1. Psychology 100:12 Chapter 5 Sensation & Perception Part III

2. Outline Basic Sensory Processes Vision Transduction Colour Receptive fields Feature detectors Study Question: Compare and contrast the trichromatic theory of colour vision with the opponent process theory of colour. Relate these theories to the Law of Complimentary and the Three Primaries Law.

3. Vision: The Physical Stimulus Vision

4. Sensation The Eye Vision

5. Sensation Vision: The Retina Vision

6. Sensation Rod and cone vision –Cones >Specialized for colour and acuity >concentrated in fovea –Rods >Specialized for sensitivity in dim light >concentrated in periphery –Both contain a photochemical that reacts to light (in the rods: rhodopsin) –Two reasons why rods are more sensitive to light 1.Rhodopsin is more sensitive to light 2.Density of cones in the fovea Vision

7. Sensation Colour Vision –The colour of objects is determined by pigments –Subtractive colour mixing >Colour perception is created by absorption of wavelengths of light Vision

8. Additive Colour Mixing –When coloured lights are mixed, two laws apply: >Three Primaries Law >Law of Complimentarity

9. Vision

10. Two Theories of colour vision –Trichromatic theory > -> the three types of receptors are sufficient for colour perception

11. Opponent Process theory –Trichromatic theory does not account for complimentary colours. –Colour vision is mediated by cells that can be excited or inhibited –Blue- Yellow, Red - Green, & brightness Vision

13. Contrast Coding of Contrast and Contour –Three examples of exaggerated contrast

14. Contrast Coding of Contrast and Contour –Three examples of exaggerated contrast

15. Contrast Coding of Contrast and Contour –Three examples of exaggerated contrast

16. Contrast heightening Contrast Coding of Contrast and Contour –Receptive fields and on-off areas

17. Hermann - Hering grid Coding of Contrast and Contour Contrast

18. Receptive fields and the Hermann-Hering illusion Coding of Contrast and Contour Contrast

19. Feature detectors –Hubel and Weisel > Simple cells - edge detectors > Complex cells - edges at particular angles > Hypercomplex cells - angles and length – Higher level feature detectors: Motion detectors Vision

20. Feature detectors More From Ramachandrin Vision