"I think the evidence is pretty strong that this flexibility in the space of priors over language only lasts a for small precious window until we become adults,

"I think the evidence is pretty strong that this flexibility in the space of priors over language only lasts a for small precious window until we become adults, and then we're all stuck with lame accents." I think this is true for most people, not everyone. If this is true for most people, we can locate these differences by comparing autistic people who quickly acquire languages as adults with normal people. It's interesting that autistic people skilled with language often don't have noticeable accents in that language, even with a language they learn in adulthood. This flexibility in the space of languages involves a honing of perception. As you learn your first language, you become better at perceiving the sounds of that language, but your ability to perceive the sounds of another language go down. For example, a person who speaks exclusively english speaker cannot discern between sounds that would have different meanings that a chinese speaker would easily hear. (Deferentially), I think you are wrong about where the hardwiring occurs. I think the hardwiring that limits most peoples ability to learn language arises is perception, not the space of priors. I believe if you could change the hardwiring that occurs in making sensory discriminations relevant to the language, the "space of priors" would still show the ability to learn language. It's true that there is a precious window for most people to learn languages, but that's because the perceptual paths get hardwired, not the memory and processing that make up what we seem to be calling the "space of priors" But, that's not the scale of time dependance I was thinking. Even if the scale of time dependence was 5 seconds, and the new data was just seeing it was raining out, the way your brain understands the concept of rain involves accessing memories it destroys and recreates as part of recognizing "rain", as well as the particulars of your emotional state and what's going into your sense of smell, so much that the set of priors 5 seconds before would be different then the ones now, even if you took out the information about it raining.