Lecture 7: Perception

Question 1

Top-down processing

Answer 1

Using prior knowledge and experience to organise and interpret sensations —–> select specific features that meet expectations about stimulus —-> form perception

(processing with info you know)

Question 2

Bottom-up processing

Answer 2

Detect features of sensory data —> analyse specific features and combine component parts into more complex form —-> form perception

(processing with info you don’t know)

Question 3

Perceptual organisation

Answer 3

Organisation of a continuous array of sensory information into meaningful units and locates them in space

Question 4

Four aspects of perceptual organisation

Answer 4

1. Form perception
2. Depth or distance perception
3. Motion perception
4. Perceptual constancy

Question 5

Form perception

Answer 5

• Organises sensory information into meaningful shapes and patterns
• Perceptual set: formed when our expectations/context influences perception
• Divides our perception into a figure (prominent stimuli/object viewed) and ground (background against which we perceive the figure)

Question 6

Gestalt view

Answer 6

• The whole is more than the sum of the parts
• The underlying principle: We tend to organise visual elements into groups or unified wholes

Question 7

Gestalt principles (remember PSGCSF)

Answer 7

1. The law of proximity
2. The law of similarity
3. The law of good continuation
4. The law of closure
5. The law of simplicity
6. Form and ground

PSGCSF (Please send good cookies soon friend)

Question 8

The law of proximity

Answer 8

• Group nearest elements
• See columns not rows

Question 9

The law of similarity

Answer 9

• Group most similar elements
• See square of Os inside Xs, not mixed columns

Question 10

The law of good continuation

Answer 10

• See lines/patterns as continuous, rather than discontinuous elements
• X superimposed on a circle, not pieces of a pie

Question 11

The law of closure

Answer 11

Fill in the gaps to experience as whole

Question 12

The law of simplicity

Answer 12

Perceive simplest pattern possible

Question 13

Monocular depth perception cues

Answer 13

• Interposition
• Linear perspective
• Texture gradient
• Elevation
• Relative size
• Shading
• Aerial perspective
• Familiar size

Question 14

The Ames Room

Answer 14

Demonstrates the concept of misapplied size constancy (brain misinterprets the size of objects)

Question 15

Binocular disparity

Answer 15

• Each eye gets a different picture of the world
• The greater the difference between pictures, the closer the object

Question 16

Binocular convergence

Answer 16

• Eyes point inwards when looking toward close objects
• Eyes move outwards when looking at distant objects

Question 17

Motion perception

Answer 17

Perceive things as moving

Question 18

Perceptual constancy

Answer 18

Ability to maintain an unchanging perception of an object despite variations in retinal image

Question 19

Shape constancy

Answer 19

• Perceive true shape of object despite variations in shape in the retinal image
• Retinal image different from each position but still perceive as rectangle

Question 20

Size constancy

Answer 20

• Ability to perceive the true size of an object despite variations in the size of the retinal image
  Closer size = larger image on retina

Question 21

Colour constancy

Answer 21

Tendency to perceive whiteness, greyness, blackness of objects across changing levels of illumination

Question 22

The role of attention in perception

Answer 22

Inattentional blindness: Failure to perceive a prominent object because attention is on another task

Change blindness: Failure to perceive changes in a scene when there is a momentary interruption to views of that scene