ch 9 - perceiving color

Question 1

Describe the 4 functions of color perception

Answer 1

Color signals help us classify and identify objects.
Color facilitates the perceptual organization of elements into objects
Color vision may provide an evolutionary advantage in foraging for food.
Color vision can also be a cue to emotions signaled by facial expressions

Question 2

how do wavelengths affect our color experience

Answer 2

Colors of the spectrum were associated with different wavelengths of light.

We perceive colors bc the light in each part of the spectrum are defined by different physical properties

Question 3

short wave lengths

Answer 3

blue

Question 4

medium wavelengths

Answer 4

green

Question 5

Long and medium waves

Answer 5

yellow

Question 6

long wavelength

Answer 6

red

Question 7

long/medium/short waves

Answer 7

white

Question 8

selective reflection

Answer 8

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

Question 9

chromatic colors

Answer 9

Color with hue, such as blue, yellow, red, or green.

• occur as a result of selective reflection

Question 10

achromatic colors

Answer 10

black, white, and grays

Question 11

selective transmission

Answer 11

only some wavelengths pass through the object or substance

• the color for things such as liquids, plastics and glass

Question 12

Reflectance curves

Answer 12

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

Question 13

subtractive color mix

Answer 13

mixing paints

Question 14

how does subtractive color mixing work

Answer 14

Because the blue and yellow blobs subtract all of the wavelengths except some that are associated with green, mixing paint is called a SUBTRACTIVE COLOR MIXTURE

Question 15

additive color mixture

Answer 15

mixing lights

Question 16

how does additive color mixture work

Answer 16

Because mixing lights involves adding up the wavelengths of each light in the mixture, mixing lights is called an = ADDITIVE COLOR MIXTURE

Question 17

what are the 6 perceptual dimensions of color?

Answer 17

spectral and nonspectral colors, hues, saturation, value, and lightness

Question 18

spectral colors

Answer 18

colors that appear in the visible spectrum (ROYGBIV)

Question 19

nonspectral colors

Answer 19

colors that do not appear in the spectrum because they are a mixture of other colors, such as magenta (blue+red

Question 20

hues

Answer 20

experience of a chromatic color

Question 21

saturation

Answer 21

intensity of color

Question 22

value

Answer 22

The lightness or darkness of a color

Question 23

lightness

Answer 23

perception of shades ranging from white to gray to black

Question 24

Trichromacy of color vision

Answer 24

our perception of color is determined by the ratio of activity in 3 receptor mechanisms. human eyes only perceive 3 colors of light: red, blue, and green. The wavelengths of these three colors can be combined to create every color on the visible light spectrum.

Question 25

metamerism

Answer 25

The situation in which two physically different stimuli are perceptually identical

In vision, this refers to two lights with different wavelength distributions that are perceived as having the same color.

Question 26

opponent process theory of color vision

Answer 26

our perception of color is determined by the activity of 2 opponent mechanisms - a B-Y mechanism and an R-G mechanism

Question 27

behavioral evidence for opponent process theory of color

Answer 27

color circles, primary colors, hue scaling

Question 28

color circle

Answer 28

Perceptually similar colors located next to each other and arranged in a circle

Question 29

primary colors

Answer 29

red, yellow, blue, green

Question 30

hue scaling

Answer 30

a procedure in which participants were given colors from around the hue circle and told to indicate the proportions of red, yellow, blue, and green they perceive in each color

Question 31

physiological support for opponent process theory of color

Answer 31

opponent neurons: neurons that respond with an excitatory response to light from one part of the spectrum and with an inhibitory response to light from another part