seems interesting that there are no references to depression in bicameral civilizations as far as I know. Ancient literature is remarkably free of “despair suicides” (as opposed to suicides for other reasons such as defeat in battle or humiliation).]