Chapter 6: Other Sensory Systems

Question 1

The auditory receptors, known as hair cells, lie between …

Answer 1

the basilar membrane of the cochlea on one side and the tectorial membrane on the other

Question 2

Through which mechanism do we perceive low-frequency sounds (up to about 100 Hz)?

Answer 2

At low frequencies, the basilar membrane vibrates in synchrony with the sound waves, and each responding axon in the auditory nerve sends one action potential per sound wave

Question 3

How do we perceive middle-frequency sounds (100 to 4000 Hz)?

Answer 3

At intermediate frequencies, no single axon fires an action potential for each sound wave, but different axons fire for different waves, and so a volley (group) of axons fires for each wave

Question 4

How do we perceive high-frequency sounds (above 4000 Hz)?

Answer 4

At high frequencies, the sound causes maximum vibration for the hair cells at one location along the basilar membrane

Question 5

How is the auditory cortex like the visual cortex?

Answer 5

Any of the following: (a) Both vision and hearing have “what” and “where” pathways. (b) Areas in the superior temporal cortex analyze movement of both visual and auditory stimuli. Damage there can cause motion blindness or motion deafness. (c) The visual cortex is essential for visual imagery, and the primary auditory cortex is essential for auditory imagery. (d) Both the visual and auditory cortices need normal experience early in life to develop normal sensitivities.

Question 6

What is one way in which the auditory and visual cortices differ?

Answer 6

Damage to the primary visual cortex leaves someone blind, but damage to the primary auditory cortex merely impairs perception of complex sounds without making the person deaf

Question 7

What evidence suggests that human concepts rely on activation of the relevant sensory or motor areas of the cortex?

Answer 7

People with damage to the auditory cortex regard many sound-related words, such as “thunder,” as if they were nonwords.

Question 8

Which method of sound localization is more effective for an animal with a small head? Which is more effective for an animal with a large head? Why?

Answer 8

An animal with a small head localizes sounds mainly by differences in loudness because the ears are not far enough apart for differences in onset time to be useful. An animal with a large head localizes sounds mainly by differences in onset time because its ears are far apart and well suited to noting differences in phase or onset time.

Question 9

What evidence suggests that absolute pitch depends on special experiences?

Answer 9

Absolute pitch occurs almost entirely among people who had early musical training and is also more common among people who speak tonal languages, which require greater attention to pitch

Question 10

Which type of hearing loss—conductive deafness or nerve deafness—would be more common among members of rock bands and why?

Answer 10

Nerve deafness is common among rock band members because their frequent exposure to loud noises causes damage to the cells of the ear.

Question 11

Why do many older people have trouble hearing speech in spite of wearing hearing aids?

Answer 11

In some cases the language areas of the cortex have become less responsive. Also, auditory areas of the brain have decreased levels of inhibitory neurotransmitters, and the result is decreased ability to focus attention on one speaker in a noisy environment.

Question 12

Sarah is playing the piano. Normally, her dog doesn’t respond, but one particular song requires her to play a large number of higher notes. When she plays the high notes, her dog starts to howl because his ears are sensitive to the ____ of the high notes.
a. frequency
b. amplitude
c. volume
d. timbre

Answer 12

FREQUENCY

Correct. Higher notes on a piano have a higher frequency that we experience as higher pitches. Some animals, like Sarah’s dog, are sensitive to higher pitches versus lower pitches.

Question 13

When the stirrup vibrates the ____ window, it sets into motion the fluid in the _____.
a. round; hair cells
b. oval; hair cells
c. oval; cochlea
d. round; cochlea

Answer 13

Oval; Cochlea

Correct. There are three small bones in the inner ear that transfer the energy from the tympanic membrane to the inner ear. The final bone, the stirrup, vibrates against the oval window. This sets into motion the fluid inside the cochlea. The moving fluid displaces the hair cells, and they send signals to the brain that are interpreted as sound

Question 14

People with damage to the vestibular system have trouble reading street signs while walking. Why?

Answer 14

The vestibular system enables the brain to shift eye movements to compensate for changes in head position. Without feedback about head position, a person would not be able to correct the eye movements, and the experience would be like watching a jiggling book page.

Question 15

How do jalapeños produce a hot sensation?

Answer 15

Jalapeños and other hot peppers contain capsaicin, which stimulates receptors that are sensitive to painful heat.

Question 16

In what way is somatosensation several senses instead of one?

Answer 16

We have several types of receptors, sensitive to touch, heat, and so forth, and different parts of the somatosensory cortex respond to different kinds of skin stimulation.

Question 17

What evidence suggests that the somatosensory cortex is essential for the conscious perception of touch?

Answer 17

People are conscious of only those touch stimuli that produce sufficient arousal in the primary somatosensory cortex. Also, cells in the somatosensory cortex respond to what someone experiences, even if it is an illusion

Question 18

How do the responses to skin sensations differ between the somatosensory cortex and the insular cortex or the anterior cingulate cortex?

Answer 18

The somatosensory cortex is necessary for conscious perception of the location and type of skin sensation. The insular cortex and anterior cingulate cortex respond to the pleasantness.

