Vision

Night-active species are more likely than day-active species to have:

A greater rod to cone ratio

Light energy converts 11-cis-retinal to:

All-trans-retinal

Cells in the retina that provide connections among themselves, as well as with bipolar and ganglion cells, are known as:

Amacrine cells

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

Amacrine cells

Which of the following is TRUE according to the law of specific nerve energies?

Any stimulation of the auditory nerve is perceived as sound

In comparison to cones, rods:

Are more sensitive to dim light

Foveal vision has:

Better acuity

In the most common form of color vision deficiency, people have difficulty distinguishing:

Between red and green

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

Bipolar cells

Parvocellular neurons most likely receive input from:

Bipolar cells that receive input from cones

The name of the point at which the optic nerve leaves the retina is called the:

Blind spot

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

The principle that allows you to perceive an orange shirt to be the same color under varying lighting conditions is known as:

Color constancy

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

Which of the following is NOT a factor in color vision deficiency?

Elongated shape of the eye

The law of specific nerve energies states that:

Every stimulation of the optic nerve is perceived as light

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

Most retinal cones are concentrated in the:

Fovea

The optic nerve is composed of axons from which of the following cells?

Ganglion

__ cells axons make up the optic nerve.

Ganglion

The bipolar cells send their messages to __, located closer to the eye.

Ganglion cells

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

Ganglion cells

After staring at your instructor's red shirt for an entire class period, the negative afterimage will most likely be:

Green

In humans, the optic nerves from the two eyes follow what pathway?

Half of the axons from each eye cross to the other side at the optic chiasm

The retinas of predatory birds such as hawks:

Have a greater density of receptors than do humans on the top half of the retina

How do the retinas of predatory birds, such as hawks, differ from the retinas of prey species, such as rats?

Hawks have greater density of receptors on the top half of their retinas than do rats

In the vertebrae retina, which cells are responsible for lateral inhibition?

Horizontal cells

The enhancement of contrast at the edge of an object is primarily due to lateral inhibition by the:

Horizontal cells

While light is striking a visual receptor, light begins also to strike the receptor next to it. What effect will this additional light have on the response of the first cell?

Inhibition

How does light excite a rod or cone?

It converts 11 cis-retinal into all-trans-retinal

Which of the following characterizes the fovea?

It has the greatest perception of detail

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

It is a sex-linked genetic disorder

Which of the following is TRUE related to peripheral vision?

It is easier to recognize single objects in the periphery that are not surrounded by other objects

If light shines in the receptive field of a bipolar cell of the visual system, what effect will it have on the activity of that cell?

It may excite or inhibit the cell

Branches of the optic nerve go directly to what areas of the brain?

Lateral geniculate and superior colliculus

Suppose someone has a genetic defect that prevents the formation of horizontal cells in the retina. Which visual phenomenon is most likely to be impaired?

Lateral inhibition

What is responsible for sharpening contrast at visual borders?

Lateral inhibition

The enhancement of contrast at the edge of an object is the result of:

Lateral inhibition in the retina

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

The ability to detect movement better than color in our peripheral vision is largely due to:

Magnocellular neurons in the periphery

What is the relationship of color blindness between males and females?

Males are more likely to be color blind

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

Midget

Why do humans perceive faint light better in the periphery of the eye?

More receptors in the periphery than in the fovea funnel input to each ganglion cell

Magnocellular cells are to __ as parvocellular cells are to __.

Movement; color

Axons from the lateral geniculate extend to which area of the cerebral cortex?

Occipital lobe

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

Which theory of color vision is best able to explain negative color afterimages?

Opponent-process theory

__ modify the __ sensitivity to different wavelengths of light.

Opsins; photopigments

The optic nerves from the right and left eye initially meet at the:

Optic chiasm

According to the trichromatic theory of color vision:

Our perception of color depends on the relative activity of three types of cones

Being able to detect fine details of a color painting would depend most on which of the following types of ganglion cells?

Parvocellular

Which ganglion cells, if any, are located mostly in or near the fovea?

Parvocellular

Small receptive fields are to __ cells as large receptive fields are to __ cells.

Parvocellular; magnocellular

Chemicals that release energy when struck by light are called:

Photopigments

__ are chemicals that release energy when struck by light

Photopigments

The receptive field of a receptor is the:

Point in space from which light strikes the receptor

Visual information from the lateral geniculate area goes to the:

Primary visual cortex

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

Pupil

Stimulating a receptor leads to either excitation or inhibition of a particular neuron; the receptor is part of that neuron's:

Receptive field

The point in space from which light strikes the receptor is called the:

Receptive field

In what order does visual information through the retina?

Receptor cells. bipolar cells, ganglion cells

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

Receptors are tightly packed there

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

According to the trichromatic theory of color vision, the most important factor in determining the color we see is the:

Relative activity of short, medium, and long wavelengths

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

Retinex

Which theory can best explain why people that are wearing yellow-colored glasses can still identify the color of a green apple?

Retinex theory

Peripheral vision mainly depends upon:

Rods

What are the two kinds of receptors in the retina?

Rods and cones

Horizontal cells receive their input from __; they spend output to __.

Rods and cones; bipolar cells

In comparison to the rods, cones are more:

Sensitive to detail

The primary visual cortex is also known as the:

Striate cortex

The lateral geniculate nucleus is part of the:

Thalamus

In the visual system, the __ and __ constantly feed information back and forth.

Thalamus; cortex

Blindsight refers to:

The ability to localize visual objects within an apparently blind visual field

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

The fovea

Cutting the optic nerve in front of the optic chiasm would result in blindness in __.

The left eye

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

The left half

All of the following are reasons why the fovea is well-suited for highly detailed vision EXCEPT:

The optic nerve connects there

Rods are to __ as cones are to __.

The periphery; the fovea

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

The right half

The blind spot in each eye is blind because:

There are no receptors there

Which of the following characterizes the blind spot?

There are no receptors there

According to the Young-Helmholtz theory, what is the basis for color vision?

Three kinds of cones

Initially, researchers determined how many receptors we have for determining color:

Through psychophysical observations

The primary visual cortex sends its information:

To area V2

In vertebrate retinas, receptors send their messages:

To bipolar cells within the retina

Where does the optic nerve send most of its information?

To the lateral geniculate

The fact that all color on older televisions were created by combining only three different colors of light supports the __ theory of color vision.

Trichromatic

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

The ability of some women to detect slightly finer discriminations of color than other women is most likely due to having:

Two types of long-wavelength cones

Cortical area __ appears to be where conscious visual perception occurs.

V1

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

Which theory emphasizes the idea that color vision depends on the relative responses of three kinds of cones?

Young-Helmholtz theory