Chapter 6

Question 1

What are oculomotor cues?

Answer 1

Cues based on the movement and focus of the eyes (within ~2m).

Question 2

What are monocular cues?

Answer 2

Depth cues that can be perceived with one eye.

Question 3

What are binocular cues?

Answer 3

Depth cues that require both eyes and use disparities between them.

Question 4

What are metrical cues?

Answer 4

Provide quantitative information about distance.

Question 5

What are non-metrical cues?

Answer 5

Provide only relative depth or depth order information.

Question 6

What is accommodation?

Answer 6

The contraction of ciliary muscles to focus on objects at different distances.

Question 7

What is vergence?

Answer 7

The positioning of the eyes to focus on an object.

Question 8

What is convergence?

Answer 8

Eyes turn inward to look at a near object.

Question 9

What is divergence?

Answer 9

Eyes turn outward to look at a distant object.

Question 10

What are static monocular cues?

Answer 10

Cues available from a single static image (e.g., occlusion, size, texture).

Question 11

What are dynamic monocular cues?

Answer 11

Cues that depend on motion (e.g., motion parallax, optic flow).

Question 12

What is partial occlusion?

Answer 12

If one object blocks another, it must be in front; provides relative depth info.

Question 13

What is relative height?

Answer 13

Objects closer to eye level appear further away; provides relative depth info.

Question 14

What is familiar size?

Answer 14

Knowing an object’s true size allows estimation of absolute distance.

Question 15

What is relative size?

Answer 15

Smaller identical objects are perceived as farther away; relative metrical cue.

Question 16

What is texture gradient?

Answer 16

Repeating patterns provide cues about distance as texture becomes finer with depth.

Question 17

What is linear perspective?

Answer 17

Parallel lines appear to converge with increasing distance.

Question 18

What is atmospheric perspective?

Answer 18

Distant objects appear bluer and less distinct due to light scattering.

Question 19

What is shading?

Answer 19

Light and shadow variations on surfaces create a sense of depth.

Question 20

What is motion parallax?

Answer 20

As we move, nearer objects move faster across the visual field than distant ones.

Question 21

What is optic flow?

Answer 21

When moving forward, objects appear to expand from a central point of motion.

Question 22

What are deletion and accretion?

Answer 22

Changes in occlusion over time as objects move in and out of view.

Question 23

What is stereopsis?

Answer 23

Depth perception arising from binocular disparity between the eyes.

Question 24

What is the horopter?

Answer 24

Imaginary surface where objects fall on corresponding retinal points; zero disparity.

Question 25

What is crossed disparity?

Answer 25

For objects closer than the horopter (image shifts left in right eye, right in left eye).

Question 26

What is uncrossed disparity?

Answer 26

For objects farther than the horopter (image shifts right in right eye, left in left eye).

Question 27

How does disparity magnitude relate to distance?

Answer 27

The greater the distance from the horopter, the larger the disparity.

Question 28

What are cyclopean stimuli?

Answer 28

Stimuli defined entirely by binocular disparity (e.g., random dot stereograms).

Question 29

What are random dot stereograms?

Answer 29

Cyclopean images where disparity defines shape perception.

Question 30

What are 'Magic Eye' pictures?

Answer 30

Cyclopean images relying on free fusion (deliberate eye uncrossing/crossing).

Question 31

What is the correspondence problem?

Answer 31

Determining which parts of each eye’s image correspond to each other.

Question 32

Where does binocular processing occur?

Answer 32

In V1, where binocular neurons compare inputs before object recognition.

Question 33

How does the brain combine depth cues?

Answer 33

By integrating available cues and using prior knowledge for the most likely interpretation.

Question 34

What is the Bayesian approach to depth perception?

Answer 34

Uses probability: P(Scene|Input) = P(Scene) * P(Input|Scene).

Question 35

How can depth cues be misleading?

Answer 35

Depth perception can alter perceived size (size–distance scaling illusions).