Deck 4: Sensation and Perception

Question 1

What structure changes its shape to focus our vision on objects at various distances?​

A)Pupil
B)​Fovea
C)​Lens
D)​Iris

Answer 1

​Lens

Question 2

Why is vision most detailed in the fovea?​

A)The fovea is the area of the retina that is closest to the pupil.
B)​The fovea is the area of the retina that is closest to the optic nerve.
C)​The fovea has the greatest receptor density and most numerous connections to the brain.
D)​The fovea is the only area of the retina with an equal ratio of rods to cones.

Answer 2

​The fovea has the greatest receptor density and most numerous connections to the brain.

Question 3

Which structure focuses light to the same degree,regardless of the distance to the object?​

A)The pupil​
B)​The cornea
C)​The iris
D)​The lens

Answer 3

​The cornea

Question 4

Which of the following is necessary for vision?​

A)Light comes into your eyes.
B)​You send sight rays from your eyes.
C)​Sight rays go out of your eyes and then come back in.
D)​You send out sight rays and light enters the eyes at the same time.

Question 5

Which of the following is true about animals with good color vision,such as most birds?​

A)They have excellent night vision.
B)​They have relatively poor detection of detail.
C)​They have many rods in their retina.
D)​They have many cones in their retina.

Question 6

Which of these is responsible for vision?​

A)Energy goes from the object to your eyes.
B)​Energy goes out of your eyes to the object.
C)​Energy travels both from your eyes and from the object.
D)​No energy passes in either direction.

Question 7

When you see something,what happens?​

A)Light goes into your eye.
B)​Rays come out of your eye.
C)​First, rays go out of your eye, and then light comes into it.
D)​Light goes into your eye and rays come out of it, simultaneously.

Question 8

The arrangement of receptors in the retina explains which of the following about hawks and owls?​

A)They can see in very faint light better than other species can.
B)​They can see greater distances than other species can.
C)​They can see objects below them better than objects above.
D)​They can see stationary objects better than they see moving objects.

Question 9

Which animal species,if any,can see farther than others?​

A)Humans can see farther than other species.​
B)​Hawks and eagles can see farther than other species.
C)​Predators such as cats can see farther than other species.
D)​All animals with vision can see equally far.

Question 10

Why does all light have a wavelength between about 400 and 700 nm?​

A)Wavelengths outside that range cannot travel very far through the air.​
B)​We define light as the wavelengths that stimulate our receptors.
C)​Wavelengths outside that range travel more slowly.
D)​The air acts as a prism to convert other wavelengths toward this range.

Question 11

In old age,the lens becomes more rigid.What is the effect on vision?​

A)Focusing on nearby objects becomes more difficult.​
B)​Shifting attention from one object to another becomes more difficult.
C)​Judging the speed of a moving object becomes more difficult.
D)​Recognizing faces becomes more difficult.

Question 12

How do we focus on objects at different distances?​

A)We shift between relying on cones and relying on rods.
B)​The pupil dilates or contracts.
C)​The lens changes its thickness.
D)​The iris becomes darker or lighter.

Question 13

Why do older people have difficulty focusing on nearby objects?​

A)The lens is more rigid.
B)​The pupil is slower to dilate or constrict.
C)​The action potentials from the retina have lower amplitude.
D)​The fovea increases in diameter.

Question 14

How does vision differ among animal species,if at all?​

A)Hawks, eagles, and other predatory birds can see farther than we can.
B)​Many birds and insects see ultraviolet radiation that we do not see.
C)​Cats and certain other species can see in total darkness.
D)​Among species that have vision at all, no differences exist.

Question 15

Which part of the retina,if any,has the greatest proportion of cones,relative to rods?​

A)The periphery​
B)​The fovea
C)​The area surrounding the blind spot
D)​All parts have equal proportions.

Question 16

Where are the rods and cones?​

A)In the cornea
B)​In the retina
C)​In the pupil
D)​In the fovea

Question 17

What makes the electromagnetic radiation from 400 nm to 700 nm visible?​

A)Those wavelengths have greater amplitude than other wavelengths.
B)​Those are the only wavelengths that can travel through the air.
C)​Those are the only wavelengths that reflect off objects.
D)​Our visual receptors are adapted to respond to those wavelengths.

