I have pretty high confidence that “visual imagination” is accessing the same world-model database and machinery as “parsing a visual scene” (and likewise “imagining a sound” vs “parsing a sound”, etc.)
Update: Oops! I just learned that what I said there is kinda wrong.
What I should have said was: the machinery / database used for “visual imagination” is a subset of the machinery / database used for “parsing a visual scene”.
…But it’s a strict subset. Low-level visual processing is all about taking the massive flood of incoming retinal data and distilling it into a more manageable subspace of patterns, and that low-level machinery is not useful for visual imagination. See: visual mental imagery engages the left fusiform gyrus, but not the [occipital lobe].
(To be clear, the occipital lobe is not involved at inference time. The occipital lobe is obviously involved when the left fusiform gyrus is first learning its vocabulary of visual patterns.)
I don’t think that affects anything else in the conversation, just wanted to set the record straight. :)
Update: Oops! I just learned that what I said there is kinda wrong.
What I should have said was: the machinery / database used for “visual imagination” is a subset of the machinery / database used for “parsing a visual scene”.
…But it’s a strict subset. Low-level visual processing is all about taking the massive flood of incoming retinal data and distilling it into a more manageable subspace of patterns, and that low-level machinery is not useful for visual imagination. See: visual mental imagery engages the left fusiform gyrus, but not the [occipital lobe].
(To be clear, the occipital lobe is not involved at inference time. The occipital lobe is obviously involved when the left fusiform gyrus is first learning its vocabulary of visual patterns.)
I don’t think that affects anything else in the conversation, just wanted to set the record straight. :)