Deck 6: Perceiving Depth

Question 1

Which depth cue would you miss the MOST if you were poked in the eye and had to wear an eye patch for a week?

A) shading
B) binocular disparity
C) motion parallax
D) accommodation

Answer 1

B

Question 2

Which statement BEST describes texture gradient that serves as a cue to depth?

A) Moisture and particles in the air scatter light, which makes objects appear increasingly hazy with distance.
B) The impressions created by stones in a dry riverbed are fairly regular in size and spacing, and the retinal image size of these equal-size features decreases as their distance increases.
C) The top and bottom edges of the train appear to converge and project a smaller retinal image as it recedes from an observer.
D) The objects and surfaces, near the point toward which you are driving, move outward slowly in your retinal image.

Answer 2

B

Question 3

The dynamic monocular depth cues are:

A) familiar size, relative size, and linear perspective.
B) partial occlusion, relative height, and texture gradients.
C) motion parallax, optic flow, and deletion and accretion.
D) atmospheric perspective, shading, and cast shadows.

Answer 3

C

Question 4

_____ is a position-based depth cue. In scenes where one object partially hides another object, this indicates that the former is closer than the latter.

A) Linear perspective
B) Partial occlusion
C) Atmospheric perspective
D) Relative height

Question 5

The types of oculomotor depth cues are:

A) binocular disparity and motion parallax.
B) motion parallax, optic flow, and deletion and accretion.
C) accommodation and optic flow.
D) convergence and accommodation.

Question 6

The oculomotor cues of accommodation and convergence provide information about depth based on information from the muscles that control the _____ and the _____.

A) shape of the lens; retinal image
B) shape of the lens; position of the eyes
C) size of the objects; position of the eyes
D) optic flow; position of the objects in the retinal image

Question 7

The depth cue based on the slightly different retinal images in our two eyes is called:

A) binocular disparity.
B) motion parallax.
C) accommodation.
D) convergence.

Question 8

The size-distance relation states that the father away a(n):

A) object is from an observer, the smaller is its retinal image.
B) object is from an observer, the larger is its retinal image.
C) familiar object is from an observer, the larger is its retinal image.
D) familiar object is from an observer, the more air the light must pass through the retinal image.

Question 9

The oculomotor depth cue that involves adjusting the shape of the lens to focus an image sharply on the retina is called:

A) binocular disparity.
B) convergence.
C) accommodation.
D) optic flow.

Question 10

When the visual angle for a basketball is less than the visual angle for a baseball, then the:

A) basketball must be closer to the observer than the baseball.
B) basketball must be farther away from the observer than the baseball.
C) basketball and the baseball are located at the same distance from the observer.
D) basketball partially occulates a more distant baseball.

Question 11

Douglas looks at a large field of densely packed sunflowers. He notices that the heads of the sunflowers appear to get smaller the farther away they are from his eyes. The depth cue that Douglas perceives is called:

A) the texture gradient.
B) linear perspective.
C) familiar size.
D) relative size.

Question 12

Accommodation provides depth information only for objects up to about _____ m away.

A) 2
B) 10
C) 5
D) 7

Question 13

According to the relative height depth cue:

A) the farther away an object is from an observer, the smaller is its retinal image.
B) the retinal image size of two equal-size features decreases as their distance increases.
C) the lower the base of an object is in the retinal image, the closer the object is to an observer.
D) the higher the base of an object is in the retinal image, the closer the object is to an observer.

Question 14

The position-based depth cues are:

A) binocular disparity and motion parallax.
B) convergence and accommodation.
C) deletion and accretion.
D) partial occlusion and relative height.

Question 15

Martha gazes out the window of a moving train. Billboards, telephone poles, and other objects near the railway track move past Martha very quickly, while objects in the distance move slowly. This illustrates the depth cue of:

A) deletion and accretion.
B) optic flow.
C) cast shadows.
D) motion parallax.

Question 16

In the context of lighting in the retinal image, which statement explains that distant objects appear LESS distinct than nearby objects?

A) The farther away an object is, the less air the light must pass through to reach us, and the more that light can be scattered.
B) When the air is very clear and dry, less air passes through the light to reach us that makes objects appear increasingly hazy with distance.
C) The farther away an object is, the more air the light must pass through to reach us, and the more that light can be scattered.
D) As you move through the environment, more distant objects move more slowly across your retina than nearby objects, making it less distinct.

Question 17

In the context of dynamic cues, as a person moves through the environment, objects farther from the fixation point:

A) appear to move faster than objects nearer the fixation point.
B) appear to move slower than objects nearer the fixation point.
C) appear to move in the same direction as the observer, while objects nearer the fixation point appear to move in the opposite direction.
D) do not appear to move, while objects nearer the observer move in the same direction as the observer.