Question 18

What happens to enable you to see something?​

A)Light bouncing off the object strikes your eyes.​
B)​You send rays from your eyes to the object.
C)​You send out rays from your eyes AND light strikes your eyes.
D)​Nothing passes in either direction between your eyes and the object.

Question 19

Which part of the retina,if any,has the best color vision?​

A)The periphery​
B)​The fovea
C)​The area surrounding the blind spot
D)​All areas have equally good color vision

Question 20

Is it true that cats can see in complete darkness? If so,how?​

A)Cats see by sending out powerful sight rays.
B)​Cats see by extrasensory means.
C)​Cats can see in the dark, but no one knows how they do it.
D)​No, vision in complete darkness is impossible.

Question 21

Compared to the fovea,the periphery of the retina is more sensitive to what?​

A)Color
B)​Detail
C)​Familiar objects
D)​Faint light

Question 22

Why do you see faint light better in the periphery of your vision than in the center?​

A)In the periphery, more receptors converge their input onto the next cells.
B)​The pupil casts a shadow over the center of the retina.
C)​The cornea focuses light mainly toward the periphery of the retina.
D)​The periphery has a higher percentage of cones.

Question 23

Suppose someone's retina contains only rods,no cones.What should we expect to find?​

A)This person has no perception of depth or distance.
B)​This person has trouble seeing anything in faint light.
C)​This person has poor perception of visual motion.
D)​This person has no perception of color.

Question 24

How does vision in the periphery differ from vision in the fovea?​

A)Vision in the periphery is more sensitive to detail.
B)​Vision in the periphery is more likely to be color-blind.
C)​Vision in the periphery is more likely to be nearsighted.
D)​Vision in the periphery is more likely to be farsighted.

Question 25

Where do the rods and cones send their messages (directly)?​

A)To the spinal cord
B)​To the brain
C)​To other cells within the retina
D)​To the eye on the other side of the head

Question 26

Why do you have better color vision in the fovea than in the periphery of the retina?​

A)The fovea has the highest density of cones.​
B)​In the fovea, more receptors pool their resources to excite the next cell.
C)​The fovea is the area of the retina that is closest to the pupil.
D)​The fovea has an equal ratio of rods to cones.

Question 27

Compared to the cones,which of these is more true of the rods?​

A)They are more abundant toward the periphery of the retina?
B)​They are more important for color vision.
C)​They are more important for perceiving detail.
D)​They are more important for daytime vision than for faint light.

Question 28

To see something in detail,what should you do?​

A)Keep the thickness of the lens as steady as possible.
B)​Focus slightly to the side of the object.
C)​Focus the object onto the periphery of the retina.
D)​Focus the object onto the fovea.

Question 29

Your vision adapts to faint light through what mechanism?​

A)The pupils constrict.
B)​Visual receptors build more of the molecules that respond to light.
C)​Visual receptors increase the velocity of their action potentials.
D)​The brain shifts its attention to enhance weak action potentials.

Question 30

After prolonged adaptation to dim light,where in your retina do you see best?​

A)Toward the periphery
B)​In the fovea
C)​In the area surrounding the blind spot
D)​In all parts of the retina equally

Question 31

What is true for vision in the periphery of the retina?​

A)It has high sensitivity to detail.
B)​It detects stationary objects but not movement.
C)​It has high sensitivity to faint light.
D)​It has high sensitivity to color.

Question 32

After you have thoroughly adapted to extremely dim light,which of these occurs?​

A)The objects you see seem more familiar than usual.
B)​Colors seem more distinct than usual.
C)​You see best in the periphery of your retina.
D)​You see best in the fovea.

Question 33

Why is it difficult to perceive color in faint light?​

A)Perception in faint light depends on faster than average action potentials.
B)​Perception in faint light depends on the fovea.
C)​Perception in faint light depends on the cones.
D)​Perception in faint light depends on the rods.

Question 34

On a dark night,why do you see a faint star better if you focus slightly to the side of it?​

A)Perception of faint light is better outside the fovea.
B)​The pupil casts a shadow onto the fovea.
C)​Cones are more abundant slightly outside the fovea than within it.
D)​Perception of detail is better outside the fovea.

