Bicameral Mind -- True / Partially True/ Totally False?

[INRM]

I've heard this thing about some guy who wrote about "The Bicameral mind" about how just a few thousand years ago, people's brains operated far more independant of each other, and one of the effects was that people heard-voices which they thought was God commanding them, but it was through the right side of the brain signalling Wernicke's area or something, and people didn't have the degree of insight as now, and even saw visions more commonly.

And due to evolutionary changes, and improved intelligence, this characteristic went away and modern day man came to be, at least that's how I remember it?

Is this true, partially true, or outright false? Also, with other mammals, particulary monkeys, especially any species particularly close to humans, does this happen where the wrong side dominates, and stuff like this happens?

INRM

[rastamonte]

I have this book, and read it from cover to cover.
Julian Jaynes
The Origin of Consciousness in the Breakdown of the Bicameral Mind.
I don't know if it is true, but it is a fascinating idea.

[andyandy]

i think God-visions were just magic mushroom hallucinations :)

[blutoski]

As rastamonte points out, this is Jaynes' theory. I read the book twenty years ago, found the reasoning questionable, and have since concluded that it borders on quackery.

Jaynes' strongest arguments are based on literature, rather than actual history or physical evidence. His arguments are subject to - among other things - our lack of understanding of period colloquialisms, the reliability of our translations, and the interpretation of the 'meaning' of text when the authors are unavailable to confirm our assumptions.

His predictions about locality and hallucination also contradict much of contemporary psychiatric physiology - audiohallucinations appear to manifest symmetrically in the frontal lobe just as often as anywhere else.

[LostAngeles]

It's interesting, but my first inclination would be to question about the food, because I think there's a particular form of mold (ergot?) that can induce hallucination. Considering food presevation back then wasn't the greatest, I'd look at any possible ingestable hallucinatory substances first, esp. if as others have said it does contradict what we currently know about the brain.

(Not saying, of course, that that couldn't ever be overturned, but for now, it looks unlikely)

[polkablues]

I could imagine a scenario in which, around the time of the inception of spoken language (obviously quite a bit earlier than what Jaynes references), there certainly could have been some confusion as the human brain adapted to thinking in language as opposed to merely image and abstraction. A thought-of word or phrase, to a brain not fully evolved to process it, could conceivably be mistaken for a message from an outside entity.

[PixyMisa]

As rastamonte points out, this is Jaynes' theory. I read the book twenty years ago, found the reasoning questionable, and have since concluded that it borders on quackery.

I'd say say it's well across the border, myself.

Jaynes' strongest arguments are based on literature, rather than actual history or physical evidence. His arguments are subject to - among other things - our lack of understanding of period colloquialisms, the reliability of our translations, and the interpretation of the 'meaning' of text when the authors are unavailable to confirm our assumptions.

Yep.

I've read Homer. Not in the original Greek, okay. But in respected translations. There is nothing at all in there to suggest that these are anything other than modern people in a fictionalised account.

People make up exactly the same type of story today. People believe exactly the same type of story today.

You can support any theory if you use your personal interpretation of selected literature as your evidence. It's just not actually worth anything as evidence.

[Dancing David]

I've heard this thing about some guy who wrote about "The Bicameral mind" about how just a few thousand years ago, people's brains operated far more independant of each other, and one of the effects was that people heard-voices which they thought was God commanding them, but it was through the right side of the brain signalling Wernicke's area or something, and people didn't have the degree of insight as now, and even saw visions more commonly.

And due to evolutionary changes, and improved intelligence, this characteristic went away and modern day man came to be, at least that's how I remember it?

Is this true, partially true, or outright false? Also, with other mammals, particulary monkeys, especially any species particularly close to humans, does this happen where the wrong side dominates, and stuff like this happens?

INRM

I am sceptical. evolution does not occue in such a short time frame generaly. Voices can be caused by a number of different causes, seizures, psychosis, ingestion of psychomimetic substances.

Ther two sides communicate through the corpus collosum. I don't know if the right side can directly contact the left motor strip.

Temporal lobe seizures and psychosis are most likely the culprits, besides starvation or ergotine(and other kinds) poisoning.

