Variability in language — from person to person, and for any particular person, from context to context — is all around us. It’s a routine aspect of our mental lives, amazingly complex in its details, but in no way surprising as a phenomenon. Similarly for variability in factual and procedural knowledge: impressively intricate, but familiar.
But now it turns out that more and more of our mental lives is open to variation. As a way into the topic, consider an NPR Radiolab segment from 2024 that came by me on KQED-FM a while back, on the phenomenon of aphantasia.

