16. Sensation & Perception: Colour perception

Question 1

colour perceptions can help: (4)

Answer 1

1. find things
2. determine if fruit is ripe
3. spot & identify poisonous animals
4. identify a potential mate

Question 2

___ light is a mixture of all light wavelengths

Answer 2

WHITE

Question 3

light ____ ____ through an opaque object

Answer 3

CANNOT PASS

Question 4

colour of an opaque object is determined by the ___ it ____

Answer 4

LIGHT it REFLECTS

Question 5

if an opaque object reflects red light, it looks ___

Answer 5

RED

Question 6

colour of transparent objects is determined by the colour it ____

Answer 6

TRANSMITS

Question 7

in the Munsell colour system, colours are categorised by? (3)

Answer 7

1. value (lightness)
2. hue (colour)
3. chroma (saturation)

Question 8

photoreceptors in retina are… (2)

Answer 8

CONES & RODS

Question 9

name an impossible colour & state WHY its impossible

Answer 9

greenish red
- because they’re opposing colours

Question 10

rods are only active at ___ light levels

Answer 10

LOW

Question 11

Rods ___ distinguish b/w colours

Answer 11

CANNOT

Question 12

In normal light conditions, ___ are inactive & ___ are active

Answer 12

RODS inactive
CONES active

Question 13

____ allow you to see colour

Answer 13

CONES

Question 14

when it is TOO DARK, rods are ____ ____, they have to be ____

Answer 14

COMPLETELY FIRED
RECOVERED

Question 15

S cone wavelength & colour is…

Answer 15

419 nm, blue

Question 16

M cone wavelength & colour is…

Answer 16

531 nm, green

Question 17

L cone wavelength & colour is…

Answer 17

558 nm, red

Question 18

physically diff stimuli that appear the SAME are called…

Answer 18

METAMERS

Question 19

the 2 types of colour deficiency are…

Answer 19

1. Monochromatism
2. Dichromatism

Question 20

monochromats have:

Answer 20

• no functioning cones, only functioning rods
• can only see B&W
• very sensitive to light

Question 21

what to dichromats lack?

Answer 21

1 of the 3 types of cones

Question 22

what are the 3 types of dichromats?

Answer 22

1. Protanopes
2. Deuteranopes
3. Tritanopes

Question 23

cone absent, colour they can’t distinguish & can distinguish (PROTANOPIA)

Answer 23

• L ABSENT
• can’t distinguish red & green
• can distinguish blue & green, blue & red

Question 24

cone absent, colour they can’t distinguish & can distinguish (DEUTERANOPIA)

Answer 24

• M ABSENT
• can’t distinguish red & green
• can distinguish blue & green, blue & red

Question 25

cone absent, colour they can't distinguish & can distinguish (TRITANOPIA)

Answer 25

- S ABSENT - can't distinguish blue & green - can distinguish red & green, blue & red

Question 26

what are the 3 colour opponent channels?

Answer 26

1. red-green 2. blue-yellow 3. white-black

Question 27

list the 2 psychophysical evidence for colour channel existence

Answer 27

1. afterimages 2. impossible colours

Question 28

what colour we perceive is determined ___ ___ by the cones in our retina

Answer 28

NOT ONLY

Question 29

why are some colour combinations impossible?

Answer 29

- due to opponent process theory of colour vision - possible to have a bluish yellow (purple) however we CAN'T PERCEIVE this bluish yellow

Question 30

light reflected by an object is determined by the product of its ____ & the ____

Answer 30

reflectance & illumination (reflectance x illumination = reflected light)

Question 31

why do we see a green object if red light is shining onto it?

Answer 31

- cause we habituate to the colour - habituate to red, so everything appears GREENER than it otherwise would

Question 32

habituation is becoming ___ ____ to that colour

Answer 32

LESS SENSITIVE

Question 33

what are the 2 ways the visual system achieves colour consistency?

Answer 33

1. habituation 2. discounting the illuminant

Question 34

if same amounts of Blue is shined on a yellow object & vice versa...

Answer 34

humans are able to discount the blue & yellow illuminations - habituation can't occur - perceive it as grey