[MRC_Hans]

I think that various parts of the human population (what we sometimes call races) have a divergence point that is much earlier than a few thousand years. Since we all have the same type of brain, any evolutionary changes must have occurred much earlier, otherwise it would't be so evenly distributed.

I think the tendency for earlier people to believe more readily in the supernatural is to be explained by the fact that the scientific mindset is fairly recent. Although ancient cultures did employ scientific thinking, they mixed it with belief systems. There was not our modern way of distinguishing between knowledge-based and belief based thoughts (actually, to a considerable portion of the population, there still isn't).

Our present quest to separate belief and knowledge comes, IMHO, from the notion that all is, at least in principle, knowable. While we have moved away from the 19th century notion that science will soon have discovered everything there is to discover, we are still assuming that there is no limit to what we can potentially discover. Thus, we see the need to separate belief from knowledge.

Hans

[Zoroaster]

I have an avid interest in Jaynes' theory. I definitely think it needs major adjustments in terms of its time frame and much further study but it should not be thrown out completely. If anyone else is interested there is a new (2007) book out edited by Marcel Kujisten consisting of essays about Jaynes' theory called "Reflections on the Dawn of Consciousness". There is also a forum similar to this one which would welcome skeptical comments and inquiries from those who have read Jaynes' original book in its entirety. I can't post links but its at the Julian Jaynes Society Forum website.

As an atheist I feel that there is not sufficient inquiry into why religion occurs and with so many universal beliefs e.g. spirits, ghosts, gods, little people, voices, idolatry and possession. Jaynes' theory begins to put these together in a meaningful way. That does not mean it is right and much of it is untestable. My current viewpoint is that gives a valuable way of looking at the past and the possible development of religion and schizophrenia. I find that looking at ancient literature and archeology with this information in mind is like looking at nature with the theory of natural selection in mind that is so far I have found nothing to contradict it and it has made sense out of things that were otherwise unexplainable to me.

[Dancing David]

Schizophrenia is not caused by the bicameral mind or the development of language. Schizophrenia is caused by internal events that the brain 'hears', they are not loud thoughts. They are internal stimuli, they are not generated by the language center as far as I know (I will have to check if the occur in the auditory cortex or the language strip). People can also hallucinate noises.

He is on the wrong track, if he was really interested he would study delusion and memory. It might appear that the author is placing too much emphasis on the development of language as the defining characteristic of humans. While it is a very useful trait, in terms of evolution it is likely a late development. The wiring of memory and belief is much more important to the conflated idea of consciousness. (IE Delusions)

There are some strong reasons that people find religion useful and searching for these high level abstractions might be foolish:
1. Associative learning.
2. Confirmation bias.
3. Emotional and intuitive reasoning.
4. Pattern recognition, actually part of 1.
5. Social and cultural transmission.

ETA:

Sorry Zoraster, I did a quick search of schizophrenia research sites and none of them had any links to the phrase bicameral mind. Lots of links in 'inhibitory centers' and the like, but nothing to support this theory.

[INRM]

One thing that I remembered odd about Bicameral Mind was this...

Why did earlier writings prior to Homer have no introspection in the writings which later writings did?

[Zoroaster]

Schizophrenia is not caused by the bicameral mind or the development of language. Schizophrenia is caused by internal events that the brain 'hears', they are not loud thoughts. They are internal stimuli, they are not generated by the language center as far as I know (I will have to check if the occur in the auditory cortex or the language strip). People can also hallucinate noises.

He is on the wrong track, if he was really interested he would study delusion and memory. It might appear that the author is placing too much emphasis on the development of language as the defining characteristic of humans. While it is a very useful trait, in terms of evolution it is likely a late development. The wiring of memory and belief is much more important to the conflated idea of consciousness. (IE Delusions)

There are some strong reasons that people find religion useful and searching for these high level abstractions might be foolish:
1. Associative learning.
2. Confirmation bias.
3. Emotional and intuitive reasoning.
4. Pattern recognition, actually part of 1.
5. Social and cultural transmission.

ETA:

Sorry Zoraster, I did a quick search of schizophrenia research sites and none of them had any links to the phrase bicameral mind. Lots of links in 'inhibitory centers' and the like, but nothing to support this theory.

