Where do conventions come from? Constraints or plasticity of the human brain: Follow-up note

This is a follow-up note to an old article of mine, published in Style (Tsur "Poetic Conventions"). That article asks the question where do poetic conventions come from, arguing against a "migration" or "influence-hunting" approach. My answer is based on a conception of cognitive constraints; ultimately, on the natural constraints of the human brain. In that paper I quote experimental evidence regarding the general principles of repeated social transmission by which cultural programs assume good fit to the constraints of the human cognitive system, but not specifically to the constraints of the brain. The present paper fills in that gap by extensively quoting Dehaene's paper in neuroscience, that a well-defined area in the brain constrains the graphic primitives of the characters in all known writing systems. "Even in the macaque monkey, the inferotemporal visual cortex already contains neurons sensitive to letter-like combinations of lines such as T, L, X, and *."