Question 18

The difference in the speed and direction with which objects appear to move in the retinal image as an observer moves within a scene provide the depth cue of:

A) motion parallax.
B) optic flow.
C) accretion.
D) linear perspective.

Question 19

Larry and Theo are both 6 feet tall. Larry stands at 10 feet from an observer, and Theo stands at 15 feet from the observer. Here, Larry would produce a:

A) smaller visual angle than Theo would produce.
B) larger visual angle than Theo would produce.
C) same-size visual angle as Theo would produce.
D) smaller retinal image than Theo would produce.

Question 20

Cues that provide information about depth on the basis of the position of objects in the retinal image, the size of objects in the retinal image, and the effects of lighting in the retinal image are called _____ depth cues.

A) binocular
B) dynamic monocular
C) static monocular
D) oculomotor

Question 21

In order to switch focus from one object to the other object, an observer in this situation would have to increase the angle of convergence between the eyes. Hence, the disparity of objects closer than the horopter is called _____ disparity.

A) zero
B) stereopsis
C) crossed
D) uncrossed

Question 22

Marr and Poggio (1979) suggested that the visual system determines the correspondences in the two retinal images, and thus it is possible to compute the binocular disparities by making two simple and quite reasonable assumptions about the world when matching features in the left and right retinal images. Here, one of these assumptions states that:

A) if surface variations are fairly regular in size and spacing, the retinal image size of these equal-size features decreases as their distance increases.
B) each feature in one retinal image will match three or more features in the other retinal image.
C) almost every point in the field of view is surrounded by points at different depths.
D) each feature in one retinal image will match only one feature in the other retinal image.

Question 23

Binocular cells are neurons that:

A) respond to parallel lines as they appear to converge and recede in depth.
B) respond best to the stimulation of their receptive fields in both eyes simultaneously.
C) respond to stimulation of one eye only.
D) produce a vivid sense of depth arising from the visual system's processing of the different retinal images in the two eyes.

Question 24

Objects on the horopter produce _____ disparity.

A) zero
B) uncrossed
C) crossed
D) either crossed or uncrossed

Question 25

In the context of perceptual constancy, size constancy is a tendency to:

A) perceive changes in the retinal image size of an object.
B) perceive an object's size as constant, despite changes in the size of the object's retinal image.
C) use variety of cues simultaneously to obtain information about depth.
D) perceive the size of an object in relation to its perceived distance.

Question 26

Objects that are either closer to an observer or farther away from the observer than the horopter will project retinal images that fall:

A) on corresponding points.
B) at zero disparity.
C) at crossed disparity.
D) on noncorresponding points.

Question 27

John leans against a wall and watches a squirrel approach a tree. As the squirrel crosses behind the tree, its body gradually disappears. This illustrates the process of:

A) deletion.
B) accretion.
C) accommodation.
D) crossed disparity.

Question 28

In real-world situations, integrating depth cues provide us with:

A) neural signals that rapidly identify the shape and color of objects rather than locating them.
B) misleading information about objects at higher altitudes as they often lack dynamic cues and binocular disparity.
C) the same or complementary information about the depths of the objects and surfaces in the scene.
D) complex depth cues that are often at conflict with each other.

Question 29

Research findings of random dot stereograms have shown that:

A) object recognition precedes correspondence matching.
B) correspondence matching is not necessary for the perception of binocular disparity.
C) correspondence matching precedes object recognition.
D) object recognition occurs simultaneously with correspondence matching.

Question 30

An anaglyph:

A) requires two slightly different superimposed images.
B) can be viewed without special colored lenses.
C) produces a vivid perception of depth for people viewing an image with only one eye.
D) consists of two depictions of a scene that differ in the same way as an observer's two retinal images.

Question 31

_____ is an imaginary surface defined by the locations in a scene from which objects would project retinal images at corresponding points.

A) The/A horopter
B) Optic flow
C) Stereopsis
D) The/A texture gradient

Question 32

Stereopsis is a depth cue arising from the visual system's processing of the:

A) different retinal images in the two eyes.
B) different retinal images in a single eye at two different times.
C) texture elements that project a retinal image as distance of the object from the observer increases.
D) light that falls on curved surfaces in ways that give rise to shading differences.

Question 33

As the distance between an object and the horopter increases, the binocular disparity for the object _____, regardless of whether disparity is crossed or uncrossed.

A) increases
B) decreases
C) remains unchanged
D) reaches an intermediate point

Question 34

In the context of binocular disparity, a point on the left retina and a point on the right retina are _____ points if they would coincide if the two retinas were superimposed.

A) corresponding
B) noncorresponding
C) horopter
D) crossed disparity

Question 35

Optic flow is a critical cue to depth when a person is driving, though it also operates, of course, when a person moves slowly through a scene. The objects and surfaces near the point toward which the person is heading is called _____, which move(s) outward slowly in the retinal image.

