the primary visual cortex constructs an internal model that allows it to anticipate the data streaming up from the retina (see the appendix for an anatomical guide). The cortex sends its predictions to the thalamus, which reports on the difference between what comes in through the eyes and what was already anticipated. The thalamus sends back to the cortex only that difference information—that is, the bit that wasn’t predicted away. This unpredicted information adjusts the internal model so there will be less of a mismatch in the future.
