1. Duplex retina
First instance of vision as ‘multiple specialized systems that operate in parallel’
Partitions for sensitivity (rods) and resolution (cones).
Because of this division of labour (also called partitioning or parallel processing) we say we have a duplex retina

10. Center surround receptive field
Bipolar and ganglion cells generate a retinotopic map of differences in illumination. They have on-centers/off- surrounds or off-centers/on-surrounds. They ignore absolute light levels.
This is true both for cone pathways and rod pathways.

13. Magnocellular and parvocellular pathways
Larger ganglion cells with more inputs project to magnocellular pathway (large cells in the lateral geniculate nucleus). Responses are more transient.
Smaller ganglion cells with few inputs project to parvocellular pathway (small cells in the lateral geniculate nucleus). Responses are more sustained.

15. Magnocellular and parvocellular functions
Magnocellular pathway is specialized for motion detection and is more sensitive since it sums over a larger area. Good temporal, poor spatial resolution.
Parvocellular pathway is specialized for detail analysis, acuity, form, and color. Good spatial, poor temporal resolution.

17. Geniculostriate pathway
Optic nerve projects to lateral geniculate nucleus. Other parallel pathways go to superior colliculus, pulvinar and hypothalamus.
Six layers in lateral geniculate. Two magnocellular layers and four parvocellular layers.
Ipsilateral eye goes to layers 2, 3, 5. Contralateral eye goes to layers 1, 4, 6.

19. Ipsilateral eye goes to layers 2, 3, 5
Ipsilateral eye goes to layers 2, 3, 5. Contralateral eye goes to layers 1, 4, 6.

22. Where is the damage?

24. Two important ideas 1. Receptive fields that detect differences
2. Magnocellular and parvocellular pathways