Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PSYC 212 > Chapter 9: Perceiving Colour > Flashcards

Chapter 9: Perceiving Colour Flashcards

1
Q

cerebral achromatopsia

A

a loss of colour vision caused by damage to the cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

mr i

A

a successful artist who suffered from cerebral achromatopsia following an automobile accident

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

colour deficiency

A

a condition in which people see fewer colours than people with normal colour vision and need to mix fewer wavelengths to match any other wavelength in the spectrum due to the genetic absence of one or more types of cone receptors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

are most people with colour deficiency bothered by their condition?

A

Most people who are born with this condition aren’t distributed by it because they have never experienced normal colour vision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

functions of colour perception

A
  • Signalling functions
  • Facilitate perceptual organization
  • Recognizing and identifying things we can see easily
  • Cue to emotions signalled by facial expressions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

why do some scientists think colour evolved?

A

to allow humans and monkeys to detect ripe fruits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

object colour experiment (Tanaka & Presnell, 1999)

A

participants were able to recognize appropriately coloured objects more rapidly than inappropriately colour objects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

ambiguous emotions experiment (Thorstenson et al., 2019)

A

found that when asked to rate the motions of ambiguous-emotion faces, participants were more likely to rate the face as expressing disgust when coloured green and as expressing anger when red

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Newton, 1704 experiment

A

Light entered through a hole in a window shade and then passed through a prism. The colours of the spectrum were then separated by passing them through holes in a board. Each colour of the spectrum then passed through a second prism. Different colours were bent by different amounts, demonstrating that white light is a mixture of differently coloured lights, which was split into its individual components by the prism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

key findings from Newton’s coloured beam experiment

A

1) the second prism didn’t change the colour appearance of any light that passed through it 2) the degree to which beams from each part of the spectrum were bent by the second prism was different

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

wavelength of violet rays

A

400-450 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

wavelength of blue rays

A

450-490 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

wavelength of green rays

A

500-575 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

wavelength of yellow rays

A

575-590 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

wavelength of orange rays

A

590-620 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

wavelength of red rays

A

620-700 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how is the colour of objects determined for opaque objects?

A

the wavelengths of light that are reflected from the object into our eyes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how is the colour of objects determined for transparent objects?

A

the wavelengths of light that are transmitted from the object into our eyes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

chromatic colours

A

colours with a hue, such as blue, yellow, red, or green

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

selective reflection

A

when an object reflects some wavelengths of the spectrum more than others

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

achromatic colours

A

colours without a hue, like white, black, and gray

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

reflectance curve

A

a plot showing the percentage of light reflected from an object vs. wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

selective transmission

A

when some wavelengths pass through visually transparent objects or substances and others do not

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is selective transmission associated with?

A

the perception of chromatic colour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

transmission curve

A

plots the percentage of light transmitted through a liquid or object at each wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what colour is perceived from short wavelengths?

A

blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what colour is perceived from medium wavelengths?

A

green

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what colour is perceived from long and medium wavelengths?

A

yellow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what colour is perceived from long wavelengths?

A

red

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what colour is perceived from long, medium, and short wavelengths?

A

white

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what happens to wavelengths when paints are mixed?

A

When mixed, both paints still absorb the same wavelengths they absorbed when alone. So, the only wavelengths reflected are those that are reflected by both paints in common

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Subtractive colour mixture

A

the creation of colours that occurs when pairs of different colours are mixed together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what happens when blue and yellow paint are mixed together?

A

a blob of blue paint absorbs all of its long-wavelength light, while a blob of yellow paint absorbs all of the short-wavelengths. When mixed together, the only wavelengths that survive are some of the medium wavelengths, which are associated with green

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what happens to wavelengths when lights are mixed?

A

When coloured lights are superimposed, all the light that is reflected from the surface by each light when alone is also reflected when the lights are superimposed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what happens when blue and yellow light are mixed together?

A

The light from a blue spot and from a yellow spot are both reflected in the observer’s eye. The added-together light contains short, medium, and long wavelengths, resulting in the perception of white

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

additive colour mixture

A

the creation of colours that occurs when lights of different colours are superimposed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

spectral colours

A

colours that appear in the visible spectrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

nonspectral colours

A

colours that do not appear in the spectrum because they are mixtures of other colours.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

how many colours can humans differentiate?

A

2.3 million

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

3 dimensions of colour

A

hue, saturation, value

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

hue

A

the experience of a chromatic colour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

saturation

A

the intensity of colour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

value (lightness)

A

the light-to-dark dimension of colour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

colour solid

A

a solid in which colours are organized in an orderly way based on their hue, saturation, and value

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Munsell colour system

A

Depiction of hue, saturation, and value developed by Albert Munsell in the early 1900s in which different hues are arranged around the circumference of a cylinder with perceptually similar hues placed next to each other.

