Question 1

What would happen if you suddenly experienced an involuntary twitch of one of your eye muscles?

Accepted Answer

An involuntary twitch of an eye muscle can cause the world to seem to move because the brain interprets the unexpected movement as motion in the visual field.

Question 2

A neon sign for a bowling alley has flashing lights that make it seem like a ball has gone down the alley and knocked over some pins. What is this illusion of motion called?

Accepted Answer

The illusion of motion created by the flashing lights is called apparent movement. Apparent movement occurs when stationary stimuli in different locations are alternately presented, creating the illusion of movement. In this case, the flashing lights create the impression of a ball rolling down the alley and knocking over pins. Induced movement refers to the perception of movement resulting from a moving background, motion parallax is the phenomenon where objects closer to us appear to move faster than objects farther away when we are in motion, and optic flow is the visual perception of motion created by the changing patterns of visual stimulation as we move through the environment. None of these concepts accurately describe the illusion created by the bowling alley sign.

Question 3

Which of the following is NOT a cue for depth?

Accepted Answer

Induced motion is not a cue for depth perception. It refers to the phenomenon where a stationary object appears to be moving because the surrounding environment is moving. The other three options - binocular disparity, interposition, and motion parallax - are all cues for depth perception.

Question 4

When you watch a movie, the people and objects you see really do seem to move, miraculously enough. In fact, movies actually consist of a sequence of carefully timed still pictures. The phenomenon creating this effect in films is called __________.

Accepted Answer

Apparent movement is the phenomenon that creates the illusion of movement in movies which are actually a sequence of still pictures presented in quick succession. Motion detection, motion parallax, and optic flow are related to motion perception but not specific to the creation of the illusion of movement in movies.

Question 5

Why does the world seem to move when you push on your eyeball through the side of your eyelid?

Accepted Answer

The answer of Why does the world seem to move...

Question 6

What does the canceling-out theory maintain?

Accepted Answer

The canceling-out theory suggests that the brain compensates for voluntary eye movements to maintain a stable perception of the world, preventing the visual scene from appearing to move when the eyes move.

Question 7

A number of intrepid experimenters had themselves injected with drugs that caused a temporary paralysis of the eye muscles. Just as the so-called canceling-out theory would predict, whenever they tried to move their eyes, the world __________.

Accepted Answer

According to the canceling-out theory, when the eye muscles are temporarily paralyzed, any attempt to move the eyes would result in a sensation of the world jumping around. Therefore, option A is the best choice. Option B is incorrect because there is no evidence to suggest that the world moves in a direction opposite to attempted eye movements. Option C is incorrect because the canceling-out theory predicts that there would be a sensation of movement. Option D is incorrect because there is no evidence to suggest that the world would revolve in a counterclockwise fashion.

Question 8

There are a number of depth cues, and we rely on all of them depending on the situation in which we find ourselves as perceivers. Why, according to some theorists, did natural selection favor a system influenced by so many cues, especially given that the information provided by these cues is so often redundant?

Accepted Answer

Different cues become important in different circumstances, so it is advantageous for our perceptual system to be able to adapt to various situations and environments. For example, while binocular disparity is a powerful depth cue, it only works over a limited range of distances and can be affected by certain visual conditions. Other cues like motion parallax or relative size may be more reliable in certain contexts. Therefore, the combination of multiple depth cues allows for more accurate and flexible perception.

Question 9

For reasons of geometry, the projected images of nearby objects move more than those of distant ones. Also, the direction of movement across the retina depends on where we are pointing our eyes. Points closer to us than the target of our gaze appear to be moving in a direction opposite to our own; points farther away appear to be moving in the same direction we are. These patterns of movement provide another distance cue called __________.

Accepted Answer

The patterns of movement described in the paragraph are known as motion parallax, which provides a depth cue based on the relative movement of nearby and distant objects as the observer moves their gaze or themselves. Interposition, synesthesia, and apparent movement are all different perceptual phenomena that do not relate to the specific patterns of movement discussed in the paragraph.

Question 10

Which of the following is a cue for depth?

Accepted Answer

Motion parallax is the cue for depth that involves the apparent movement of objects in the environment at different speeds, depending on their distance from the viewer. Apparent and induced movement are not cues for depth, as they are related to the perception of motion rather than depth perception.

Question 11

Why, as we look from left to right, do objects in front of us not seem to move from right to left?

Accepted Answer

The answer of Why, as we look from left to...

Question 12

Which of the following best describes the phenomenon of motion parallax?

Accepted Answer

Motion parallax is a depth cue in which objects closer to the observer move faster and in the opposite direction to the observer's movement, while objects further away move slower and in the same direction as the observer.

Question 13

A ball is moving on a table. As what does the table serve?

Accepted Answer

The table serves as a frame of reference as it is the stationary background against which the movement of the ball can be observed and measured.

Question 14

All of the following provide cues for the detection of depth except __________.

Accepted Answer

Monocular disparity (the slight differences in the retinal images of the two eyes) provides cues for depth perception when viewing objects at different distances, while texture gradients, linear perspective, and interposition all provide visual cues for depth perception as well.

Question 15

Which of the following statements is false?

Accepted Answer

We perceive motion not only when an image moves across the retina, but also when we move our eyes or head and the image remains stationary on the retina. This is known as motion perception through relative motion. Therefore, statement C is false.

Question 16

Why do we have multiple depth cues available to us?

Accepted Answer

Different cues are effective under different circumstances. Having multiple depth cues available to us allows us to perceive depth accurately in a variety of situations, such as when objects are near or far, stationary or moving, or when we have limited visual information. Each depth cue provides complementary information, which helps us to make more accurate judgments about distance and depth.

Question 17

Animated neon signs seem to move even though there is no actual physical movement. Of what is this illusion an example?

Accepted Answer

Animated neon signs create the illusion of movement through apparent movement, as there is no actual physical movement involved. Induced movement and motion parallax both involve actual physical movement.

Question 18

Which of the following statements is true?

Accepted Answer

Motion parallax is a depth cue that arises from the relative motion of objects as an observer moves, and it can provide depth information even if the observer is moving and the objects are stationary.

Question 19

When does apparent movement occur?

Accepted Answer

Apparent movement occurs when two points of the visual field are stimulated sequentially at certain intervals, creating the illusion of movement between them. This is known as the phi phenomenon and is a type of perceptual illusion.

Question 20

A series of projections of still pictures seems to move. This is the underlying principle for motion pictures. Of what is this an example?

Accepted Answer

The description given in the question fits the concept of apparent movement, which refers to a perception of motion created by a series of sequential stationary stimuli.

Quiz 5: Perception