I was not trying to state that there is a cause and effect relationship between schizophrenia and "the Bicameral mind" (Jaynes would say that schizophrenia is the surviving vestige of the bicameral mind.) and I understand completely that Jaynes theories are widely rejected. However see if you might agree with some of these statements.

1. Old testament descriptions of prophets seem like they may be descriptions of those who would be called schizophrenic today.

2. Modern schizophrenics often equate the voices that they hear to gods or spirits and are sometimes compelled to obey the voices.

3. Religious use of idols and the belief that they once spoke can be found in the history of a surprising number of cultures.

Just because you agree with some or all of these statements, does not, of course, mean you agree with Jaynes, but these are the kind of things that fit together much better if you grant some of Jaynes' theory. I am not an expert on the brain but there are some who have confirmed the possibility of voice hallucinations originating in the right temporal lobe. (Michael Persinger - Neuropsychological Bases for God Beliefs)

As far is "if he was really interested" goes, Jaynes dedicated his adult life to understanding consciousness. I think he was really interested.

My main frustration with the outright rejection of Jaynes' theory is that it is often done without a reasonable attempt to understand a very complex and nuanced idea. Also, as he states in the preface to the second edition (paraphrasing) his theory is not one that crumbles to bits just because one piece of it is proven inaccurate.

[INRM]

What does Conflated mean?

INRM

[Jeff Corey]

Just throw in the spurs.

[PixyMisa]

One thing that I remembered odd about Bicameral Mind was this...

Why did earlier writings prior to Homer have no introspection in the writings which later writings did?
What gives you that idea? The Epic of Gilgamesh is the oldest surviving story we have, and it's deeply introspective.

[PixyMisa]

1. Old testament descriptions of prophets seem like they may be descriptions of those who would be called schizophrenic today.

2. Modern schizophrenics often equate the voices that they hear to gods or spirits and are sometimes compelled to obey the voices.

3. Religious use of idols and the belief that they once spoke can be found in the history of a surprising number of cultures.
All of these are perfectly fine.

The problem with Jaynes' theory is that this still happens today. If Jaynes were right, it would have stopped happening when the bicameral mind "broke down", but instead we find that people are people, as they have always been.

Just because you agree with some or all of these statements, does not, of course, mean you agree with Jaynes, but these are the kind of things that fit together much better if you grant some of Jaynes' theory.Why? How? They are all perfectly reasonable even if you utterly reject Jaynes' theory.

I am not an expert on the brain but there are some who have confirmed the possibility of voice hallucinations originating in the right temporal lobe. (Michael Persinger - Neuropsychological Bases for God Beliefs)Yeah, but that doesn't support Jaynes' theory, because there's no reason to believe that modern humans are any different in that respect from people of 3000 or 5000 years ago.

My main frustration with the outright rejection of Jaynes' theory is that it is often done without a reasonable attempt to understand a very complex and nuanced idea. Also, as he states in the preface to the second edition (paraphrasing) his theory is not one that crumbles to bits just because one piece of it is proven inaccurate.How is it reasonable? As I pointed out last year, all it is, is literary criticism run amok.

[Dancing David]

I was not trying to state that there is a cause and effect relationship between schizophrenia and "the Bicameral mind" (Jaynes would say that schizophrenia is the surviving vestige of the bicameral mind.) and I understand completely that Jaynes theories are widely rejected. However see if you might agree with some of these statements.

1. Old testament descriptions of prophets seem like they may be descriptions of those who would be called schizophrenic today.

Not really, a person with untreated scizophrenia would be very unlikely to make it to the point of getting a following. The vast majority of schizophrenias show affective flattening and are severely debilitated they would be unlikely to survive.

The point is that you do not need this high level abstracted theory to explain why people here voices. that is why schizophrenia research would be a clue. No mention of the bicameral mind.

The role of prophets would be a complex social and political one. I would not discount the role of mentali illness but the split brain thing is interesting. It does not produce hallucinations.

2. Modern schizophrenics often equate the voices that they hear to gods or spirits and are sometimes compelled to obey the voices.

