Attention and perception part 2 unit 8

Question 1

What is perceptual organisation?

Answer 1

Perceptual organisation is the process by which elements in the environment are grouped together or separated to form perceptions of objects.

Question 2

What are the two components of perceptual organisation?

Answer 2

Grouping: Combining elements to perceive an object or group of objects.
Segregation: Separating one object or area from another.

Question 3

What is an example of grouping in perceptual organisation?

Answer 3

Perceiving a Dalmatian involves grouping dark areas into the shape of the dog while separating other parts as background.

Question 4

What is an example of segregation in perceptual organisation?

Answer 4

Perceiving individual buildings and the borders between them involves segregation.

Question 5

What is the structuralist view of perception, as proposed by Wilhelm Wundt?

Answer 5

Structuralism sees perception as the sum of individual sensations, like atoms combining to form a molecule.

Question 6

What is the difference between sensations and perceptions in structuralism?

Answer 6

Sensations: Elementary processes from sensory stimulation (e.g., detecting light).
Perceptions: Complex experiences of recognition and awareness (e.g., perceiving an object).

Question 7

Why did Gestalt psychologists reject structuralism?

Answer 7

Gestalt psychologists argued that perception is not just the sum of sensations, as illustrated by phenomena like the stroboscopic effect and illusory contours. stroboscopic effect: how can rapidly
alternating two images produce the illusion of movement if there is nothing actually moving in the
images?

Question 8

What is the stroboscopic effect, and how does it challenge structuralism?

Answer 8

The stroboscopic effect occurs when two lights flash alternately, creating the illusion of movement. This perception of motion cannot arise from individual sensations since no actual movement exists.

Question 9

What conclusion did Gestalt psychologists draw from the stroboscopic effect?

Answer 9

Perception involves more than summing individual sensations.
“The whole is different from the sum of its parts.”

Question 10

What is the illusory contour effect, and how does it challenge structuralism?

Answer 10

The illusory contour effect occurs when objects (e.g., Pac-Man shapes) create the perception of a triangle, even though no physical edges exist. This shows perception is not simply the sum of sensations.

Question 11

What are the principles of perceptual organisation designed to achieve?

Answer 11

These principles help create order and coherence in confusing stimuli by grouping elements together, reducing the cognitive load (similar to chunking in memory).

Question 12

What is the principle of Prägnanz (simplicity)?

Answer 12

It states that we perceive the simplest possible configuration of elements.
Example: The Olympic rings are perceived as five overlapping circles rather than a complex arrangement of shapes.

Question 13

What is the principle of Good Continuation?

Answer 13

Elements following smooth, uninterrupted lines are grouped together.
Example: A wire running in a continuous curve is perceived as a single object rather than being broken into separate segments.

Question 14

What is the principle of Similarity?

Answer 14

Similar elements are grouped together.
Example: In an image, circles of similar color or orientation are grouped as belonging to the same object (e.g., sea and sand in a beach scene).

Question 15

What is the principle of Proximity?

Answer 15

Elements close to each other are perceived as part of the same group.
Example: Dots arranged in clusters are seen as distinct groups based on their spacing.

Question 16

What is the principle of Common Fate?

Answer 16

Objects moving in the same direction are perceived as a group.
Example: A flock of birds flying together is seen as a single entity.

Question 17

What is the principle of Closure?

Answer 17

We perceive incomplete objects as whole by filling in the missing parts.
Example: A broken circle is seen as complete because our mind “closes” the gap.

Question 18

What is the principle of Symmetry?

Answer 18

Symmetrical elements are perceived as unified groups.
Example: A pattern of symmetrical shapes is grouped together more easily than asymmetrical patterns.

Question 19

What is the principle of Common Region?

Answer 19

Elements within the same bounded region are grouped together, even if they are further apart.
Example: Circles within ovals are perceived as groups, even if circles in neighboring ovals are closer.

Question 20

What is the principle of Uniform Connectedness?

Answer 20

Elements that are visually connected (e.g., by a line or common color) are perceived as a single group.
Example: Connected circles are seen as a group, even if they are further apart.

Question 21

What is the figure-ground problem?

Answer 21

It involves determining what part of a scene is the figure (the object) and what is the ground (the background).

Question 22

What is a key property of the figure in figure-ground segregation?

Answer 22

The figure is perceived as having a distinct form or shape and is seen as being in front of the ground.

Question 23

What is border ownership, and how does it relate to the figure?

Answer 23

The contour separating the figure from the ground “belongs” to the figure, not the ground.

The border (or contour) between the figure and ground “belongs” to the figure.
This is why the figure looks like it’s in front, while the ground recedes

Question 24

What happens near the figure-ground border in perception?

