Occipito-Temporal Segment
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Visual pathway segment that conveys signals from primary visual cortex to vision-associated temporal cortex (“ventral stream”)
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Integrates visual information with stored memories for visual recognition of objects, faces, places, colors, and written symbols, including language
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Right hemisphere lesion
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Topographical agnosia
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Loss of recognition of familiar places
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Inability to navigate familiar spaces
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Common acute cause: posterior cerebral artery occlusion
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Common chronic cause: tumor
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Left hemisphere lesion
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Alexia without agraphia
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Inability to read
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Intact writing and spelling
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Common acute cause: posterior cerebral artery occlusion
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Common chronic cause: tumor
Bilateral hemispheric lesions
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Visual agnosia
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Loss of visual recognition of familiar faces (“prosopagnosia”)
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Loss of ability to associate typical colors with familiar objects (“color agnosia”)
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Loss of visual recognition of familiar objects (“visual object agnosia”)
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Common acute cause: posterior cerebral artery occlusion
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Common chronic cause: Alzheimer disease