Question 19

Suppose you suffer a cut through the spinal cord on the right side only. For the part of the body below that cut, will you lose pain sensation on the left side or the right side? Will you lose touch sensation on the left side or the right side?

Answer 19

You will lose pain sensation on the left side of the body because pain information crosses the spinal cord at once. You will lose touch sensation on the right side because touch pathways remain on the ipsilateral side until they reach the medulla

Question 20

In what ways are hurt feelings similar to physical pain?

Answer 20

Hurt feelings activate the cingulate cortex, just as physical pain does. Also, acetaminophen decreases hurt feelings (as well as pleasant feelings).

Question 21

Why do opiates relieve dull pain but not sharp pain?

Answer 21

Endorphins block messages from the thinnest pain fibers, conveying dull pain, but not from thicker fibers, carrying sharp pain

Question 22

How do the pain-relieving effects of cannabinoids differ from those of opiates?

Answer 22

Unlike opiates, cannabinoids exert most of their pain-relieving effects in the peripheral nervous system, not the CNS

Question 23

Which aspect of pain is most responsive to relief by placebos?

Answer 23

Placebos primarily relieve the emotional aspect of pain.

Question 24

How do ibuprofen and other nonsteroidal anti-inflammatory drugs decrease pain?

Answer 24

anti-inflammatory drugs block the release of chemicals from damaged tissues, which would otherwise magnify the effects of pain receptors

Question 25

In what way is chronic pain like memory?

Answer 25

One mechanism for memory is that repeated stimulation at a synapse increases its later response to the same type of stimulation. Similarly, repeated pain messages increase a synapse’s response to similar stimuli, and therefore the result is chronic pain.

Question 26

Do opiates increase or decrease itch sensations?

Answer 26

Opiates increase itch by blocking pain sensations. (Pain decreases itch.)

Question 27

Suppose someone suffers from constant itching. What kinds of drugs might help relieve it?

Answer 27

Two kinds of drugs might help—histamines or capsaicin—depending on the source of the itch.

Question 28

Taleesa took a pie out of the oven and let it cool for a while. She wants to test a bite, but before she does, she lightly touches it with her finger to see how hot it is. By touching it, her _____ will be able to let her know that it is now cool enough to eat.
a. free nerve endings
b. Meissner’s corpuscles
c. Merkel’s disks
d. Pacinian corpuscles

Answer 28

Free nerve endings
Correct. We have a variety of different somatosensory receptors that detect different types of sensations. In this case, Taleesa tested the temperature of her pie before eating it. Temperature is detected by the free nerve endings and information about it is sent to the brain.

Question 29

After spinning around a bat during a race, Frank tried running in a straight line. However, he was dizzy due to the fluid movement within his ____.
a. middle ear
b. cochlea
c. oval window
d. semicircular canals

Answer 29

Semicircular canals
Correct. The semicircular canals are filled with fluid and lined with hair cells. Movement of the head in any direction causes the fluid to move and push the hair cells sending the message that we are moving. After spinning, the fluid would continue moving for a few moments (making Frank dizzy). So Frank was having trouble walking because he was getting conflicting sensory information from his body.

Question 30

Information about touch is sent from the body to the primary somatosensory cortex located in the _____ cortex.
a. parietal
b. occipital
c. frontal
d. temporal

Answer 30

Parietal
Correct. The primary somatosensory cortex is located in the parietal lobe just adjacent to the primary motor cortex in the frontal lobe. Information about touch, pain, and pressure are sent via the thalamus to the primary somatosensory cortex.

Question 31

Suppose you find a new, unusual-tasting food. How could you determine whether we have a special receptor for that food or whether we taste it with a combination of the other known taste receptors?

Answer 31

You could test for cross-adaptation. If the new taste cross-adapts with others, then it uses the same receptors. If it does not cross-adapt, it may have a receptor of its own. Another possibility would be to find some procedure that blocks this taste without blocking other tastes

Question 32

If someone injected into your tongue a chemical that blocks the release of second messengers, how would it affect your taste experiences?

Answer 32

The chemical would block your experiences of sweet, bitter, and umami but should not prevent you from tasting salty and sour.

Question 33

In what way do olfactory receptors resemble metabotropic neurotransmitter receptors?

Answer 33

Like metabotropic neurotransmitter receptors, an olfactory receptor acts through a G protein that triggers further events within the cell.

Question 34

What is the mean life span of an olfactory receptor?

Answer 34

Most olfactory receptors survive a little more than a month before dying and being replaced.

Question 35

What factors contribute to individual differences in olfactory sensitivity?

Answer 35

People differ in olfactory sensitivity because of genetics, age, and gender.

Question 36

What is a major difference between olfactory receptors and those of the vomeronasal organ?

Answer 36

Olfactory receptors adapt quickly to a continuous odor, whereas receptors of the vomeronasal organ continue to respond. Also, vomeronasal sensations are apparently capable of influencing behavior even without being consciously perceived.