Question 35

Why is color vision poor or absent toward the periphery of the retina?​

A)The periphery is farther from the optic nerve.
B)​The periphery is farther from the pupil.
C)​The periphery has few rods.
D)​The periphery has few cones.

Question 36

Which of the following is true for the rods of the retina?​

A)They are more important than the cones for perception in bright light.
B)​They contribute to detailed vision more than the cones do.
C)​They are primarily responsible for color vision.
D)​They are more abundant toward the periphery of the retina.

Question 37

Where in the retina are the rods most abundant?​

A)In the area surrounding the blind spot​
B)​In the fovea
C)​In the periphery
D)​In the optic nerve

Question 38

The fovea is specialized for perception of which aspects of vision?​

A)Color and detail
B)​Movement and faint light
C)​Objects above or below the viewer
D)​Faint light and large objects

Question 39

Why is color vision so poor in your extreme peripheral vision?​

A)The periphery of the retina consists almost entirely of rods.
B)​The cornea focuses colored light toward the fovea.
C)​Pigments in the periphery block certain wavelengths of light.
D)​Receptors in the periphery are too far from the pupil.

Question 40

The rods in the retina contribute most strongly to which of these?​

A)Recognition of faces
B)​Color vision
C)​Perception of visual detail
D)​Detection of faint light

Question 41

Why does the human retina have a blind spot?​

A)That point is the border between the area with cones and the areas with rods.
B)​The pupil casts a shadow over the retina at that point.
C)​The optic nerve exits from the retina at that point.
D)​Exposure to bright lights quickly damages that point in the retina.

Question 42

What makes the blind spot of the retina blind?​

A)The shape of the lens prevents light from focusing at that point.​
B)​Axons exit from the retina at that point.
C)​Inhibition from neighboring rods cancels out all the input from the cones.
D)​No blood vessels reach that part of the retina.

Question 43

Imagine you are staring at the center of a page with one eye,and an X is elsewhere on the page.You move the page toward your eye and away,and at one location the X seems to disappear.Why?​

A)The lens cannot focus fast enough to compensate for the movement.​
B)​You have a blind spot in your retina.
C)​You fail to attend to an unchanging stimulus.
D)​Your closed eye has inhibited input from the open eye.

Question 44

How does the anatomy of vision vary among people,if at all?​

A)Some people have receptors that respond to infrared wavelengths.
B)​Some people have far more cones than rods.
C)​Some people have far more connections between the retina and the brain.
D)​Except for blind people, the connections are virtually the same for everyone.

Question 45

The trichromatic (Young-Helmholtz)theory emphasizes which of these points?​

A)The brain compares the responses of one retinal area to that of another to infer colors.
B)​Certain brain cells increase response for some colors and decrease it for others.
C)​Three types of cones react differently depending on the wavelength of light.
D)​Red-green color deficiency is more common in men than it is in women.

Question 46

Some people have three times as many retina-to-brain connections as others do.What is the consequence for their vision,if any?​

A)They more precisely detect faint lights and tiny movements.
B)​They can see wavelengths beyond the usual range of human vision.
C)​They can see greater distances than other people can.
D)​Despite the anatomical difference, their vision is the same as anyone else's.

Question 47

How does the trichromatic theory (Young-Helmholtz theory)explain color vision?​

A)The brain compares responses in one retinal area to responses in another.
B)​The brain responds to the ratio of firing among three types of cones.
C)​The brain has a red-versus-green system and a yellow-versus-blue system.
D)​The brain compares the amplitude of an action potential to its velocity.

Question 48

From what point in the retina does the optic nerve exit?​

A)At the pupil
B)​At the fovea
C)​At the blind spot
D)​At all parts of the retina equally

Question 49

Red,yellow,and other colors differ physically in which regard?​

A)Intensity​
B)​Velocity
C)​Wavelength
D)​Polarization

Question 50

If you move farther from a paper with many tiny dots,the blue dots start to look black,although you can still see the tiny red and green dots.Why?​

A)You have fewer short-wavelength cones than the other types.
B)​Short-wavelength light excites cones but not rods.
C)​Short-wavelength light cannot travel as fast or as far.
D)​The lens cannot focus short-wavelength light as well as the other wavelengths.

