1. Visual Cortex
Vision Science Lectures in Ophthalmology
Curtis Baker

2. receptive fields of retinal ganglion cells
KSJ, Fig 26-7

3. retina-LGN-cortex
KSJ, Fig 27-4

4. V1 neurons: orientation selectivity
KSJ,
Fig 27-11

5. V1 neurons: direction selectivity

6. neurons as stimulus filters
simple cell receptive field
wrong spatial frequency + - + -
optimal grating
wrong orientation + - + -

7. ocular dominance columns
KSJ, Fig 27-16

8. Population responses: optical imaging
CCD Camera
Stimulus Generator
Illuminator
Real-time Video Processor
Data Collection and Analysis
(courtesy of Chang’an Zhan)

9. orientation columns
KSJ, Fig 27-14

10. cytochrome oxidase blobs
KSJ, Fig 27-15
input from LGN koniocellular layers
in centers of ocular dominance columns
receptive fields: non-oriented, colour-opponent

11. retinotopic map in V1
KSJ, Fig 27-9

12. retinotopic maps from fMRI
Sereno et al, 1995

13. field sign maps
Sereno et al, 1995

14. extrastriate visual areas
larger receptive fields, less retinotopy
functional specializations
single units: Zeki, V4 vs MT/V5
brain imaging: stimuli that selectively activate
(e.g., motion/flicker -> MT/V5)
KSJ, Fig 25-9

15. dorsal & ventral streams: many extrastriate areas
KSJ, Fig 28-2

16. dorsal and ventral streams: neurophysiology
KSJ, Fig 25-12

17. effects of damage striate cortex (V1) -> blindness
V2 -> "quadrant" blindness
other extrastrate areas -> selective losses, e.g.:
MT / V5 -> motion-blindness
FFA (fusiform face area) -> prosopagnosia
fusiform cortex ("colour area" ?) -> achromatopsia