1. Occipital Lobe Videos: –Brain modules 8,9,10, 11 –Consciousness- Blindsight

2. EYE

3. Rods Cones Rods Cones Receptors: rods and cones 120 million120 million peripheryperiphery sensitivitysensitivity night visionnight vision 8 million8 million centralcentral acuityacuity color visioncolor vision

4. Anatomical Pathway in the Retina

5. Retina

7. Optic Nerve Exits

8. Locating Blindspot

10. Stare at single star for 60-90 sec

12. Color-Deficient Vision People who suffer red-green blindness have trouble perceiving the number within the design

14. axons of retinal ganglion cells 10 6 axons of retinal ganglion cells from each eye converge at optic chiasm and hemidecussate Retinal Ganglion Cells project to: –20% project to the Superior Colliculus (retinotectal/pulvinar pathway) “where it is” –80% of the axons of retinal ganglion cells project to the Lateral Geniculate Nucleus (retinocortical pathway) “what it is” Occipital Lobe

15. The Lateral Geniculate Nucleus of Thalamus

17. Central Visual Pathways: the Visual Cortex Visual Cortex Cortical magnification factor -- foveally weighted: cortical volume is related to retinal area’s spatial resolution -- central 10 degrees of VF around fovea maps to 80% of V1 (primary visual cortex)

18. Receptive Field Properties of Cortical Neurons Based on Hubel and Wiesel Simple Cells orientation selective Response to spots On - Off regions Responds to edges ++++++ ------ ------ Complex Cells movement sensitive can’t predict response from static on off receptive fields

19. Hypercomplex Cells end stopping

21. Form Perception LGN - Parvocellular System V1 (Interblobs) ---> V2 ---> V3 Inferotemporal Cortex (MT) –complex stimuli - grandmother cells –Damage leads to visual agnosia

22. Movement Perception Rods LGN - Magnocellular system V1 ---> V2 ---> V5 V5: middle temporal lobe (MT) –Damage - akinetopsia (unable perceive motion)

23. High-level Visual Processing V1- elementary properties detected (edge,etc) V2 -input from V1 divergence of color, form, location V3 - shape (form) - inferotemporal V4 - color - lingual & fusiform gyri V5 - motion - midtemporal PPC - location - posterior parietal cortex ~

25. Striate Cortex (V1) Many more dimensions in which receptive fields may be described – or “tuning” –Receptive field size –Sensitivity to motion? –Sensitivity to chages in wavelength? –Orientation selectivity? –Occular dominance?

26. Striate Cortex (V1) Projection to V1 from magnocellular portion of V1 –Motion sensitivity (direction and velocity) –Orientation sensitivity –Disparity sensitivity Projection to V1 from parvocellular portion of V1 –Wavelength sensitivity –Orientation sensitivity –Disparity sensitivity

27. V2 – three categories Pale stripes –Wavelength sensitivity –Orientation sensitivity –Disparity sensitivity Thin stripes –Wavelength sensitivity Thick stripes –Motion sensitivity –Orientation sensitivity –Disparity sensitivity

28. V4 – recordings (Color) Stimuli –light patches of different wavelengths Stimuli –light patches of different wavelengths Neural response Neural response

29. MT – recordings (Form) stimuli Neural response Neural response

31. eyetracking