Question 51

According to the trichromatic theory,how do we distinguish red from orange?​

A)The two colors produce different velocities of action potentials.
B)​The two colors produce different ratios of responses by types of cones.
C)​The two colors produce excitation in different areas of the brain.
D)​The two colors produce different durations of response by most of the cones.

Question 52

How many people have a blind spot in their eye?​

A)Only people who have stared directly at the sun​
B)​Only those who had oxygen insufficiency during birth
C)​Only those who had measles during childhood
D)​Everyone

Question 53

The optic nerve consists of axons from which type(s)of cell?​

A)Ganglion cells
B)​Cones
C)​Both cones and rods, equally
D)​Rods

Question 54

Which type of cone,if any,is the least numerous in the retina?​

A)The short-wavelength ("blue") cones are the least numerous.
B)​The medium-wavelength ("green") cones are the least numerous.
C)​The long-wavelength ("red") cones are the least numerous.
D)​The three types of cones are equally numerous.

Question 55

At the point where the optic nerve exits from the retina,what do we perceive?​

A)Only shades of black and white
B)​Brighter than usual colors
C)​Optical illusions
D)​Nothing at all

Question 56

What is the blind spot of the retina?​

A)It is a spot that is almost always damaged by oxygen deficit at birth.
B)​It is the part of the retina that is farthest from the fovea.
C)​It is the point where the lens cannot focus an image.
D)​It is the point where the optic nerve exits the retina.

Question 57

According to the trichromatic (Young-Helmholtz)theory,what causes perception of green?​

A)The activity of cones is greatest at a point between the fovea and the periphery.
B)​Most of the cones are firing at an intermediate frequency.
C)​The medium-wavelength cones are more active than the other ones.
D)​The velocity of action potentials from the retina is at an intermediate level.

Question 58

According to the trichromatic theory (Young-Helmholtz theory)of color vision,we perceive color by what means?​

A)Higher wavelengths of light produce action potentials with greater amplitudes.
B)​Higher wavelengths of light produce action potentials with higher velocities.
C)​Certain brain cells increase response for one color and decrease it for another.
D)​Three types of cones produce different ratios of response.

Question 59

What is present in the blind spot of the retina?​

A)The fovea
B)​Axons and blood vessels
C)​The shadow of the pupil
D)​Damaged cells

Question 60

According to the trichromatic (Young-Helmholtz)theory,when do we perceive white?​

A)We see white when the red-green and yellow-blue systems are at their neutral point.
B)​We see white when the velocity of action potentials approximates the normal distribution.
C)​We see white when the cones are twice as active as the rods.
D)​We see white when all types of cones are equally active.

Question 61

Which of the following does the retinex theory explain?​

A)Certain people can perceive finer distinctions of color than other people can.
B)​Changing the surrounding color changes the apparent color of an object.
C)​After staring at a red object for a minute and then looking away, we see green.
D)​We often remember colors as being brighter than they actually were.

Question 62

What does the retinex theory of color vision emphasize?​

A)Individual differences among people in how well they distinguish among colors
B)​Changes in an apparent color based on the colors of surrounding objects
C)​Cultural differences in how people describe colors
D)​Changes in people's memory of colors after various time intervals

Question 63

According to the trichromatic theory,what is the difference between bright orange and dim orange?​

A)Bright orange produces a different ratio of responses by the types of receptors.​
B)​Bright orange excites only one type of receptor.
C)​Bright orange excites the same receptors, but more strongly.
D)​Bright orange excites the rods in addition to cones.

Question 64

Which of the following supports the opponent process theory of color vision?​

A)If you stare at a blue object and look away, you see yellow.
B)​You see colors clearly in the center of vision but poorly toward the periphery.
C)​You can mix three colors of light to match any other color.
D)​Changing the color of the surround can change the apparent color of an object.

Question 65

Brightness contrast is responsible for which of these observations?​

A)An object seems brighter if it is next to something bright.
B)​An object seems brighter if it is next to something dark.
C)​An object seems brighter if it is motionless than if it is moving.
D)​An object seems brighter after you stare at it for a while.

