ANSWER: MT

2. Describe 2 situations in which the retinal image changes but the observer perceives a stationary environment (10 words or less, each).[2 points]

ANSWER: many possible, including eye movements, head/body movements, failures of apparent motion.

3. Describe 2 situations in which the retinal image does not change but the observer perceives object motion (10 words or less, each). [2 points].

ANSWER: many possible, including motion aftereffect, tracking a moving scene; also accepted movement-without-motion.

4. Neurons that respond to the direction of motion of a plaid are known as _____ cells; neurons that respond to the direction of motion of the individual gratings that make up a plaid are called _______ cells. [2 points].

ANSWER: pattern, component.

5. Define crossed and uncrossed disparity, and give the name of the physical division between them. [3 points].

ANSWER: Given a fixated object, objects in crossed disparity are before the fixated object (i.e., person would have to cross their eyes more to fixate an object in crossed disparity); objects in uncrossed disparity are beyond the current fixation point. The horopter is the surface in space that divides crossed and uncrossed disparities, and extends from the fixated object outwards.

[review figure from class notes].