I just reread Julian Jaynes’ chapter on the brain in The Origin of Consciousness in the Breakdown of the Bicameral Mind and it’s really fascinating. He raises some incredible questions. First, he notes that almost all important brain functions are represented bilaterally in the brain. This makes evolutionary sense because functional redundancy is a survival skill in the event of injury. But curiously, language is not bilaterally represented yet it is perhaps the most important function in human existence, separating us from the animals. We would not be human without it, as feral children sadly demonstrate. Moreover, the left hemisphere is often called the “dominant” hemisphere because most people are right-handed, and thus have a left-hemisphere dominance in voluntary control (and there is even a right eye field dominance).
There must be a good reason then why something as important as language wouldnt have been bilaterally represented during evolutionary development. We know from lesion studies that if we take out the Wernicke’s area in the left hemisphere during childhood, the whole mechanism of language will transfer to the right hemisphere. So it isn’t that the right hemisphere corresponding to left language areas is incapable of bilateral language redundancy, it’s that it must subserve some other function that is even more valuable for us than language. Jaynes asks, what is this function? His answer:
The selective pressures of evolution which could have brought about so mighty a result are those of the bicameral civilizations. The language of men was involved with only one hemisphere in order to leave the other free for the language of gods. (103-104)
This is Jaynes’ hypothesis of the “bicameral mind”. The bicameral mind is based on the metaphor of a divided house, like two selves housed in one brain (similar to split-brain patients). On the right side is the god-complex, grounded in the right temporal cortex. It’s function was to solve problems by synthesizing complex information and relaying linguistically-coded behavioral instructions to the other side, the mortal-complex, grounded in the left temporal cortex. The gods obeyed and the humans heard. And to hear was to obey. This function substituted for voluntary will in our preconscious ancestors.That this might be true is evidenced by the fact that the temporal lobes have their own private communication channel: the smaller anterior commissures. Moreover, articles like these:
- Auditory hallucinations and the bicameral mind
- Neuroimaging, auditory hallucinations, and the bicameral mind
- Auditory Hallucinations and the Temporal Cortical Response to Speech in Schizophrenia: A Functional Magnetic Resonance Imaging Study
- Activation of bilateral auditory cortex during verbal hallucinations in a child with schizophrenia
show that the neural substrate for schizophrenic hallucination is the the right temporal cortex, as per Jaynes’ theory.
Accordingly, we might be able to tell the following “Just So” story. First, emphasize that the first complex societies were authoritarian through and through, or at structured by a rigid social hierarchy. Moreover, we could assume that the development of narrative skills would have been to (1) allow the dominant fathers and chieftons to more easily give complex commands in terms of dense linguistic codes (2) allow people to better remember and recount what their fathers, and their father’s father, had instructed them to do in times of need. This generational chain of command was more important and sacred than anything else. The fathers and chieftons would remember the instructions of their father and chiefton on how and when to plant the crops, how to be brave and fight when the time comes, how to live in the Dorian mode and die a honorable death (so that your fame will live on), etc. At this early point in our social evolution, we can assume that language was represented bilaterally in the brain given its importance for keeping the cultural traditions alive and the social control mechanisms operating smoothly.
Granting all this, we can then hypothesize that a scaffolding effect arose as a result of the linguistic control mechanisms. The scaffold was this: everyday, day after day, our ancestors’ brains would have been directly sculpted by the following habit schema: leader commands, I obey. After so many years, this voice would have sculpted the motor pathways in the brain such that hearing it would always result in obedience, much like modern day hypnosis. Such was life; authoritative to the core. Next, we can suppose that these ingrained obedience patterns might have started “looping” in the brain, like a melody or thought that gets stuck in your head all day. As Jaynes says
Let us consider a man commanded by himself or his chief to set up a fish weir upstream from a campsite. If he is not conscious, and cannot therefore narrative the situation and so hold his analog “I” in a spatialized time with its consequences fully imagined, how does he do it? It is only language, I think, that can keep him at this time-consuming all-afternoon work. A Middle Pleistocene man would forget what he was doing. But lingual man would have language to remind him, either repeated by himself, which would require a type of volition which I do not think he was capable of, or, as seems more likely,by a repeated ‘internal’ verbal hallucination telling him what to do. (p. 134)
It was the unique behavioral opportunies of enduring-attention that provided the selection pressures for the right hemisphere language centers to be readapted for hallucinatory self-regulation. This would explain why schizophrenia has such a strong genetic component and why it remains with us today despite being so dysfunctional in a modern society (answer: because it was once kept people alive to listen to their voices). New evidence is even indicating that auditory hallucinations are more common in “normals” than previously supposed, especially in children (e.g. imaginary companions).
Now, in our imagined society, linguistically-coded verbal commands from fathers to sons dominated the social control mechanisms of behavior regulation. A son grows up everyday listening to his father command him like a puppet. The father himself grew up obeying his father, in addition to the tribal chief (and so on for centuries). The chiefton dies suddenly. We don’t have a concept of death. His body is lying there motionless but he isn’t giving orders anymore. How can we get the chiefton to command us once more? We take his body and clean it, dress it, and prop it up as if he were doing his normal day to day business. We give him food and drink and all his favorite material possessions, trying to appease his spirit so that he will command us again. Wait! A voice belows. The body speaks again! He commands once more! But now it is different. Now he is directly talking to us, more powerful and more authoritative than ever. We cannot refuse his voice; we cannot stop it from compelling us. The voice is heard even when the chieftons body is not around. We cannot close our ears to the thunderous voice. The gods and demigods are born. True ancestor worship begins. Sophisticated burial rituals to induce commands from dead bodies show up in the archeological record. Such work has routinely discovered disembodied heads and scenes of daily life in burial tombs. Why would they mess with the dead bodies of their leaders? To induce auditory hallucinations. Such began religion and the priestclass. Such began schizophrenia and the bilteralization of language on the left, body-controlling side, and the all-knowing language of the gods on the right side, stepping in to command us during times of stress and crutch decision making. The trigger for hallucination is stress but for most moderns, the threshhold is high. For some, however, it is low, far too low (hence schizophrenia).