Module 6.1

Why are men more likely to experience color vision deficiency than women?

It is a sex-linked genetic disorder.

____ are chemicals that release energy when struck by light.

Photopigments

Why does the fovea provide the clearest, most detailed visual information?

Receptors are tightly packed there.

Light energy converts 11-cis-retinal to:

all-trans-retinal.

Various types of ____ cells refine the input to ganglion cells, enabling them to respond specifically to shapes, movement, or other visual features.

amacrine cells

In comparison to cones, rods:

are more sensitive to dim light.

In the human retina, messages go from receptors at the back of the eye to ____.

bipolar cells

Based on the relative distribution of the three kinds of cones in the retina, which color of road sign would be most difficult to see from a distance?

blue

Light from above our head strikes the:

bottom half of the retina

Which receptors are responsible for the perception of color?

cones

According to the retinex theory, we perceive color by:

contrasting the activity in one area of the visual field with that of the others.

More than a century ago, researchers had evidence that the human retina contained three kinds of color-sensitive receptors. What was the basis of their evidence?

experiments on mixing colors of light together

Because blood vessels and ganglion cell axons are almost absent near the ____, it has nearly unimpeded vision.

fovea

The bipolar cells send their messages to ____, located closer to the center of the eye.

ganglion cells

The optic nerve is composed of axons from which kind of cell?

ganglion cells

Light is focused as it enters through which of the following structures?

lens and cornea

The most common form of color vision deficiency is due to:

long- and medium-wavelength cones making the same photopigment.

If you wanted to see a faint star at night, you should:

look slightly to one side.

Ganglion cells near the fovea in humans and other primates are called ____ ganglion cells.

midget

After you stare at a bright green object for a minute and look away, you see red. Which theory attempts to explain this finding?

opponent-process theory

According to the trichromatic theory of color vision:

our perception of color depends on the relative activity of three types of cones.

Light enters the eye through an opening in the center of the iris called the:

pupil

In what order does visual information pass through the retina?

receptor cells, bipolar cells, ganglion cells

Color constancy is the ability to:

recognize the color of an object despite changes in lighting.

Difficulty distinguishing between ____ and ____ is the most common form of color vision deficiency.

red; green

Color and brightness constancy are best explained by the ____ theory of color vision.

retinex

What are the two kinds of receptors in the retina?

rods and cones

If you want to see something in fine detail, you should focus the light on which part of your retina?

the fovea

Light from the right half of the world strikes what part of the retina?

the left half

Rods are to ____ as cones are to ____.

the periphery; the fovea

The blind spot in each eye is blind because:

there are no receptors there.

At the level of rods and cones, the ____ theory seems to fit best, while at the level of the bipolar cells, the ____ theory seems to fit best.

trichromatic; opponent process

According to the law of specific nerve energies, the brain tells the difference between one sensory modality and another by:

which neurons are active.

What is perceived when all types of cones are simultaneously and equally active?

white