Visual perception (Part 2)

Question 1

What are Gestalts principles

Answer 1

Visual principles that interpret stimuli according to principle that the whole is greater then its sum parts

Question 2

List the 4 different Gestalt principles

Answer 2

1. Figure-ground organisation
2. Closure
3. Similarity
4. Proximity

Question 3

Describe figure-ground organisation (GP)

Answer 3

Organising a scene by differentiating the FIGURE away from the GROUND (eg. contour lines)

Question 4

Describe closure (GP)

Answer 4

Mentally filling any gaps in stimulus to perceive as whole

Question 5

Describe similarity (GP)

Answer 5

Mentally grouping objects with similar qualities (shape, orientation, texture)

Question 6

Describe proximity (GP)

Answer 6

Mentally grouping objects based on position

Question 7

Define depth perception

Answer 7

• Images captures by our retinas
• Ability to interpret the 3d world

Question 8

What are binocular depth cues?

Answer 8

• Depth cues relying from both eyes

Question 9

What is retinal disparity? (BDC)

Answer 9

The cortex uses the degree of differences between the retinal image of left and right eye

Question 10

What is convergence? (BDC)

Answer 10

The cortex uses the tension placed on the orbital muscle to indicate distance form object

Question 11

Define monocular depth cues?

Answer 11

Depth perception form one eye

Question 12

What is accommodation? (MDC)

Answer 12

Eye changes shape to perceive distance

Question 13

State the 5 pictorial depth cues and briefly describe

Answer 13

1. Linear - convergence of parallel lines
2. Relative size - objects cast longer retinal images when they’re closer
3. Interpretation - If an object is obscured the object is closer
4. Texture gradient - finer details indicated distance
5. Height in visual field - objects closer to horizon are further

Question 14

Describe visual consistencies

Answer 14

Principles that help maintain perception

Question 15

What are the 3 visual consistencies?

Answer 15

1. Size - objects are stable despite changes on retinal image
2. Shape - objects are stable despite shape on the retinal image (linear perspective)
3. Brightness - objects are stable despite brightness

Question 16

What is the perceptual set?

Answer 16

seeing situations how we expect to see them

Question 17

What influences perceptual set?

Answer 17

1. Past experiences
2. Context
3. Motivation
4. Emotion

Question 18

Define social influence of visual perception

Answer 18

Interpersonal and environmental factors that effect perception

Question 19

Define ethnocentrism and its issues

Answer 19

• Perceiving your culture/ society as superior
• Can create biased, ethical issues

Question 20

What was Hudson, W (1960) aim?

Answer 20

Investigating pictorial depth perception for 3D and 2D images for African vs Caucasian cultures

Question 21

What was the sampling of Hudson’s 1960s experiment?

Answer 21

6 groups that were schooled (3 x Caucasian, 3x African)
5 groups without schooling ( 1x Caucasian, 4x African)

Question 22

What was Hudson’s 1960 method, results and conclusion?

Answer 22

Method: asked about their perception of a series of 2d and 3d objects
Results: Without schooling were able to perceive 2d, not 3d. there was a higher 3d perception rate in Caucasian sample vs Africans
Conclusion: there ARE cultural differences in perception

Question 23

What were the strengths and weaknesses of Hudson 1960?

Answer 23

Strengths: controlled sample, first research indicating social norms affect perception
weaknesses: generalization for population, ethnocentrism

Question 24

What was Deregowski’s 1972 experiment aim?

Answer 24

Research into if pictorial perception relies on learning. Tested western and African countries. 5 studies were conducted

Question 25

Describe Deregowski's Study 1 (method, results)

Answer 25

method: used Hudson's pictorial depth and people were questioned eg. "which animal is nearer to the elephant?" results: African community had difficulty perceiving pictorial depth

Question 26

How did Deregowski classify his two groups?

Answer 26

2D and 3D perceivers

Question 27

Describe Deregowski's Study 2 (method, results)

Answer 27

method: shown drawing of 2 squares and asked what they saw results: Almost all 3D perceivers built 3D objects, 2D perceivers built 2D

Question 28

Describe Deregowski's Study 3 (method, results)

Answer 28

method: Asked to copy a 2-pronged-trident results: 3D perceivers looked at controlled trident longer, whereas 2D perceivers didn't differ

Question 29

Describe Deregowski's Study 4 (method, results)

Answer 29

method: Participants adjusted light so it appeared the same depth as an object in a picture results: 2D perceivers set light at the same depth (despite what researchers asked) 3D perceivers used depth cues to determine depth

Question 30

Describe Deregowski's Study 5 (method, results)

Answer 30

method: used 'split-type' drawing to represent animals results: 2D perceivers preferred these drawings

Question 31

What were Deregowski's 1972 conclusion, strengths and limitations?

Answer 31

- Non-westerns lacked pictorial depth - Strength: Praised for investigating cultural diversity - Limitations: Ethnocentrism, didn't include texture gradient

Question 32

What was Deregowski, Muldrow and Muldrow 1972's aim?

Answer 32

Presenting drawn familiar objects to remote Ethiopian populations to explore past expenses and perception

Question 33

What was Deregowski, Muldrow and Muldows sample?

Answer 33

41 Ethiopian participants, 33 lowland, 8 highland Equal male and female

Question 34

What was the method of Deregowski, Muldrow and Muldows 1972?

Answer 34

presented 3 pictures in black ink on cloths 1st pic. standing buck 2nd pic. running leopard 3rd pic. hunting scene (similar to Hudons) Then they were asked open ended questions

Question 35

What were Deregowski, Muldrow and Muldows 1972 results and conclusion?

Answer 35

- No major difference between groups - Perception is based on past experiences and familiarity with objects

Question 36

What were Deregowski, Muldrow and Muldows 1972 strengths and weaknesses?

Answer 36

Strengths: investigated remote population, validity was increased due to experimenter's familiarity with the area and people Weaknesses: Violated ethical principles (Ethiopians were distressed), B + W may have changed answers, different answers arose when cloth was moved

Question 37

Define visual illusion

Answer 37

Consistent misinterpretations of external visual stimuli's

Question 38

What was the Muller-lyer illusion?

Answer 38

Two verical lines with arrow head and feather head

Question 39

What is the carpenter world hypothesis?

Answer 39

The lines at the end of stimuli imply depth due to our experiences with right angles through pictorial depth cues of linear perspective and relative size

Question 40

Explain the Ames room illusion

Answer 40

We maintain shape consistency of the room as rectangular at the expense of size consistency of the people in the room

Question 41

Explain the Ponzo illusion

Answer 41

2 diagonal converging lines and is observed further away (height and visual field cue)

Question 42

What are ambiguous figures?

Answer 42

Multiple stable perceptions that manipulate Gestalts principles

Question 43

What are impossible figures?

Answer 43

Stimulus that can not occur in reality by manipulating pictorial depth cues