Answer 24

The ground near the border appears shapeless and extends behind the figure.

Question 25

How does the reversible face-vase figure illustrate figure-ground perception?

Answer 25

It alternates between perceiving faces as the figure and the vase as the ground, demonstrating the constructive (top-down) nature of perception.

Question 26

What role does top-down processing play in figure-ground perception?

Answer 26

Top-down processing allows the perception to alternate, as opposed to bottom-up processing, which would produce a single, unchanging perception.

Question 27

What did Vecera et al. (2002) find about figure-ground perception in different visual fields?

Answer 27

Subjects are more likely to perceive areas in the lower visual field as the figure than areas in the upper visual field.

Question 28

How does the shape of regions affect figure-ground perception?

Answer 28

Convex (outward-curving) regions are more likely to be perceived as the figure compared to concave (inward-curving) regions.

Question 29

What experiment by Peterson & Salvagio (2008) supported the role of convexity in figure-ground perception?

Answer 29

Subjects judged convex regions as the figure in 89% of trials, suggesting convexity strongly influences figure-ground segregation.

Question 30

What did Gestalt psychologists think about how knowledge affects perception?

Answer 30

They believed that perception mostly relies on inborn principles (like grouping and simplicity) and that what we’ve learned or experienced in the past has only a small effect

Question 31

What example did Wertheimer (1912) use to show innate principles override knowledge?

Answer 31

He showed that when "W" and "M" were configured to violate good continuation, people perceived an unfamiliar object instead of recognizing the letters. This demonstrates that the brain's preference for smooth, continuous lines (good continuation) is stronger than prior knowledge of letters.

Question 32

What did Barense et al. (2012) discover about figure-ground perception?

Answer 32

Healthy controls were more likely to perceive black regions as the figure if the shapes resembled familiar objects. Amnesia patients did not show this effect, suggesting that past experience (memory) aids figure-ground segregation. Healthy people were more likely to see familiar shapes as the figure. Amnesia patients didn’t show this effect, proving that memory and past experiences aid figure-ground segregation.

Question 33

What are scene schemas, and how do they influence perception?

Answer 33

Scene schemas are our knowledge of what objects typically exist in specific contexts (e.g., knives in a kitchen), influencing how we perceive objects in those settings.

Question 34

How did Palmer (1975) demonstrate the influence of scene schemas on perception?

Answer 34

Participants viewed a scene (e.g., a kitchen) and were then shown objects. They identified scene-consistent objects (e.g., a loaf of bread in a kitchen) 80% of the time, but inconsistent objects (e.g., a mailbox) only 40% of the time.

Question 35

How do perceptual illusions demonstrate the constructive nature of perception?

Answer 35

Illusions, such as the illusory contour effect, show that perception involves constructing mental representations that may not directly match sensory input.

Question 36

What do perceptual illusions reveal about perception?

Answer 36

Perceptual illusions show that the information received by sensory receptors is not identical to what we perceive; perception involves constructing mental representations.

Question 37

What is the Müller-Lyer illusion, and what does it demonstrate?

Answer 37

The Müller-Lyer illusion shows that two vertical lines of identical length appear different due to their surrounding fins. This demonstrates that perception can be influenced by context and constructed interpretations.

Question 38

What explanation did Gregory (1966) propose for the Müller-Lyer illusion?

Answer 38

Gregory suggested that the illusion is caused by misapplied size constancy scaling, where the brain interprets the lines as being at different distances, even though they are on a 2D plane.

Question 39

What is size constancy scaling, and why is it important?

Answer 39

Size constancy scaling helps maintain stable perceptions of object size regardless of distance. For example, a person appears the same size whether they are near or far away.

Question 40

How does the Müller-Lyer illusion misapply size constancy scaling?

Answer 40

The inward-facing fins are interpreted as the exterior corner of a room, appearing closer. The outward-facing fins are interpreted as the interior corner, appearing farther away, making the lines seem different in size.

Question 41

What is the Ponzo illusion, and how does it work?

Answer 41

The Ponzo illusion involves converging lines creating depth cues. An object near the top of the lines appears farther away and larger than an identical object near the bottom, due to misapplied size constancy scaling.

Question 42

How does depth perception affect size perception in 2D illusions like the Ponzo illusion?

Answer 42

Depth cues (e.g., converging lines) trick the brain into applying 3D size constancy scaling to a 2D image, making objects at the "farther" end of the lines appear larger.

Question 43

What challenge has been posed to Gregory’s explanation of the Müller-Lyer illusion?

Answer 43

Similar illusions occur even without obvious depth or distance cues, suggesting additional factors beyond size constancy scaling may influence these effects. The illusion might not depend on depth perception but could be due to other factors, such as how the brain processes shapes and visual context