Reading · The Changing Brain

If you remember, we started this series with Julian Jaynes’s idea that writing led to suppression of the non-dominant, hallucinating hemisphere and the loss of the gods. Later, we looked at the memories of medieval scholars. The scarcity of books, the inconvenience of scrolls, and scripta continua made memorizing an entire text the only practical way to access what had been written, and scholars regularly carried the contents of hundreds of books in their heads. Printing rendered memorization unnecessary, and the skill was lost in a generation. Reading, writing, and memorizing are learned skills—the brain has to be trained to do them, and that training changes the brain. To know whether generative artificial intelligence might cause similar changes, we need to look at how brains work.

Learned skills come in three general categories. Procedural memory—what we usually call muscle memory like riding a bicycle, typing, or playing scales—is automatic and not readily reduced to computer code. Episodic memory involves experiences from one’s past. It is difficult to code directly, but it can be captured and filed as audio and video recordings. For 13^th century scholars and for those of us in the age of AI, semantic memory is the interesting kind. It involves things like meanings, definitions, and concepts that are not specific to a single time or place. Semantic memory is uniquely adaptable to being stored in a database and to being coded. It deals with facts unlike episodic memory which brings back situations and procedural memory which lets us perform learned actions without thinking.

If you recall, memory is stored in two ways. In the short term, the strength of synapses changes so neurons connect to one another either more or less readily. In the long term altogether new synapses and even new neurons form.[1] In addition, different kinds of memories are stored in different places. When an external stimulus (somesthetic, auditory, visual) comes into the brain it is relayed to the cortical area responsible for processing that sort of stimulus (parietal lobe, temporal lobe, occipital lobe). Implicit memories—automatic skills and habits—are forwarded for storage in the cerebellum, the deep brain striatum, and the amygdala in the medial hippocampus to be recalled as needed. Once relayed, the memories can held briefly or converted and saved. In each case, training changes brain structure.

Now let’s go back to history. Before writing, the elements of culture were preserved by bards and poets who learned society’s stories. Rhythm, rhyme, and formula were learned and passed from generation to generation as poetry and performance saved cultural information. Writing was a new, more efficient way to preserve that information and it freed Greek brains to write plays and to speculate about how the body, the body politic, and the world worked. Homer gave way to Aristotle.

Much the same happened in the Middle Ages. Before printing, creativity had come to be viewed with more than a little skepticism. Anything beyond what was passed down from the Greeks and Romans or the Church fathers and the Bible was frivolous. Intelligence was measured by how much ancient writing one had stored in his or her (mostly his) memory. The more you could recite, the smarter you were. Moveable type changed all that. In a generation or two, memory was externalized—it was outsourced to printed books. How much information you knew quickly became less important than how much you knew about where to find it. As fast as memory declined in importance the skills associated with memorization atrophied, and brain space was freed up to discover calculus, anatomy, and astronomy.

That brings us to the present day, but first a quick recap: information processing as speech caused anatomic changes in the brain that were passed down genetically, but that process took hundreds of thousands of years. On a much shorter time course—that of a single human life—training changes brain circuitry. Learning changes not only how neurons connect to one another but also how many connections there are. Parts of the brain with a host of new connections become more important and occupy more of our conscious attention. Skills change, and sometimes those that are less important drift into the background or are lost altogether. That brings us to AI.

Computers are staggeringly adept at the same skills needed for semantic memory. IBM’s Watson can process 500 gigabytes of information—roughly a million books—a second. We can never hope to match the information and its retrieval or the ability to find relationships between bits of information that Chat GPT will have. It is plausibly predicted that general AI will have an operating system equivalent to that of the human brain by 2050. Much of what we have prioritized our left brains to do will likely be outsourced to computers.

So what do we do about that? We could try to eliminate AI, but even if we wanted to that time has passed. Besides, censorship has never worked well; witness printing, the Church, and the Inquisition. We could try to limit the use of AI, but that just puts us at the mercy of those who choose not to impose limits. The best we can do is to keep the machines’ answers honest and try to understand what they are doing.

The third alternative, and the one we most likely will have to take, is to partner with AI, but that will involve rearranging our brains. What might that look like? Ulrich Kraft said, “The left hemisphere is responsible for convergent thinking and the right hemisphere for divergent thinking. The left side examines details and processes them logically and analytically but lacks a sense of overriding, abstract connections. The right side is more imaginative and intuitive and tends to work holistically, integrating pieces of an information puzzle into a whole.”

How about a metaphor or two?

The left brain sees trees. The right brain sees the forest.

The left brain is an accountant. The right brain is an artist.

The left brain is a navigator. The right brain is an explorer.

The left brain plays chess. The right brain dances.

The left brain is a journalist. The right brain is a novelist.

Full disclosure—I am terrible at metaphors. Those were all from Chat GPT.

As we have seen, written language has made our left brains dominant and suppressed the other side. If we outsource what the left brain does, we might free conscious space for other uses much like writing let Aristotle imagine biology and printing let Newton dream up gravity.

There are clues that might actually happen. People with left brain damage from fronto-temporal dementia will occasionally develop musical and artistic ability they never had before becoming ill. Allen Snyder used transcranial magnetic stimulation to temporarily impair left brain function and the experimental subjects suddenly had new artistic skills. It is even possible that not needing to learn the order of the presidents or capitals of states will contribute to the visual-spatial skills of video game players.

Writing made the left brain dominant, but writing is a learned skill. Maybe a different kind of learning will bring back the right side. Printing made memory less important, and time spent with that skill went elsewhere to mankind’s great benefit. Speech was associated with major changes in brain anatomy. Although those changes took a very long time, unlike learned skills they were heritable. Maybe if we last long enough, AI will turn us into a different sort of thinking organism.

Of course, that is all pure speculation.

AND WHAT WE LOSE

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