One thing that changed pretty dramatically is that the visual cortex, the part of our brain that processes our vision, became dedicated to deciphering text. [...]
As we practice that, more and more neurons get dedicated to reading. Eventually, you no longer have to decipher a particular letter or even a particular word because our brains represent those letters and words — it’s automatic. So we got all the benefits that come with being good readers, whether it’s the value of losing yourself in a novel or the value of gaining complex information from some sophisticated nonfiction book.
But we also lost something. One thing we lost is a lot of our visual acuity in reading nature and reading the world. If you look at older cultures that aren’t text-based, you see incredible abilities to, for instance, navigate by all sorts of natural signs. This acuity in reading the world, which also requires a lot of the visual cortex, we lost some of that simply because we had to reprogram our brain to become good readers.