Our authors propose to explain this with a model in which a stimulus is encoded in the brain as both a fine-grained representation of what was actually seen (this-and-such color perception, with some noise/measurement-error), and as a category ("green"). Then reconstruction of the stimulus from the both the fine-grained representation and the category, will be biased towards the center of the category, with more bias when the fine-grained representation is more uncertain (as in the delayed condition).
Our authors propose to explain this with a model in which a stimulus is encoded in the brain as both a fine-grained representation of what was actually seen (this-and-such color perception, with some noise/measurement-error), and as a category ("green"). Then reconstruction of the stimulus from the both the fine-grained representation and the category, will be biased towards the center of the category, with more bias when the fine-grained representation is more uncertain (as in the delayed condition).