Goldstein

Sensation & Perception, 8e

Chapter 3: An Introduction to Vision

Learning Objectives

At the end of Chapter 3, the student should be able to:

1. Discuss how the electromagnetic spectrum is related to vision.

2. Describe how the cornea and lens focus the image on the retina.

3. Discuss why the near point is used as a measure of presbyopia.

4. State the difference between myopia and hyperopia, and treatments for both.

5. Describe the role of visual pigments in transduction.

6. Discuss the procedure and results of Hecht et al.’s (1942) experiment on isomerization.

7. Define the enzyme cascade.

8. Discuss the differences between the distribution of the rods and the cones.

9. Explain why the “blind spot” exists, and why we are not usually aware of it.

10. Name two visual conditions that differentially affect the rods and the cones.

11. Describe the method for measuring dark adaptation, and the overall results.

12. Describe the method for isolating the rod and cone components of the dark adaptation curve, and the results for each.

13. Explain how visual pigment regeneration is related to dark adaptation.

14. Describe the difference in spectral sensitivity curves between rods and cones.

15. Define the Purkinje shift, and discuss how spectral sensitivity curves explain this phenomenon.

16. Describe what convergence is, and the difference in convergence between the rods and cones.

17. Explain why convergence results in greater sensitivity.

18. Define visual acuity.

19. Identify the difference in acuity between foveal and peripheral vision.

20. Explain why the lack of cone convergence results in greater acuity.

21. Define lateral inhibition.

22. Discuss the Hartline et al. research that demonstrated lateral inhibition.

23. Experience three perceptual phenomena that can be explained by lateral inhibition (Hermann Grid, Mach Bands, and simultaneous contrast). The student should then be able to describe each and discuss the explanation of each.

24. Experience a phenomenon that is not explained by lateral inhibition (White’s illusion). The student should then be able to describe the phenomenon, discuss why lateral inhibition does not explain the effect, and explain a theory that does explain the effect.

25. Discuss what is meant by the phrase “Perception is indirect” for different modalities.