They also think thier neighbors are hiding in the walls, and that Ted Kennedy is watching them through the electrical wiring.

And again, command hallucinations do not need to high level abstracted theory to exist. I am also not sure people are compelled to follow command hallucinations the way an individual with OCD follows compulsions.


3. Religious use of idols and the belief that they once spoke can be found in the history of a surprising number of cultures.

Considering 75% of United Statesers feel they have talked to god that is not suprising, nor would outright chicanery be excluded.


Just because you agree with some or all of these statements, does not, of course, mean you agree with Jaynes, but these are the kind of things that fit together much better if you grant some of Jaynes' theory. I am not an expert on the brain but there are some who have confirmed the possibility of voice hallucinations originating in the right temporal lobe. (Michael Persinger - Neuropsychological Bases for God Beliefs)

As far is "if he was really interested" goes, Jaynes dedicated his adult life to understanding consciousness. I think he was really interested.

My main frustration with the outright rejection of Jaynes' theory is that it is often done without a reasonable attempt to understand a very complex and nuanced idea. Also, as he states in the preface to the second edition (paraphrasing) his theory is not one that crumbles to bits just because one piece of it is proven inaccurate.

My issue is that is a high level abstratcetd theory, it is not based upon the simple biomechanics of the way the brain functions, it is mainly speculative and perhaps was started before the advent of modern neurobiology.

As in other sciences, start with the simple and try to keep it simple. I am not condemning it wholesale, just pointing out it is ,um, very speculative.

the study of consciousness is best understood through reduction to biological processes.

[Dancing David]

What does Conflated mean?

INRM

To join together , sometimes in a confused and misleading fashion.

http://www.bartleby.com/61/28/C0562800.html
SYLLABICATION: con·flate
PRONUNCIATION: kn-flt
TRANSITIVE VERB: Inflected forms: con·flat·ed, con·flat·ing, con·flates
1. To bring together; meld or fuse: “The problems [with the biopic] include . . . dates moved around, lovers deleted, many characters conflated into one” (Ty Burr, Entertainment Weekly May 18, 1994).
2. To combine (two variant texts, for example) into one whole.
ETYMOLOGY: Latin cnflre, cnflt- : com-, com- + flre, to blow; see bhl- in Appendix I.
OTHER FORMS: con·flation —NOUN

[Bikewer]

I've read a couple of Oliver Sacks' books on psychology and mental oddities, and it's apparent that most of these sorts of phenomena are pretty well described in psychological literature.
Mostly having to do with temporal-lobe disturbances; the temporal being strongly connected to our perception of reality.
Hallucinations of all sorts, time anomalies, "dual" perception anomalies... All due to lesions, temporal epilepsy, and other disturbances.

[Zeuzzz]

Bump to this thread. Interesting stuff this.

What does Conflated mean?

INRM


Sort of to merge, usually means that if your conflating the distinction between two things you getting them muddled up. Random Example: When poloticians say "Iran strongly supports they development of nuclear weapons", they are conflating Iran wanting to be a nuclear power with them wanting nuclear weapons.



...So, whats the verdict on Mr Jayne's theory? Richard dawkins said "It is one of those books that is either complete rubbish or a work of consummate genius, nothing in between! Probably the former, but I'm hedging my bets."

Its obviously not complete woo-woo. I think that much of what he attributes to hallucinations can be accounted for by previously higher amounts of natural psychoactives in humans diets (the extremely potent DMT in grass [and thousands of other species] being an obvious one) or to maybe mass hereditory mental illness/schizophrenia in general in the human race, which has since been selected out over time via standard evolutionary processes.

