Review of Pathway Underlying Vision

1. Partial decussation allows binoc interaction @ VC
2. Visual Cortex = first level of convergence of signals from the two eyes
3. Retina & LGN cells have circular receptive fields but cortex has rectangular visual fields which respond best to line stimuli at a particular meridian
4. Cells in the cortex are orientated in a columnar manner
5. Majority of cortical cells are binocularly driven but not equally influenced by each eye
6. Groups one and seven are monocular
7. Group four is equally responsive
8. When identical stimuli are presented to both eyes the firing rates of most cortical binocular cells exceed the sum of the individual firing rates for each eye. These cells may provide the basis for fusion.
9. There are binocular disparity cells. The optimal stimuli for a few of the binocular cells are not located at corresponding regions of the visual field of the two eyes - they are shifted horizontally. These cells may provide the basis for stereopsis.