Lecture 6 Scenes and Objects

Question 1

What is the inverse projection problem?

Answer 1

task of determining the object responsible for a particular image on the retina (e.g. difficult because any 2D image on retina could be formed by many 3D objects in environment)

Question 2

Why is it so difficult to design a perceiving machine?

Answer 2

• the stimulus on the receptors is ambiguous
• objects can be hidden/blurred
• objects look different from different viewpoints

Question 3

What are occlusions?

Answer 3

objects are partially hidden/obscured

Question 4

What is viewpoint invariance?

Answer 4

allows things to be recognized as equivalent from different perspectives

Question 5

What is structuralism? Who established it? How does it apply to perception?

Answer 5

• school of thought that took a reductionist view of psychological processes (much like a chemist might break down a complex compound into its constituent elements)
• established by Wundt
• views perception as additive combinations of various basic sensations

Question 6

What is the Gestalt approach? How does it apply to perception?

Answer 6

• school of thought that REJECTED STRUCTURALISM
• views perception as a product of the mind grouping patterns according to laws of perceptual organization

Question 7

What is the phi phenomenon? what is another name for it?

Answer 7

• occurs when still images are perceived as being in continuous motion when rapidly alternated across different locations
• aka apparent motion

Question 8

Which phenomenon stimulated the founding of Gestalt psychology?

Answer 8

phi phenomenon

Question 9

what did Gestalt psychologists argue?

Answer 9

the whole is more than the sum of its parts

Question 10

what is the law of illusory contours/law of closure?

Answer 10

easily recognizable objects tend to be seen as complete even if parts may be absent

Question 11

What is the principle of good continuation?

Answer 11

lines tend to be seen as following the smoothest path possible

Question 12

What is the principle of pragnanz? What are two other names for it?

Answer 12

• every stimulus pattern is seen in such a way that the resulting structure is as simple as possible
• principle of good figure or simplicity

Question 13

What is the principle of similarity?

Answer 13

similar things tend to be grouped together

Question 14

What is the principle of proximity?

Answer 14

things that are close together in space tend to be grouped together

Question 15

What is the law of common fate?

Answer 15

objects moving in the same direction tend to be grouped together

Question 16

What is the law of common region?

Answer 16

elements in the same region tend to be grouped together

Question 17

What is the law of uniform connectedness?

Answer 17

connected region of visual properties are perceived as a single unit

Question 18

What is the function of figural cues?

Answer 18

influence perceptual segregation of figure from ground

Question 19

TRUE or FALSE: areas higher in the field of view are more likely to be perceived as a figure (as opposed to the background)

Answer 19

FALSE: areas LOWER in the field of view

Question 20

TRUE or FALSE: convex regions are more likely to be perceived as figure

Answer 20

TRUE

Question 21

Convex regions are more more likely to be perceived as figure. Is this effect stronger or weaker if there is less repetition of form in the the object?

Answer 21

weaker with less repetition

Question 22

What is the difference between objects and scenes?

Answer 22

• a scene is acted within
• an object is acted upon

Question 23

What is masking in terms of assessing perception?

Answer 23

a random pattern that is flashed onscreen immediately after a stimulus presentation, used to prevent persistence of vision that can facilitate further processing after the image has disappeared

Question 24

TRUE or FALSE: the overall gist of a scene is perceived first followed by details

Answer 24

TRUE

Question 25

What are the 5 global image features of scenes that are perceived rapidly and holistically?

Answer 25

1. degree of naturalness
2. degree of openness
3. degree of roughness/smoothness
4. degree of expansion
5. colour

Question 26

What is degree of naturalness?

Answer 26

textured zones and undulating contours (natural) vs straight lines (urban)

Question 27

What is degree of openness?

Answer 27

number/density of objects, whether or not the horizon is visible

Question 28

What is degree of roughness/smoothness?

Answer 28

number/size/complexity of elements

Question 29

What is degree of expansion?

Answer 29

convergence of parallel lines

Question 30

What is the oblique effect a product of?

Answer 30

experience-dependent plasticity

Question 31

What is the light-from-above assumption?

Answer 31

because light comes from above in the natural (and many unnatural) environments, this leads to particular expectations about what information the location of shadows convey about our physical environment

Question 32

What are semantic regularities?

Answer 32

characteristics associated with the functions carried out in different types of scenes

Question 33

What is a scene schema?

Answer 33

knowledge of what a given scene ordinarily contains

Question 34

In Palmer’s 1975 experiment, he briefly presented a context scene, followed by a target picture. What did he find?

Answer 34

• targets congruent with the context were identified 80% of the time
• targets that were incongruent were only identified 40% of the time