A) motion parallax
B) cast shadows
C) focus of expansion
D) linear perspective

Question 36

A dynamic depth cue-the gradual revealing ("de-occlusion") of an object as it emerges from behind another one-is called:

A) deletion.
B) accretion.
C) accomodation.
D) horopter.

Question 37

Researchers have examined what happens when they manipulate the number of depth cues available and the degree to which those cues conflict. Such experiments have revealed a few basic principles. Identify a basic principle of depth cues.

A) The processing of depth cues requires conscious thought.
B) Multiple depth cues tend to decrease the accuracy of depth perception.
C) Depth perception based on multiple cues is a slow and automatic process.
D) No single depth cue dominates in all situations, and no single cue is necessary in all situations.

Question 38

In the context of binocular disparity, the horopter is an imaginary surface defined by the locations in the scene from which objects would:

A) project retinal images at corresponding points on each retina.
B) project retinal images at noncorresponding points on each retina.
C) produce uncrossed disparity.
D) produce crossed disparity.

Question 39

The process of gradual hiding of an object as it passes behind another one is called:

A) deletion.
B) accretion.
C) accommodation.
D) binocular disparity.

Question 40

As David drives down a long straight road with his eyes focused on the steep cliff straight ahead, the entire landscape at the side of the car whizzes by in a blur and then disappears out the edges of his field of view. Only the point where David is heading remains stationary in his retinal image. This illustrates the depth cue of:

A) stereopsis.
B) deletion and accretion.
C) optic flow.
D) crossed disparity.

Question 41

The next generation of 3-D video will be based on _____ technology, where a viewer will be able to get different views of the scene by moving her head or walking around the display. This will involve dynamic depth cues that result from the viewer's own motion, not just from the motion of objects in the scene.

A) stereoscopic
B) liquid-crystal shutter
C) autostereoscopic
D) holographic

Question 42

Perhaps the most widely accepted explanation of the moon illusion is that, like most other size illusions, it results from a misperception of distance. The actual distance from an observer on the earth's surface to the moon is virtually:

A) greater when the moon is at the horizon,
B) the same when the moon is at the horizon and when it is directly overhead.
C) closer when the moon is at the horizon and when it is directly overhead.
D) the same when the moon is at the zenith position.

Question 43

The tendency to perceive an object's shape as constant, despite changes in the shape of the object's retinal image due to the object's changing orientation, is called:

A) shape constancy.
B) shape-slant invariance.
C) size constancy.
D) binocular disparity.

Question 44

In the context of autostereoscopy, the parallax barrier method works BEST with:

A) the Ames room.
B) handheld video games.
C) corrective lenses for improving vision.
D) forced perspective.

Question 45

In holographic technology, which type of depth cue enables a viewer to get different views of the scene by moving the head or walking around the display?

A) static
B) dynamic
C) binocular
D) monocular

Question 46

In the context of the moon illusion, how does the size-distance relation affect our perception of the moon?

A) It leads us to perceive the moon near the horizon as larger.
B) It leads us to perceive the moon as greater in size well above the horizon than it is near the horizon.
C) It leads us to perceive the moon as being at the height of the clouds, thereby appearing closer when it is near the horizon.
D) It leads us to perceive the moon as actually being farther away from the earth when it is in the zenith position than when it is on the horizon.

Question 47

When viewing a 3-D movie in a theater using 3-D glasses with polarized lenses:

A) everyone in the theater sees a slightly different stereoscopic view.
B) everyone in the theater sees the same stereoscopic view.
C) viewers see either double images or no image at all.
D) viewers get different views of the scene by moving their head or walking around the display.

Question 48

During a recent trip to the airport, you notice a small plane standing at a few hundred yards away, which is lower in your field of view than a jet plane that is standing far in the distance. Explain whether this scenario contradicts the depth cue of relative height in an image.

Question 49

Two cargo boxes fall off a train onto the railway track at a distance of 20 feet apart from one another. These two boxes are viewed together by Jim from a linear perspective. He interprets the tracks as two lines perpendicular to the line of sight and tilted symmetrically inward, rather than as two lines receding into the distance. According to the Ponzo illusion, which statement is MOST likely to be true?

A) The box that is farther away from Jim will appear smaller in size than the box that is closer to him.
B) The box that is closer to Jim will appear smaller in size than the box that is farther away from him.
C) Both the boxes will appear to be of the same size to Jim.
D) The box that is closer to Jim will appear bigger in size than the box that is farther away from him.

Question 50

Which technology has been developed to permit 3-D viewing on television, computer, or mobile phone displays without special glasses?