Jaynes inferred that these "voices" came from the right brain counterparts of the left brain language centres—specifically, the counterparts to Wernicke's area and Broca's area. These regions are somewhat dormant in the right brains of most modern humans, but Jaynes noted that some studies show that auditory hallucinations correspond to increased activity in these areas of the brain.

http://en.wikipedia.org/wiki/Bicameral_mind
Responses

Jaynes's hypothesis remains controversial and has lacked discussion by mainstream academics. The few criticisms that have been made include:

* the idea that consciousness is a cultural construction is hard to take seriously[9]
* the conclusions Jaynes drew had no basis in neuropsychiatric fact at that time[10]
* difficulty with the idea that auditory hallucinations played a significant role in a previous human mentality[11]

Richard Dawkins discussed Jaynes's theory in his recent book The God Delusion. In his chapter on the roots of religion, Dawkins writes: "It is one of those books that is either complete rubbish or a work of consummate genius, nothing in between! Probably the former, but I'm hedging my bets."[12] Many considered Jaynes's hypothesis worthy and offer conditional support, arguing the notion deserves further study.[13][14]

In a 1987 letter to the American Journal of Psychiatry, Dr. H. Steven Moffic questioned why Jaynes's theory was left out of a discussion on auditory hallucinations by Drs. Asaad and Shapiro. In response, Drs. Assad and Shapiro wrote, "…Jaynes' hypothesis makes for interesting reading and stimulates much thought in the receptive reader. It does not, however, adequately explain one of the central mysteries of madness: hallucination."[15]


So, whats the main fatal flaw in his work?

I know theres plently of one liners he says that people can pick up on as being woo (eg "guided by mental commands believed to be issued by external "gods", which sounds like major woo-woo, until you actually read why he says this and find out this is not his personal view), but I'm trying to look at the bigger picture and this theory in general.

[Zeuzzz]

I've read a couple of Oliver Sacks' books on psychology and mental oddities, and it's apparent that most of these sorts of phenomena are pretty well described in psychological literature.



Yeah his books are brilliant. Always stays scientific in what he addresses, while emphasising the many inexplicabilities of human consciousness's role in creating our reality though our sense (mainly sound and music). If you like his stuff then you'll also like "This Is Your Brain on Music: The Science of a Human Obsession" by Letvin, though it doesn't quite compare with Sach's material. http://www.amazon.com/This-Your-Brain-Music-Obsession/dp/0525949690

Love this review: There are questions that are too big for science; are there gods, for instance, or what is love? And maybe we will never fully find out scientifically why music does what it does and why we care about it so. But for many reasons, music ought to be a profitable subject for scientific enquiry. It is, as Pythagoras knew, an activity strongly rooted in mathematics, and the physics of music is fairly well understood. It is as universal as language; all human cultures have some sort of music, indicating it does something indispensable. And we are increasingly able to figure out, with our sophisticated brain imaging gadgets, what brains do when they hear or think about music. The neuroscience of music is the area of expertise of Daniel J. Levitin, and he writes of it in _This Is Your Brain on Music: The Science of a Human Obsession_ (Dutton), a fascinating account of current music psychology. [....]

[blutoski]

One thing that I remembered odd about Bicameral Mind was this...

Why did earlier writings prior to Homer have no introspection in the writings which later writings did?

Exactly. Jaynes has simply ignored the possibility that Homer developed a new style.

Authors throughout the ages have had different styles. It's really pushing it to extrapolate mental processes from compositions.

Jaynes didn't seem to be interested in comparing peers or predecessors in other cultures, which is a blatant omission that led me to ultimately dismiss his work as somewhere between half-baked and crackpot.

[ben m]

I've read the first part of Jaynes' book, where he discusses what it might mean to have a "bicameral mind" and how that might develop into consciousness. I haven't read the full literary evidence.

In my view, Jaynes brings up a very interesting evidentiary question: "How do we know that the people of (whatever civilization/era) were conscious?" Jaynes presents a plausible-ish hypothesis for a sort of mind which could think clearly enough to (e.g.) produce stone tools, ritually bury its dead, farm, and even erect Stonehenge, without yet being conscious; by doing this Jaynes successfully (IMO) refutes any argument that complex archaeological traces must necessarily imply consciousness.

This is, IMO, separate from the more specific argument that "the origin of consciousness was somewhere between Gilgamesh and the Iliad"; I can't say too much because I haven't read Jayne's argument myself. No one I know finds it convincing.

[TX50]

Exactly. Jaynes has simply ignored the possibility that Homer developed a new style.


