a Occipital
Function Lesion
General Vision Geniculostriate:
- Blindsight
Geniculostriate system:
- Perception of form and colours Visual agnosia’s:
- Depth perception 1. Apperceptive agnosia
- Improved recognition by moving object
Tectopulvinar system: - Simultaneous agnosia
- Tracking, localizing, and following objects with eyes
- In particular, in peripheral visual fields 2. Associative agnosia
- Can copy
Prosopagnosia = inability to recognize faces
Pure alexia = not being able to read
Visuospatial agnosia = no recognition of where you have been before
Defective topographical orientation: right medial occipitotemporal
region
- Cannot make image of environment, trace a map, tell the way
(non-verbal memory)
- Often prosopagnosia, dressing & constructional apraxia
- Normal verbal memory (more LH)
- Severe disturbance in memory (e.g., topographical memory:
don’t recognize you been there already 5 times)
Primary V1 = striate cortex
Secondary V2
Tertiary V3A = form, V3 = dynamic form V3 + V3a no form perception
V4 = colour form
V5 = motion V4 no colour perception