3. Neuron

4. Neurons
Purkinje cells from cerebellum, dendrites showing calcium concentration

5. Synaptic connection

6. Eye

7. Neural circuitry of the retina

8. Receptors Density - Fovea

9. Photoreceptors

10. Photoreceptors

11. CCD Well
Photon can come from the left or right, depending on the device. It creates an electron-hole pair in the silicon (need about 1.14 ev). The electrons migrates in the N type silicon layer, and creates a voltage difference across the metal-oxide capacitor.

12. Image Capture Huge dynamic range Photons: poisson process.
Noisy at low levels
For low light: large receptors, slow integration
Rods/cones, local adaptation,change of amplitude and time constant, motion deblur

13. Visual receptor types

14. Spectral sensitivity

15. Color Mixing

16. Center-surround Receptive Fields
Modified from PSY280F

17. LGN Layers

18. Physiological Recording

19. Orientation Selectivity

20. V1: Direction selectivity
Modified from PSY280F

21. End-stopped cell

22. Simple Cells

26. Visual Areas

27. Bi-directional Computation
Forward: to layer 4, backward: avoid layer 4.
Rich, and usually reciprocal.
Most models: feedforard, or full connectivity.
Could have important computational implications, but the exact nature of these computations remain for future empirical and computational studies.

31. fMRI Magnet

32. fMRI Activation Slice

33. fMRI Activation