It's now widely held that the Homeric poems, in the form in which we have
them today, actually date from no earlier than the 5th century BCE, with
some elements and additions of even more recent date than that. The story
elements are definitely much older but the works as known today are
versions of earlier poems written and compiled in the 5th century (Plato is
the first ancient source who quotes Homer as it is known today). So if
Jaynes is building parts of his theory on philological or stylistic details in
Homer then he's probably barking up the wrong tree.

[PixyMisa]

Exactly. Jaynes has simply ignored the possibility that Homer developed a new style.
Well, since it's historically unlikely that the Iliad and Odyssey were written down by the same man, differences in style are to be expected. ;)

The best proposal I've seen - one that doesn't really rescue Jaynes, but makes sense of why he got it wrong - is that the pre-Odyssey Greek language had no word for consciousness, so it wasn't discussed directly, so the literary forms were different.

Not sure how accurate that is, but it's at least plausible.

[PixyMisa]

In my view, Jaynes brings up a very interesting evidentiary question: "How do we know that the people of (whatever civilization/era) were conscious?" Jaynes presents a plausible-ish hypothesis for a sort of mind which could think clearly enough to (e.g.) produce stone tools, ritually bury its dead, farm, and even erect Stonehenge, without yet being conscious; by doing this Jaynes successfully (IMO) refutes any argument that complex archaeological traces must necessarily imply consciousness.
No, sorry, you can't get there from here.

That would imply that our ancestors were P-Zombies, and that way lies madness (and Religion & Philosophy - same thing, really).

We know they were conscious because they were physically just the same as us and acted just the same as us.

[ben m]

No, sorry, you can't get there from here.

That would imply that our ancestors were P-Zombies, and that way lies madness (and Religion & Philosophy - same thing, really).

We know they were conscious because they were physically just the same as us and acted just the same as us.

Given that philosophers are not, to my knowledge, absolutely sure that they could identify a p-zombie right now, I don't see what claims we can make about (e.g.) Otzi the Ice Man---it's easy to imagine that he acted the same as us, but our data is pretty scanty and we're analyzing that data with brains that are prone to making the pathetic fallacy.

But I've bumped up against the edge of my learning and I should really retreat. I just think it's a neat hypothesis, and I'm interested in what everyone else has to say about it.

[PixyMisa]

Given that philosophers are not, to my knowledge, absolutely sure that they could identify a p-zombie right now, I don't see what claims we can make about (e.g.) Otzi the Ice Man---it's easy to imagine that he acted the same as us, but our data is pretty scanty and we're analyzing that data with brains that are prone to making the pathetic fallacy.
Right. The other way to look at it is that our ancestors were P-Zombies - and so are we.

We don't have FMRI scans of Gilgamesh or Khufu, but apart from that, the evidence that bronze-age people were conscious is pretty much the same as the evidence we have today.

[ddt]

Well, since it's historically unlikely that the Iliad and Odyssey were written down by the same man, differences in style are to be expected. ;)
When they were written down - traditionally dated in the reign of Peisistratos, mid 6th C. BC - they had been handed down orally for centuries, probably by itinerant bards. Moreover, they are not written in one specific Greek dialect, but in a mixture of various dialects. That pretty much excludes a single author.


The best proposal I've seen - one that doesn't really rescue Jaynes, but makes sense of why he got it wrong - is that the pre-Odyssey Greek language had no word for consciousness, so it wasn't discussed directly, so the literary forms were different.
What word would that be? Or could anyone give two typical passages which would illustrate the difference Jaynes sees in both works?

(First time I heard of Jaynes, but it's a good excuse to pick up my copy of Homer :))

[HansMustermann]

Not really, a person with untreated scizophrenia would be very unlikely to make it to the point of getting a following. The vast majority of schizophrenias show affective flattening and are severely debilitated they would be unlikely to survive.

There are however several different kinds of schizophrenias. Paranoid schizophrenia can often have no other symptoms except hearing voices and/or seeing things for several years.

I actually knew someone who apparently was well into the stage of having vivid halucinations, but I wouldn't have guessed until she decided to tell me about it. She seemed a bit too superstitious, but then lots of people are. Turned out she was that interested in ghosts and spiritism because she actually was seeing ghosts. But anyway, she wasn't too disabled to work or to have a seemingly normal life otherwise.