A) liquid-crystal shutter
B) binocular lenses
C) autostereoscopy
D) holography

Question 51

Emmert's law states that the perceived size of an afterimage:

A) is proportional to the distance of the surface on which it's "projected."
B) remains constant, regardless of the distance of the surface on which it's projected.
C) increases as the distance of the surface on which it's projected decreases.
D) remains constant, despite changes in the size of the object's retinal image due to the object's changing distance.

Question 52

In an fMRI experiment conducted by Murray et al. (2006) where the researchers studied the brain's response to ponzo illusion, it was found that:

A) the objects and surfaces near the point toward which a person heads move outward slowly in the retinal image.
B) when the object is perpendicular to the line of sight, the retinal image has the same trapezoidal shape as the object.
C) there is a larger area of activity in V1 when the participants were fixating at the center of the "large" sphere than when they were fixating at the center of the "small" one.
D) the depth cues of linear perspective and texture gradients lead to the perception of two same-sized spheres.

Question 53

In the Ames room illusion, an observer is required to look through the peephole with just one eye because:

A) that eliminates misperception of distance, which leads to misperception of object size.
B) that eliminates linear perspective and, as the participant moves across the room from left to right, the objects in the room appear to move right to left at different speeds.
C) the objects in the room appear to converge as they recede in depth.
D) that eliminates the binocular depth cue and the trapezoidal shapes all look rectangular.

Question 54

My friend has a picture on the beach where she appears to hold the setting sun in her hands like a ball. This illusion is called the:

A) Ponzo illusion.
B) linear perspective.
C) forced perspective.
D) moon illusion.

Question 55

Shape-slant invariance means that the perceived shape of an object depends on its perceived:

A) distance.
B) depth.
C) size.
D) slant.

Question 56

A man and his son are riding along a tree-lined road. The man stares straight ahead through the windshield as he drives, and his son, sitting in the back seat, looks outside the window. Discuss the depth cues available to each rider.

Question 57

Take a mug and begin to slowly move it toward the tip of your nose. While looking at the mug, continue the movement until the mug actually touches the tip of your nose and your eyes are turned in toward your nose. You begin to feel the tension in the muscles that move your eyes. Explain the depth cue that causes this phenomenon.

Question 58

Which statement explains the principle of size-distance invariance?

A) The perceived size of an afterimage is proportional to the distance of the surface on which it's "projected."
B) The perceived size of an object depends on its perceived distance.
C) The perceived size of an object tends to remain constant, despite changes in the wavelengths and intensity of the light.
D) The depth cues of two objects depend on their perceived distance.

Question 59

The figure given below shows the tabletop illusion. It illustrates that the tabletop on the left is _____ the tabletop on the right.

A) longer and narrower than
B) farther than
C) more distorted than
D) exactly the same shape and size as

Question 60

The Ponzo illusion illustrates the principle of:

A) lighting effects in the retinal image that function as depth cues.
B) size-distance invariance and the powerful influence of linear perspective on size perception.
C) perceived size of an afterimage that is proportional to the distance of the surface on which it is projected.
D) shape-slant invariance, where the perceived shape of an object depends on its perceived slant.

Question 61

At a neighbor's garage sale, you find an old-time stereogram showing a group of people standing at the center of the Eiffel Tower's base, and a zeppelin hovering in the background. How do the relative positions of the main objects change in the left-eye and right-eye pictures, respectively, to achieve the 3-D effect?

Question 62

When we look straight at a rectangular picture frame hanging on a wall, it appears as a rectangle. If we walk off the side and look at the frame from an angle, we still recognize that it is in the shape of a rectangle. Explain the phenomenon that makes the picture frame look rectangular in shape, even when it is viewed from an angle.

Question 63

When you first see the tabletop illusion figure in the text, it is clear that the long table is on the left and the wide table is on the right. However, the two tabletops are identical in shape and size-you can verify this by tracing one of the tabletops and then fitting the tracing over the other tabletop, which it will cover exactly. Illustrate: (A) What does this illusion tell you about the visual system? (B) Why is the illusion sustained, even when you know the tables are the same size?

Question 64

What is the correspondence problem? Explain the different ways in which the visual system has evolved to solve the correspondence problem. How did Béla Julesz's work address this issue and help answer the question of whether object recognition occurs before or after matching corresponding parts of the retinal images?

Question 65

The text describes the next generation of 3-D video based on a technology known as holography. What obstacles would a maker of animated films have to overcome to adopt this technology?

Question 66

On a recent trip to the planet Juno, you encounter creatures with two eyes. Their eyes, however, are arranged vertically on their faces, which resemble a traffic light. Explain the reasons for believing or not believing that the inhabitants on Juno can effectively utilize stereopsis to assess the relative depth of objects on the ground.

Question 67

How would your perception of depth change if your eyes were one foot apart? What depth cues, in particular, would be affected?