Chapter 5 - Influences on Visual Perception

Question 1

What are the main factors that influence visual perception?

Answer 1

Physiology
Aging
Genetics

Question 2

Physiology influence on visual perception

Answer 2

If any components are damaged, deteriorates or is negatively impacted, the ability to visually perceive the world is compromised.
- Colour-blindness/deficient
Inability to distinguish between certain colours due to impaired or missing cones
- Achloropsia
Perceive only black and white
Lack of cone vision, but also neural pathway damage

Question 3

Aging examples of influence on visual perception

Answer 3

1. Presbyopia
2. Floaters
3. Cataracts
4. Age related macular degeneration
5. Glaucoma

Question 4

Examples of genetic influence on visual perception

Answer 4

1. Inherited visual disorders
2. Congenital visual disorders
3. Colour vision deficiency
4. Retinas pigmentosa

Question 5

Presbyopia

Answer 5

Loss of lens flexibility – the lens stretches
Loss of lens ‘bend-ability’ hence losing ‘focus-ability’
Irreversible

Question 6

Floaters

Answer 6

Tiny gel-like clumps of matter that float in the vitreous fluid surrounding the eyes
Starts in mid-40’s
Caused by deterioration of vitreous humor – little crystals form

Question 7

Cataracts

Answer 7

Break down of proteins leads to the formation of a cloudy lens
Causes blurred vision & difficulty seeing at night or in bright light
Protein breakdown is seen as a natural part of aging
Fixed by surgery and interocular lens implant

Question 8

Age related macular degeneration

Answer 8

Caused by deterioration & build up of grainy deposits in the macula
Inflammation & degeneration of the macula’s photoreceptor cells cause a blur spot in the centre of vision leading to a loss of detail

Question 9

Glaucoma

Answer 9

Optic nerve is damaged due to increased pressure in the eye (aqueous hum)
Results in loss of peripheral vision

Question 10

Examples of inherited visual disorders

Answer 10

Strabismus (cross eyed)
Amblyopia (the brain favours the other eye)
Astigmatism (the front surface of the eye is curved differently in one direction to the other)
Glaucoma
AMD (a blur spot in the centre of vision)

Question 11

What is Congenital visual disorders?

Answer 11

A disorder present at birth from genetic factors or arise during gestation

Question 12

Colour deficiency

Answer 12

More common in males, mutation of a gene on the X chromosome

Question 13

Retinas Pigmentosa

Answer 13

A degenerative disease - gradual loss of peripheral vision (tunnel)

Question 14

Examples of psychological influences

Answer 14

Past experiences
Context
Motivation
Emotion

Question 15

What is Perceptual Constancies?

Answer 15

the tendency to maintain a stable perception of a stimulus, although the properties of the image on the retina may change

Question 16

Size Constancy + Shape Constancy

Answer 16

Shape and size of the retinal image (reception, transduction, transmission) can change but it doesn’t change our perception (selection, organization, interpretation)

Question 17

The Gestalt Principals

Answer 17

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

Question 18

types of depth perception

Answer 18

Binocular and Monocular

Question 19

Depth Perception

Answer 19

The ability to accurately judge 3D space and distance by using cues in the environment

Question 20

Perceptual set

Answer 20

perceiving things in a certain way due to past experience, context, or emotional state

Question 21

Social influences on perception?

Answer 21

Cultural Skills; study by Hudson and Deregowski