So basically your sentence is technically true, but in the same way as saying "the vast majority of people with untreated cancer will die in a couple of years." Not the ones with, say, prostate cancer.

[HansMustermann]

It's interesting, but my first inclination would be to question about the food, because I think there's a particular form of mold (ergot?) that can induce hallucination. Considering food presevation back then wasn't the greatest, I'd look at any possible ingestable hallucinatory substances first, esp. if as others have said it does contradict what we currently know about the brain.

Indeed, the active substance of Ergot has identical effects to LSD -- and also infinitesimal amounts are enough to cause quite the hallucinations -- plus a nasty vasoconstriction effect. Many of those who had an Ergot-induced trip would then get gangrene in some limb, but then again many would not.

Especially during the middle ages, there are enough documented cases of city-wide Ergot trips. (Again, bear in mind that it didn't take too much Ergot to contaminate the flour from a mill for that day.) People spontaneously started dancing in the streets and having mystical visions and stuff.

They actually had an order of monks who tried to save the people who got the really bad end of that vasoconstriction, so it couldn't have been too rare.

Again, bear in mind that many LSD trips are reported as mystical revelations or experiences. The difference being that if you took LSD, you'd have good reason to think that your visions came from the LSD. If you were a peasant and don't remember doing anything more suspicious than eating some bread -- same as on any other day -- you might be more inclined to think that you had a genuine religious vision.

You also have to bear in mind that at least in ancient Messopotamia, as their soil became more and more salty over the millenia, there was an increase in the amount of rye and barley cultivated instead of wheat.

[Ekinodum]

I read The Evolution of Conciousness in the Breakdown of the Bicameral Mind when it came out, mostly at the insistence of some friends that were very impressed. I recall being intrigued by some parts of the book (the notion that the only time you are truly concious is when you are actively contemplating your own conciousness, for instance). One of my friends was (and still is) enamored with Philosophy, and was impressed by the philosophical ramifications.
But then it became apparent that one of the central themes of the book was the idea that conciousness arose as a result of some kind of relatively sudden and recent change, in Europe, as I recall.
So it became a scientific (and testable) hypothesis.
I thought that an easy way to test this would be to see if other peoples besides those of relatively recent European descent (American Indians, Australian Aboriginals, and those of Eastern European descent, and others) also exhibited conciousness.
It was an easy thought experiment, and at that point I discarded the book, and lamented the time I wasted reading it.
The book had much longer legs than it deserved.

[Beerina]

As rastamonte points out, this is Jaynes' theory. I read the book twenty years ago, found the reasoning questionable, and have since concluded that it borders on quackery.

Jaynes' strongest arguments are based on literature, rather than actual history or physical evidence. His arguments are subject to - among other things - our lack of understanding of period colloquialisms, the reliability of our translations, and the interpretation of the 'meaning' of text when the authors are unavailable to confirm our assumptions.

It may also leave out that writing style may not have just popped in place, fully formed. I.e. the kinds of writing of which he speaks, which supposedly suggest two independently conscious minds in the same skull, may just be the way people wrote back then, the way paintings and sculptures go through different period styles. And, yes, it could be global-ish, even with de facto permanent separation of populations, as more modern writing style may have been something that evolved. One would look at a caveman painting, then something in the Louvre, and think...what? That a caveman had a different brain and thus painted differently?





His ideas are fascinating because how consciousness arose is one of the two Big Questions that science is still grappling with. We know, thanks to hemispherectomies, accidents, and birth defects, that one lobe is sufficient for consciousness. So in theory you could have two simultaneously in the skull at certain points, or perhaps at some point in the past. Exactly how these manifest themselves and appear "merged" remains to be seen. But a lot more work needs to be done. Francis Crick (http://www.klab.caltech.edu/~koch/crick-koch-cc-97.html), et al., believe the time for philosophizing is over and the time for the scientific attack is now. And only once how the brain works w.r.t. to conscious perceptions is fully mapped, only then can we begin working on the subjective experience of consciousness. Only then will we be able to see what is "missing" and may require an extension to physics as we know it.