46
Q

how did Newton believe vision occured?

A

rays of light falling upon the bottom of the eye excite vibrations in the retina, which are propagated along the fibres of the optic nerve, causing seeing

47
Q

Thomas Young’s criticism of Newton

A

Newton’s idea of a link between each size of vibration and each colour won’t work because a particular place on the retina can’t be capable of the large range of vibrations required

48
Q

trichromacy of colour vision

A

colour depends on the activation of three different receptor mechanisms

49
Q

Young-Helmholtz theory

A

another term for the trichromacy theory of colour vision

50
Q

colour-matching procedure

A

the procedure used in a colour-matching experiment where the experimenter presents a reference colour that is created by shining a single wavelength of light on a reference field. The observer then matches the reference colour by mixing different wavelengths of light in a comparison field.

51
Q

Maxwell’s colour-matching findings

A

any reference colour could be matched provided that observers were able to adjust the proportions of 3 wavelengths in the comparison field

52
Q

Microspectrophotometry

A

A technique in which a narrow beam of light is directed into a single visual receptor. This technique makes it possible to determine the pigment absorption spectra of single receptors

53
Q

Adaptive optimal imaging

A

a technique that makes it possible to look into a person’s eye and take pictures of the receptor array in the retina

54
Q

Aberrations

A

imperfections on the eye’s cornea and lens that distort light on its way to the retina

55
Q

Cone mosaic

A

arrangement of short, medium, and long-wavelength cones in a particular area of the retina

56
Q

Metamerism

A

a situation in which two physically different stimuli are perceptually identical because they both result in the same pattern of response in the three-cone receptors

57
Q

Metamers

A

the two identical fields in a colour-matching experiment

58
Q

Monochromatism

A

a rare form of colour blindness where people have no functioning cones. it is usually hereditary and occurs in about 10/ 1 million people

59
Q

Monochromats

A

people with no functioning cones; their vision is only created by rods, so they see shades of grey

60
Q

how many wavelengths do monochromats need to match any wavelength in the spectrum?

A

1

61
Q

Principle of univariance

A

absorption of a photon causes the same effect, no matter what the wavelength is (Any two wavelengths can cause the same response by changing the intensity)

62
Q

how many types of receptors does one need to perceive chromatic colour?

A

more than 1

63
Q

how much 480 nm light does the pigment absorb?

A

10%

64
Q

how much 600 nm light does the pigment absorb?

A

5%

65
Q

ratio of pigment 1 to pigment 2 for 480 nm light

A

10:2

66
Q

ratio of pigment 1 to pigment 2 for 600 nm light

A

5:10

67
Q

Dichromats

A

people who see just two types of cone pigment. they see chromatic colours, but can’t distinguish among all colours

68
Q

dichromats vs. trichromats

A

They can see chromatic colours, but confuse some colours that trichromats can distinguish

69
Q

trichromats

A

people who see all three types of cone pigment. they can discriminate among more wavelengths across the spectrum

70
Q

methods for determining colour deficiency if there are two receptor types

A
  • colour-matching procedure
  • Ishiara plates
71
Q

Ishihara plates

A

a display of coloured dots used to test for the presence of colour deficiency. The dots are coloured so that people with trichromatic colour vision can perceive numbers in the plate, but people with a colour deficiency cannot perceive these numbers, or perceive them differently than trichromats

72
Q

Unilateral dichromat

A

a person with trichromatic vision in one eye and dichromatic vision in the other

73
Q

why do we study unilateral dichromats?

A

Studying them allows us to understand the nature of dichromat’s colour vision

74
Q

neutral point

A

the wavelength at which dichromats perceive grey

75
Q

protanopia

A

a condition in which patients are missing the long-wavelength (red) pigment.

76
Q

colour perception in protanopes

A

As a result, the protanope perceives short-wavelength light as blue, perceives a grey neutral point at 492 m, and perceives yellow on the long-wavelength end of the spectrum.

77
Q

prevalence of protanopia

A

This condition is inherited through a gene located on the X chromosome and affects 1% of males and 0.02% of females.

78
Q

deuteranopia

A

a condition in which patients are missing the medium-wavelength (green) pigment.

79
Q

colour perception in deuteranopes

A

As a result, deuteranopes perceive blue at the short-wavelength end of the spectrum and see yellow at the long-wavelength end, with a neutral point at around 498 nm.

80
Q

prevalence of deuteranopia

A

This condition is inherited through a gene located on the X chromosome and affects 1% of males and 0.01% of females.

