Lecture 6 Flashcards
What is the bottom-up process of perception?
DATA DRIVEN
- Environmental simulation
- -sensory process–> - Sensation(being received): Retinal image (only sensory fragments of angles and lines)
- Perceptual Organisation(processes info): Figure seen as rectangle turned away away from you
- -Organisation, Depth, Constancy–> - Identification/Recognition: Recognised as member of picture category
What is the top down process of perception?
CONCEPTUALLY DRIVEN- by higher order processes
- Mental Processes
- - Expectation, beliefs,Knowledge, Memory, Language–> - Identification/Recognition: Recognised as member of picture category
What is perceptual organisation?
organisation of a continuous array of sensations into meaningful units
Perception is not fixed/absolute - single image can have multiple interpretations (old woman with big nose or young woman with necklace)
What are the 4 aspects of perceptual organisation?
- Form perception
- Depth or distance perception
- Motion perception
- Perceptual Constancy
What is Form perception?
Organises sensory information into meaningful shapes and patters
(giraffe picture)
Gestalt view
What is the Gestalt view?
The whole is more than the sum of the parts
What are the Gestalt principles?
Underlying principle: We tend organise visual elements into two groups or unified wholes
- The law of Proximity - group nearest elements - see rows not columns
- The law of Similarity - group most similar elements - see square of Os inside Xs, not mixed columns
- The law of Good Continuation - see lines as continuous even when interrupted - arrow piercing heart not separate 3 elements
- The law of Closure - fill in the gaps to experience as whole
- The law of Common Fate - Group objects moving in same direction - alternative rows moving apart
What is Distance or Depth perception?
The organisation of perception in 3 dimensions
Visual information provides important information about depth and distance (Monocular cues, Binocular cues and Motion parallax cues)
What are the 7x Monocular Depth perception cues?
Uses visual input form one eye
- Interposition
- Linear Perspective
- Texture Gradient
- Shading
- Aerial Perspective
- Familiar size
- Relative size
What are the 2x Binocular Depth perception cues?
Uses visual input integrated from the two eyes
Retinal disparity
Convergence
What are the 2x Motion Parallax Depth perception cues?
relative distance from viewer determines amount and direction of relative motion
see a car that is far away as Stationary even though it is moving towards you
Rods in retina and neurons are sensitive to motion
1. Eyes stationary and object moves
2. Eye moves with the object, keeping the object on the same place of the retina
What is retinal disparity?
Each eye gets a different picture of the world
The greater the difference between pictures the closer the object
What is convergence?
Eyes point inwards when looking towards close objects
Eyes move outwards when looking at distant objects
Cue about depth
What is perceptual constancy?
Ability to maintain an unchanging perception of an object despite variations in retinal image
Impossible images plays with perceptual constancy
What are the three main types of Perceptual constancy?
Size Constancy
Shape constancy
Lightness constancy