Learning Objectives

1.) Discuss the role of the ganglion cells in visual processing. Describe in detail how these cells respond when activated by light and explain the resulting neural processes.

2.) Describe in detail what is meant by a ganglion cells receptive field, include an explanation of center surround on-off response regions and lateral inhibition.

3.) Discuss the role of the horizontal, bipolar, and amacrine cells including their location in the retina and their relationship with the photoreceptor cells.

4.) Compare and contrast the three types of ganglion cells (M, P, and K) including their individual characteristics and specialized roles in visual processing.

5.) Distinguish between the terms "brightness" and "lightness".

6.) Explain the theory of center/surround antagonism using as support the Hermann grid and Mach band illusions.

7.) Summarize the evidence implying that brightness contrast and Mach bands has to involve more than lateral inhibition.

8.) Discuss lightness constancy and contrast. Include in your discussion their effect on visual perception and any consequences they might have - positive or negative.

9.) Discuss the relationship between retinal eccentricity and convergence. Explain the aspects of neural convergence, the relevance of receptive field size, and the distinction between sensitivity and resolution.

10.) Discuss the importance of stimulus duration and size with respect to the sensitivity of the eye. Distinguish between Bloch's Law and Ricco's Law and explain the direct implication of both laws to our understanding of the visual system.

11.) What is meant by visual acuity and specifically 20/20 vision? Specify those factors known to influence visual acuity.

12.) Distinguish between scotopic and photopic vision and their relationship to visual sensitivity. Include in your discussion the Purkinje shift.

13.) Explain the mechanism behind dark adaptation. Discuss the role of the rods and cones as well as the effect on the scotopic and photopic systems.