81
Q

tritanopia

A

a condition in which patients are missing the short-wavelength (blue) pigment.

82
Q

colour perception in tritanopes

A

Tritanopes see blue at the short wavelength end of the spectrum, red at the long wavelength, and a neutral point at 570 nm.

83
Q

prevalence of tritanopia

A

This condition affects 0.002% of males and 0.001% of females.

84
Q

what sex is more likely to be dichromats

A

Males are more likely to be dichromats because they only have 1 X chromosome

85
Q

Anomalous trichromatism

A

trichromats that mix wavelengths in different proportions from other trichromats. They are not as good at discriminating between wavelengths that are close together

86
Q

opponent-process theory

A

States that there are two pairs of chromatic colours: red-green & blue-yellow

87
Q

who proposed the opponent-process theory

A

Herring, 1878

88
Q

what colours were considered primary colours in the opponent-process theory?

A

Identified red, green, blue, and yellow as the primary colours and stated that other colours were made up of a combination of these colours

89
Q

colour circle

A

arranges perceptually similar colours next to each other around its perimeter such that complementary colours are across from one another

90
Q

what perceptual property does the colour circle account for?

A

Only accounts for hue, without considering variations in saturation or value

91
Q

complementary colours

A

colours that when combined, cancel each other out to create white or grey

92
Q

hue scaling

A

a procedure in which participants are given colours from around the hue circle and told to indicate the proportions of red, yellow, blue and green that they perceive in each colour. Herring found that each of his primary colours was perceived as pure

93
Q

unique hues

A

name given by Hering to what he proposed were the primary colours

94
Q

why wasn’t Herring’s theory widely accepted

A
  • The trichromatic theory was championed by Helmholtz who was more prestigious
  • Hering’s phenomenological evidence, which was based on describing the appearance of colours couldn’t compete with Maxwell’s quantitative colour-mixing data
  • There was no neural mechanism known that could respond in opposite ways
95
Q

hue cancellation

A

a procedure in which a subject is shown a monochromatic reference light and is asked to remove or cancel one of the colours in the reference light by adding a second wavelength. This procedure was used by Hurvich & Jameson in their research on the opponent-process theory

96
Q

opponent neurons

A

a neuron that has an excitatory response to wavelengths in one part of the spectrum and an inhibitory response to wavelengths in the other part of the spectrum

97
Q

significance of opponent neurons in colour perception

A

provided physiological evidence for the opponency of colour vision

98
Q

can the perception of opponent neurons be linked to the perception of colours?

A

no

99
Q

DeValois, 1960

A

recorded opponent neurons in the LGN of monkeys

100
Q

Circular single-opponent cortical neurons

A

firing rate increases when a medium-wavelength light is presented to the centre and decreases when a long-wavelength is presented to the surround

101
Q

Circular double-opponent cortical neurons

A

firing increases when medium-wavelength light is presented to the centre and long-wavelength light is presented to the surround. Firing decreases when the long-wavelength light is presented in the centre and when the medium-wavelength light is presented in the surround

102
Q

Side-by-side double-opponent cortical neurons

A

firing increases when a vertical medium wavelength is presented to the left side and when a vertical long wavelength is presented to the right side. Firing decreases when a vertical long-wavelength bar is presented to the left side and when a vertical medium-wavelength is presented to the right side.

103
Q

what does research suggest is an alternative function of opponent neurons?

A

Opponent neurons might instead indicate the difference in responding to pairs of cones

104
Q

Maxwell’s colour-matching conclusion

A

colour vision depends on three receptor mechanisms, each with different spectral sensitivities

105
Q

evidence for the trichromatic theory

A
  • Researchers measured absorption spectra of visual pigments in receptors (1960s) and found pigments that maximally responded to red, yellow, and blue
  • Later, researchers found genetic differences for coding proteins for the three pigments (1980s)
106
Q

what wavelength do short pigments respond maximally to?

A

419 nm

107
Q

what wavelength do medium pigments respond maximally to?

A

531 nm

108
Q

what wavelength do long pigments respond maximally to?

A

558 nm

109
Q

colour perception is based on ___

A

the response of the three different types of cones

110
Q

evidence for the opponent-process theory

A
  • colour afterimages
  • hue scalling
111
Q

where are opponent neurons found?

A

in the retina and the LGN

112
Q

which theory of colour vision is correct

A

both the trichromatic theory & opponent-process theory are correct. The trichromatic theory explains the responses of the cones in the retina.
The opponent-process theory explains neural response for cells connected to the cones further in the brain.

PSYC 212 (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions