Occipito-Temporal Segment

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

    Vision Pathways

    Overview Videos All Segments Considered Optical Segment Prechiasmal Segment Chiasmal Segment Retrochiasmal Segment Occipito-Parietal Segment Occipito-Temporal Segment