Question 66

Exciting a particular bipolar cell in the retina produces a green sensation.According to the opponent-process theory,what sensation comes from inhibiting that cell?​

A)Yellow
B)​Red
C)​Blue
D)​Black

Question 67

The retinex theory of color vision tries to explain which of these observations?​

A)The apparent color of an object depends on the color of nearby objects.
B)​Most people who have trouble seeing green have trouble seeing red also.
C)​Color vision is best in the center of vision and declines toward the periphery.
D)​In faint light, we see little more than shades of white and gray.

Question 68

Which of these does the opponent-process theory explain better than the trichromatic theory?​

A)Negative afterimages
B)​Depth perception
C)​Face recognition
D)​Optical illusions

Question 69

The opponent-process theory of color vision explains which of these observations?​

A)From a greater distance, blue dots look black, although other small dots keep their color.
B)​You can easily recognize an object's color even while wearing tinted glasses.
C)​After you stare at a bright color for a minute, you look away and see a different color.
D)​Color vision becomes weaker and weaker toward the periphery of the retina.

Question 70

You form a negative afterimage of an object,and now you try to focus on a different part of the object.Why does the image move?​

A)Changing your fixation point causes different brain areas to become active.
B)​You are fatiguing a different set of receptors.
C)​Dominance shifts from one hemisphere to the other.
D)​The image is on your eyes themselves.

Question 71

Which of these is evidence favoring the retinex theory of color vision?​

A)After staring at a bright-colored image, we see a negative afterimage.
B)​From a distance, tiny blue dots appear to be black.
C)​It is possible to mix three colors to match any other color.
D)​We can still recognize all colors even if the lighting is green.

Question 72

Which of these is an example of "color constancy"?​

A)People in cultures throughout the world have words for red, green, yellow, and blue.
B)​You continue to see color shortly after the lights are turned off.
C)​A banana still looks yellow in a room illuminated with green light.
D)​The color seen with the left eye matches the color seen with the right eye.

Question 73

Which theory explains negative color afterimages?​

A)Opponent-process theory
B)​Retinex theory
C)​Trichromatic theory
D)​String theory

Question 74

According to the retinex theory of color vision,how do we perceive color?​

A)We compare the rates of responses by three types of cones.
B)​We compare an object to other objects in the scene.
C)​We detect whether a cell in the retina is increasing or decreasing its response.
D)​We compare the mean firing rate of cones to the mean rate of rods.

Question 75

Which of these is evidence favoring the opponent-process theory of color vision?​

A)After staring at a bright-colored image, we see a negative afterimage.
B)​From a distance, tiny blue dots appear to be black.
C)​It is possible to mix three colors to match any other color.
D)​We can still recognize all colors while wearing tinted glasses.

Question 76

Which of the following observations supports the retinex theory of color vision?​

A)On average, women perceive finer distinctions among colors than men do.
B)​After you stare at a colored object long enough, you look away and see a different color.
C)​The apparent color of an object depends on the surrounding objects.
D)​Colors seem brighter in the center of vision, and less bright toward the periphery.

Question 77

When certain neurons increase their firing rate,you see red.According to the opponent-process theory of color vision,what do you see when they inhibit their firing?​

A)Blue​
B)​Green
C)​White
D)​Yellow

Question 78

How does the opponent-process theory explain color vision?​

A)The brain compares responses in one retinal area to responses in another.
B)​The brain responds to the ratio of firing among three types of cones.
C)​The brain has a red-versus-green system and a yellow-versus-blue system.
D)​The brain compares the amplitude of an action potential to its velocity.

Question 79

Which of these would cause you to experience negative afterimages?​

A)Wear some tinted glasses and then take them off.
B)​Adapt to darkness for a minute and then look at a normal scene.
C)​Stare at a bright blue object for a minute and then look at a white surface.
D)​Remember what something looks like and then see the object itself.

Question 80

The opponent-process theory does better than the trichromatic theory at explaining which of these?​

A)Motion blindness
B)​Color constancy
C)​Negative afterimages
D)​Dark adaptation