roaming the structures
Tim and I are both rather feverishly reading Stanislas Dehaene's new book Reading in the Brain: The Science and Evolution of a Human Invention (actually, Tim, I hope you're not febrile any longer; get better!). Dehaene's book on the neuroscience of reading seems to come along at a consilient moment, when not only neuroscientists, but nearly all of us (all of us reading this blog, anyway) are trying to understand how reading works and how to make it better. Something about Dehaene's picture of the reading brain is central to a theory of consciousness—and forges a connection to The Savage Mind that I find electrifying to contemplate.
Dehaene argues that the advent of writing and reading) is the result of the mind repurposing ancient circuits in the brain to the new work of recognizing graphic symbols and fluently translating them into language. I call it "new" because reading's advent in the human career is quite recent, having emerged a mere five thousand years ago. But reading (and a number of other cultural inventions or magisteria or memes) arise so swiftly precisely because there are robust circuits in the brain of ancient origin, which the human brain—through a property unique in the animal kingdom–is able to recycle with agency and purpose. What we experience as consciousness is bound up in—in fact may be coextensive with—this unique property, Deheane proposes. And he identifies a set of deeply-embedded circuits that seem to give rise to other cultural magisteria: mathematics is founded upon a number of "mathematical objects ... anchored in the brain"; the arts build on circuits that perceive and analyze coherence and wholeness in coordination with more rudimentary circuits sensitive to tone intervals, human emotional states, color, motion; religion springs up to put circuits for causal inference, social intelligence, and even moral sense to more ramified use. And natural science, he argues, springs from and elaborates a deep-seated, neuronally-based drive to classify animals and plants. Starting to sound familiar? But in this short précis I've massively simplified what Dehaene is on about, and have left the impression of a machine-like mind built of used parts—bricolage of a dehumanizing sort. That's not it at all! Because Dehaene also posits a further drive, the one on which in his view both consciousness and culture (linked inextricably here) depend. Something arose in the human brain that roams among these sets of circuits, these structures, and looks for ways to link them together. Headquartered in the frontal lobe, making use of long-axon neuronal connections unique to humans, which knit together far-flung regions of the brain, there is some roving bricoleur who browses the structures looking for places to connect them together. Animals and plants are classified for their uses and their dangers—but they also have relations uncannily like those found by other circuits monitoring social connections. The roving bricoleur (which Dehaene might call consciousness) fancies these comparisons, fawns over them—and produces mythologies out of them. Thus consciousness springs forth from a brain made of meat, shaped by evolution, to wield the endlessly inventive imaginal tools called culture. Thus nature nurtures our nurturing nature.
