Unit 3 Topic 2 - Visual Perception Flashcards
Describe the process of sensation in relation to vision (3.2.1.1)
Reception: stimulus energy is collected by eye
Transduction: stimulus energy is converted by the receptor cells into electrochemical nerve impulses
Transmission: receptor cells send the nerve impulses to the primary sensory cortex where specialised receptor cells respond as the process of perception begins
Describe the process of perception in relation to vision (3.2.1.1)
Selection: pick out the most important and meaningful stimuli to focus on
Organisiation: the information reaches the brain and is organised so we can make sense of it
Interpretation: our past experiences, motives, values and context give stimuli meaning
Differentiate between sensation and perception (3.2.1.1)
Sensation - biological, physiological, bodily processes
Perception - physiological, psychological
List and describe the biological influences of visual perception (3.2.1.2)
Ageing: ability to perceive and interpret changes
Genetics: heritable genetic disorders
Psychological Make-Up: damage or impairment of structures of the visual system - related to psychological structure of the eye
List and describe the psychological influences of visual perception (3.2.1.3)
Past Experiences: affect visual perception - significant personal meaning
Context: environment of the stimulus - immediate effect on our expectation
Motivation: we see what we want to see
Emotion: depends on our feelings
Define perceptual set (3.2.1.3)
- predisposition to perceive stimuli in a specific way
- interpreting what we see according to certain preconceptions
List and describe the perceptual constancies visual perception principles (3.2.1.3)
size constancy: maintain constant perception of an objects size
shape constancy: object maintains is shape despite change in perspective
List and describe the gestalt principles visual perception principles (3.2.1.3)
figure ground organisation: whats infront and behind
camouflage: figure blends with surroundings
closure: perceive object as whole when it is actually partially incomplete
similarity: individual parts are similar
proximity: stimulus pattern are close together
List and describe the depth perception visual perception principles (3.2.1.3)
Binocular Depth Cues:
- retinal disparity: each eye has slightly different view
- convergence: eyes move together to centre stimulus
Monocular Depth Cues:
- accommodation: adjust focus depending on position
- pictorial depth cues: 3D perceptions that are 2D
>linear perspective
>interposition
>texture gradient
>relative size
>height in vision field
Summarise
Hudson (1960)
(3.2.1.4)
AIM:
- determine the effect of culture on pictorial depth perception
METHOD:
- tested 85 factory workers from different backgrounds, educational levels and degrees of urbanisation
- showed picture of hunter and 2 animals
- image contained depth cues (overlapping + size constancy)
RESULTS:
- education and culture influence images
- higher education correctly identified ‘prey’
- children who attend school see 3D image
SIGNIFICANCE:
- culture does effect depth perception
Summarise
Deregoski (1972)
(3.2.1.4)
AIM:
- investigated whether pictures are seen and understood in the same way in different cultures, ‘are picture universal?’
METHOD:
- western v african cultures (indep. measures)
- exp 1: recreation of Hudson (1960)
- exp 2: construct the shown image
- exp 3: ambiguous trident
RESULTS:
- specific cultural skill which is learnt and not automatic
- africans thought images were only 2D
- westerns thought images were 3D
SIGNIFICANCE:
- different cultures influence the way in which images are seen and understood
Summarise
Deregoski, Muldrow and Muldrow (1972)
(3.2.1.4)
AIM:
- investigate recognition of pictures by remote populations who had trouble in recognising familiar objects
METHOD:
- used ‘low-land’ and ‘high-land’ groups which each had different exposures
- presented 3 pictures (standing buck, running leopard, Hudson image)
RESULTS:
- differences observed between groups (some groups had greater familiarity)
- concluded perception is mostly based on past experience or familiarity
- skill can be learnt
Explain the Müller-Lyer illusion (3.2.1.5)
The points are distanced at the same length apart however the illusion makes people believe one point is further away than the other
Relates to visual perception principle of closure
Explain the Ames Room illusion (3.2.1.5)
The room is trapezium shaped and designed to create false distance cues
When viewed through peephole (using one eye only), the room appears to be rectangular
The illusion restricts monocular vision which is the basis of the illusion
Explain the Ponzo Visual Illusions (3.2.1.5)
The yellow lines appear to be different sizes, however, they are the same length
Relates to visual perception principles of linear perspective and height in vision of field
