Week 11 (Perception)

Question 1

Sensation vs Perception

Answer 1

Sensation: The ability of the sense organs to detect various forms of energy (light and sound waves)
Perception: The analysis of this sensory information to describe the surrounding environment.

Question 2

What is the top-down approach to perception?

Answer 2

-Emphasise existing knowledge and prior expectations (but not exclusively)

Question 3

What is the bottom-up approach to perception?

Answer 3

-Emphasise the primacy of sensation and environment (to varying degrees)

Question 4

What are the basics of the Ecological approach to perception?

Answer 4

-We should focus on real environments and not 2D stimuli
-All necessary info can be ‘picked up’ from the environment

Question 5

What is the ambient optic array?

Answer 5

-The structure/pattern of light
-Light reflects of surface before reaching the eyes
-Information in optic array changes as you move through it.

Question 6

What are invariants?

Answer 6

Properties of an environment that remain static, or (do not vary) as we move through them. E.g., size constancy

Question 7

What did Gibson (1979) suggest about affordances?

Answer 7

That the patterns of light directly ‘afforded’ the use of objects, perception and action are directly linked.
-I.e, a banana ‘affords’ being eaten
-Theory is controversial as it discounts any knowledge or expectations on the part of the individual.

Question 8

What are the two key principles of Constructivism?

Answer 8

1. Information from sensations are incomplete and imperfect.
2. Therefore, perceptual knowledge needed to unconsciously ‘construct’ our perceptions.

Question 9

What is the hollow face illusion?

Answer 9

Despite knowing what we are seeing is hollow (concave)
We perceive it as projecting towards us (convex) and this is how faces are experienced

Question 10

What year was the Kanisza illusion discovered?

Answer 10

1955
-Hypothesising a nearer surface which occludes objects below
-Accounts for surprising gaps and produces the illusory objects in the middle.
-The size, shape and colour of the occluding surface are determined by context.

Question 11

What are two examples of evidence for top-down processing?

Answer 11

-The configurable superiority effect
-The object superiority effect

Question 12

What is the object superiority effect

Answer 12

Counterintuitively, perceptual properties of a display are picked up faster if part of an object.

Argues for high order object knowledge

Question 13

What is the configural superiority effect?

Answer 13

Similar to object superiority effect, however demonstrations are more concerned with context aiding perception, regardless of whether it forms a plausible object.

Argues that being “object-like” is less important than the context providing distinctive information.

Question 14

What does Gestalt mean

Answer 14

Humans perceive things as ‘wholes’ rather than individual parts.

“the whole is different than the sum of it’s parts”

Question 15

What are the five Gestalt laws of organisation?

Answer 15

1. Proximity
2. Similarity
3. Closure
4. Good continuation
5. Common fate

Question 16

Gestalt’s proximity

Answer 16

Elements that are close together are seen to group together

Question 17

Gestalt’s similarity

Answer 17

Elements that are similar are perceived as grouping together.

Question 18

Gestalt’s Closure

Answer 18

We ‘fill in’ gaps to see whole or complete objects

Question 19

Gestalt’s Good continuation

Answer 19

No perceived break in continuation across intersections

Question 20

Gestalt’s common fate

Answer 20

Objects moving in the same direction and speed are perceived as a group.

Question 21

Limitations of Gestalt theories

Answer 21

-Too simplistic
-Largely descriptive, lacks predictive power
-Captures 2d displays but not easy to apply to 3d.

Question 22

What are the constraints (phenomena they must be able to account for) of object recognition.

Answer 22

1. Recognition occurs rapidly
2. Objects can be recognised from novel viewpoints
3. New examples of a known object can be recognised
4. Occluded objects can still be recognised
5. Objects can be recognised despite visual noise.

Question 23

The process of object recognition

Answer 23

Decompose objects into structures and their relations
Create abstract representations (i.e doesn’t look like the thing)
Compare to other representations stored in memory
Best match = recognition

Question 24

Viewer centred representations

Answer 24

-Idea that our mind stores multiple representations of an object
-Captures appearance of the object in individual moments (angle, visual noise, etc)
-Matching process involves rotating the current object until it ‘fits’ one of these pre-existing examples from the past.

Question 25

Object-centred representations

Answer 25

-Idea that objects re represented in a unitary form (one central representation)
-Based on the shape of the object
-Representation is independent of of viewpoint, visual noise, etc, therefore object centred.