Question 37

What evidence indicates that people learn their synesthetic associations, at least in some cases?

Answer 37

Some people have letter-color synesthesia that matches the colors of refrigerator magnets they played with in childhood

Question 38

If someone reports seeing a particular letter in color, in what way is it different from a real color?

Answer 38

Someone who perceives a letter as yellow (when it is actually in black ink) can nevertheless see it on a yellow page

Question 39

Mammalian taste receptors are found inside _____ located in groups of 10 or more in _____ on the surface of the tongue.
a. taste buds; vesicles
b. papillae; vesicles
c. taste buds; papillae
d. papillae; taste buds

Answer 39

taste buds; papillae

Correct. Human taste receptors are found in specialized skin cells called taste buds. The taste buds are found in groups of at least 10. These groups are found in papillae on the surface of the tongue.
Taste

Question 40

Bianca is celebrating her birthday by having all of her favorite sweets: cake, ice cream, and soda. However, she notices that after she has eaten some cake, her ice cream doesn’t taste as sweet. What might explain this?
a. Hormones
b. Adaption
c. Tolerance
d. Cross-adaption

Answer 40

Adaptation

Correct. After exposure to one of the tastes (sweet, sour, salty, etc.), we tend to have receptor fatigue that is the result of adaption. This means that exposure to further items of the same type wouldn’t result in the same strength of experience. So after eating sweet cake, Bianca didn’t taste the sweet ice cream as strongly.

Question 41

Edward and his mother love the smell of freshly cut grass. However, recently Edward’s mother has noticed that she cannot smell the grass as well as Edward can. What is the best explanation for this difference between the two?
a. Edward’s mother is getting older.
b. Edward has better genes for smell.
c. Men have a stronger sense of smell.
d. Edward has finished going through puberty.

Answer 41

Edward’s mother is getting older

Correct. Normally as we age, our sense of smell decreases. In this case, Edward’s mother has likely had some sensitivity to smell decrease due to her age. However, she should follow up with her doctor just in case because a loss of smell can sometimes be an early symptom of Alzheimer’s disease.

Question 42

Check My Work
Nerve deafness can result from damage to the ____.
a. tympanic membrane, cochlea, or auditory nerve
b. stapes and pinna
c. cochlea, hair cells, or auditory nerve
d. malleus and auditory cortex

Answer 42

Cochlea, hair cells, or auditory nerve

Correct. There are two types of hearing loss. Conductive deafness (middle-ear deafness) can be temporary. Nerve deafness (inner-ear deafness) is the result of damage to the cochlea, the hair cells, or the auditory nerve. It can be a total loss or confined to a part of the cochlea.

Question 43

Why do we move the eye muscles with greater precision than the biceps muscles?

Answer 43

Each axon to the biceps muscles innervates about a hundred fibers; therefore, it is not possible to change the movement by a small amount. In contrast, an axon to the eye muscles innervates only about three fibers.

Question 44

Which transmitter causes a skeletal muscle to contract?

Answer 44

Acetylcholine. And remember that a muscle’s only movement is to contract.

Question 45

In what way are fish movements impaired in cold water?

Answer 45

Although a fish can move rapidly in cold water, it fatigues easily.

Question 46

Duck breast muscles are red (“dark meat”), whereas chicken breast muscles are white. Which species probably can fly for a longer time before fatiguing?

Answer 46

Ducks can fly great distances, as they often do during migration. The white muscle of a chicken breast has the power necessary to get a heavy body off the ground, but it fatigues rapidly. Chickens seldom fly far

Question 47

If you hold your arm straight out and someone pulls it down slightly, it quickly bounces back. Which proprioceptor is responsible?

Answer 47

The muscle spindle

Question 48

What is the function of Golgi tendon organs?

Answer 48

Golgi tendon organs respond to muscle tension and thereby prevent excessively strong muscle contractions.

Question 49

If Evie wants to move her arm, she needs her _____ muscle to bend the elbow and the _____ muscle to straighten it.
a. flexor; extensor
b. antagonistic; flexor
c. extensor; flexor
d. flexor; antagonistic

Answer 49

Flexor; Extensor

Correct. For Evie to move her arm, she needs to either bend her elbow (using her flexor muscles) or straighten it out (using her extensor muscles). Most movements like this are done using pairs of antagonistic muscles.

Question 50

Which of the following is an example of a ballistic movement?
a. Karen who is removing her hand from a hot pan
b. Rosia who is standing on one foot
c. Marion who is getting out of bed
d. Ryan who is holding a glass of water

Answer 50

Karen who is removing her hand from a hot pan

Correct. Ballistic movements (mainly reflexes for humans) are executed as a whole. This means that once Karen touches the hot pan and begins to move her hand, the entire movement will be executed.

Question 51

Consistent, automatic responses to stimuli are called _____.
a. motor programs
b. stretch spindles
c. central pattern generators
d. reflexes

Answer 51

Reflexes

Correct. Reflexes, like the stretch reflex, are consistent, automatic responses to stimuli. We generally think of them as involuntary because they are insensitive to reinforcements, punishments, and motivations.