Sensation & Perception Chapter 9

When you go to pick strawberries, you are easily able to separate the ripe red berries from the green foliage, the

white blossoms and the green, still-forming berries. This has led to the suggestion that _____.

color vision may have evolved for the express purpose of detecting fruit

A monkey with good color vision _____.

would have a better chance of surviving than a color-blind monkey

Adding more white to a color changes the color's _____.

saturation

The basic colors in the color circle are _____.

red, green, blue, and yellow

By changing _____, we can create about a million (or more) discriminable colors.

saturation, value, and hue

The reflectance curve is a plot of the light reflected off a surface as a function of _____.

wavelength

The reflectance curve for a white piece of paper would reflect _____.

long, medium and short wavelengths equally

The reflectance curve for a purple piece of paper will reflect _____.

long and short wavelengths

Yellow and blue light is projected on a white screen. What color will the screen appear to be?

white

Light that is mixed is referred to as a(n) _____.

additive color mixture

Paint that is mixed is referred to as a(n) _____.

subtractive color mixture

Blue and yellow paints mixed together yield _____.

green

The major theories of color vision were first proposed _____.

in the 1800s, based on behavioral evidence only

The trichromatic theory of color vision is also known as the _____ theory.

Young-Helmholtz

Color matching experiments show that if a person with full color vision is given at least ____ wavelengths to mix

together, the person can match any single wavelength.

three

The trichromatic theory of color vision states that color perception is due to _____.

the pattern of activity in three different receptor mechanisms

The maximum absorption for the short-wavelength cone pigment is at ____ nm.

419

The maximum absorption for the long-wavelength cone pigment is at ____ nm.

558

The pattern of firing of receptor activity in response to red would be _____.

little firing from the S receptor, a moderate firing from the M receptor, and large firing from the L receptor

Two stimuli that are physically different, but are perceptually identical, are called _____.

metamers

The principle of _____ helps explain why a person with only one visual pigment can see all wavelengths as the same

color (i.e., shade of gray) if light intensity is adjusted appropriately.

univariance

In order to distinguish between wavelengths independent of light intensity, one must have at least _____visual

pigment(s).

two

A monochromat experiences _____.

black, white, and grays

A unilateral dichromat _____.

has trichromatic vision in one eye and dichromatic vision in the other eye

Which of the following statements is TRUE about dichromatism?

Males are more likely to be dichromats than females.

The neutral point for protonopes is approximately ___ nm.

492

Physiological evidence shows that deuteranopes do not have the _____ wavelength cone pigment.

medium

The rarest form of dichromatism is _____.

tritanopia

Which of the following is behavioral support for the "opponent-process theory"?

color afterimages

Nora adapts to a yellow stimulus for about 30 seconds. She will then see an afterimage that appears to be _____.

blue

Dr. Lanzilotti wants to create a stimulus that will produce an afterimage of a red heart shape against a white

background. He should make the heart _____ and the background _____.

green; black

Which of the following is an opponent mechanism proposed by Hering?

Red (+); Green (-)

Hering's support for opponent-process theory was _____ in nature.

phenomenological

Opponent neurons found in _____ provide physiological support for the opponent-process theory.

both the retina and LGN

Which statement below best describes the current consensus on the theories of color vision?

The physiology of the cone receptors and the discovery of opponent cells in the retina and LGN show that both

theories are correct.

The case of "Mr. I," described in the beginning of the chapter, supports the idea that color is processed in _____.

a "color center" in the cortex

Cerebral achromatopsia is when a person _____.

has normal cone functioning, but cannot experience color due to a brain injury

The wavelength distributions from an incandescent light bulb and from sunlight are _____.

different, with the incandescent light bulb distribution having much higher amounts of energy at long

wavelengths

According to researcher Dorthea Jameson, "A blue bird would not be mistaken for a goldfinch if it were brought

indoors." This supports the concept of _____.

color constancy

Uchikawa et al. demonstrated how _____ can explain why color constancy occurs.

chromatic adaptation

Mark enters a supermarket that is lit by red lights. After fifteen minutes he enters the produce section and finds some

red apples to purchase. Mark is able to see these apples as red because he has undergone _____.

chromatic adaptation

Color constancy works best when _____.

a color object is surrounded by many different colors

Which of the following is a finding that demonstrates the phenomenon of memory color?

Participants perceive a 620-nm pattern as being "redder" if that pattern has the shape of a stop sign rather than

a mushroom shape.

Ikya looks at a white surface under sunlight conditions and she perceives it to be white. When she looks at the white

surface under a tungsten light, it looks _____ to her.

white

According to the ratio principle, _____.

lightness constancy will occur as long as the ratio of light reflected from a white surface and a black surface

remain constant

The edge between a dark shadow and an illuminated checkerboard is a(n) _____.

illumination edge

If you cover the penumbra with a black marker, the perception of the border _____.

changes from an illumination edge to a reflectance edge

If you look at a folded index card though a pinhole, you see the border as a(n) _____ because the card looks _____.

reflectance edge; flat

Newton's quote, "The rays ...are not colored", means that _____.

colors are created by our perceptual system

The absorption curves for honeybee visual pigments are _____.

nearly identical to those of humans

Bornstein et al. habituated a four-month-old infants to a 510 nm ("green") stimulus, then presented a 480nm ("blue")

stimulus or a 540nm ("green") stimulus. The infants in this study dishabituated to _____

the 480 nm stimulus only