ANAT 321 Lecture Notes - Lecture 21: Visual Hierarchy, Prosopagnosia, Birdwatching
1 Nov 2016
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Document Summary
If you stain the primary visual cortex with a metabolic stain, you can map out the blobs: you cannot see blobs in. See instead stripes: thick, thin, and interstripes. The thick stripes receive output from the primary visual cortex that eventually form the dorsal stream. Thin stripes and interstripes contribute to the ventral stream. The threshold of that detection is around 10% (of dots moving in the same direction: they perform better when the speeds are slower, with the lesion, they cannot detect motion anymore. The results are similar with humans - cannot detect motion: people who have lesions to the dorsal stream have remarkable motion-specific deficits, they do not see motion continuously, more like in a stop-motion, a set of discrete snapshots. Lesions in area mst monkeys and humans produce deficits in smooth pursuits movements. This area allows the eyes to follow smooth movement: to follow a moving object, smooth pursuit movements - entirely dependent on a moving object.
