Right now I'm reading Oliver Sacks' The Man Who Mistook His Wife for a Hat for Neuro 524. It's a series of case accounts of patients with neurological disorders, including one case of a man who could see features of objects but not identify the objects themselves, thus on one occasion mistaking his wife for a hat. One interesting feature of the book is the way Sacks puts manages to relate philosophical ideas to his cases in novel ways. One patient had totally lost the ability to form new memories, preventing him from doing even simple tasks taking any amount of time. Sacks described him as fitting Hume's model of the human mind: a series of impressions utterly disconnected from eachother.
This made me wonder if the man who mistook his wife for a hat too was really having memory problems. As I've previously noted, our peripheral vision is surprisingly limited. Might the man have lacked sufficient vision-memory, or a certain type of vision-memory, necessary to reconstruct it as his eyes scanned across it, thus only able to comprehend the small part of an object able to be in the center of his visual field at any one time?