Chapter 5 Sensation, Myers Psychology 8e

CHAPTER OVERVIEW

Sensation refers to the process by which we detectphysical energy from the environment and encode itas neural signals. This chapter describes the senses ofvision, hearing, taste, touch, smell, kinesthesis, andthe vestibular sense. It also presents research findingsfrom studies of subliminal stimulation.

In this chapter there are many terms to learn andseveral theories you must understand. Many of theterms are related to the structure of the eye, ear, andother sensory receptors. Doing the chapter reviewseveral times, labeling the diagrams, and rehearsingthe material frequently will help you to memorizethese structures and their functions. The theories discussed include the signal detection, Young-Helmholtz three-color and opponent-process theoriesof color vision, and the frequency and place theoriesof pitch. As you study these theories, concentrate onunderstanding the strengths and weaknesses (if any)of each.

NOTE: Answer guidelines for all Chapter 5 questionsbegin on page 145.

CHAPTER REVIEW

First, skim each section, noting headings and boldfaceitems. After you have read the section, review eachobjective by answering the fill-in and essay-typequestions that follow it. As you proceed, evaluateyour performance by consulting the answers begin-ning on page 145. Do not continue with the next sec-tion until you understand each answer. If you needto, review or reread the section in the textbook beforecontinuing.

Introduction (pp. 197–198)

Objective 1: Contrast sensation and perception, andexplain the difference between bottom-up and top-down processing.

1. The process by which we detect physical energyfrom the environment and encode it as neural signals is . The process bywhich sensations are selected, organized, andinterpreted is .

2. Sensory analysis, which starts at the entry leveland works up, is called -

.Perceptual analysis, which works from our expe-rience and expectations, is called

-.

3. The perceptual disorder in which a person haslost the ability to recognize familiar faces is

.

129

David Myers at times uses idioms that are un-familiar to some readers. If you do not knowthe meaning of the following expression in thecontext in which it appears in the text, refer topage 154 for an explanation: . . . in a mirror sheis again stumped.

Sensation 5:

Sensing the World: Some Basic Principles(pp. 198–203)

Objective 2: Distinguish between absolute and differ-ence thresholds, and discuss whether we can sensestimuli below our absolute threshold and be influ-enced by them.

1. The study of relationships between the physicalcharacteristics of stimuli and our psychologicalexperience of them is .

2. The refers to the minimum stimulation necessary for astimulus to be detected percent of the time.

3. The theory of led to the concept that

absolute thresholds depend not only on thestrength of the signal but also on a person’s

state.

4. Some entrepreneurs claim that exposure to“below threshold,” or ,stimuli can be persuasive, but their claims areprobably unwarranted.

5. Some weak stimuli may trigger in our sensoryreceptors a response that is processed by thebrain, even though the response doesn’t cross thethreshold into awareness.

6. Under certain conditions, an invisible image orword can a person’sresponse to a later question. The

illustrates that much of ourinformation processing occurs .

7. The minimum difference required to distinguishtwo stimuli 50 percent of the time is called the

.Another term for this value is the

.

8. The principle that the difference threshold is not aconstant amount, but a constant proportion, isknown as

. The proportion dependson the .

Objective 3: Describe sensory adaptation, andexplain how we benefit from being unaware ofchanging stimuli.

9. After constant exposure to an unchanging stimu-lus, the receptor cells of our senses begin to fireless vigorously; this phenomenon is called

.

10. This phenomenon illustrates that sensation isdesigned to focus on changes in the environment.

Explain why sensory adaptation is beneficial.

Vision (pp. 204–215)

Objective 4: Define transduction, and specify the formof energy our visual system converts into the neuralmessages our brain can interpret.

1. Stimulus energy is converted into messages through the

process of sensory .

2. The visible spectrum of light is a small portion ofthe larger spectrum of radiation.

3. The distance from one light wave peak to the nextis called . This value

If you do not know the meaning of any of thefollowing words, phrases, or expressions in thecontext in which they appear in the text, referto pages 154–155 for an explanation: blind spot;Rods have no such hotline; Holy Grail; blindsight;Color, like all aspects of vision, . . . the theater ofour brains.

130 Chapter 5 Sensation

If you do not know the meaning of any of thefollowing words, phrases, or expressions in thecontext in which they appear in the text, referto page 154 for an explanation: A frog couldstarve to death knee-deep in motionless flies; Theshades on our senses are open just a crack; thefaintest whimper from the cradle; “satanic mes-sages”; hucksters; price hike . . . to raise the eye-brows; So everywhere that Mary looks, the scene issure to go.

determines the wave’s color, or.

4. The amount of energy in light waves, or, determined by a wave’s , or height, influences the of a light.

Objective 5: Describe the major structures of the eye,and explain how they guide an incoming ray of lighttoward the eye’s receptor cells.

5. Light enters the eye through the , then passes through a

small opening called the ;the size of this opening is controlled by the colored .

6. By changing its curvature, thecan focus the image of an

object onto the , the light-sensitive inner surface of the eye.

7. The process by which the lens changes shape tofocus images is called .Clarity, or sharpness, of vision is called

.

8. In nearsightedness, light rays from(nearby/distant) objects

converge (in front of/inback of) the retina, rather than on it, and

(nearby/distant) objects are seen more clearly than

(nearby/distant) objects. Infarsightedness, light rays from (nearby/distant) objects converge (in front of/in back of) the retina, and

(nearby/distant) objects areseen more clearly than (nearby/distant) objects.

Objective 6: Contrast the two types of receptor cellsin the retina, and describe the retina’s reaction tolight.

9. The retina’s receptor cells are theand .

10. The neural signals produced in the rods andcones activate the neighboring

cells, which then activate a

network of cells. The axonsof ganglion cells converge to form the

,which carries the visual information to the

.

11. Where this nerve leaves the eye, there are noreceptors; thus the area is called the

.

12. Most cones are clustered around the retina’spoint of central focus, called the

, whereas the rods are con-centrated in more regions of the retina. Many cones have their own

cells to communicate withthe visual cortex.

13. It is the (rods/cones) of theeye that permit the perception of color, whereas

(rods/cones) enable black-and-white vision.

14. Unlike cones, in dim light the rods are(sensitive/insensitive).

Adapting to a darkened room will take the retinaapproximately minutes.

Objective 7: Discuss the different levels of processingthat occur as information travels from the retina tothe brain’s cortex.

15. Visual information percolates through progres-sively more levels. In thebrain, it is routed by the tohigher-level brain areas. Hubel and Wiesel dis-covered that certain neurons in the

of the brain respond only tospecific features of what is viewed. They calledthese neurons

.

16. Feature detectors pass their information to higher-level brain cells in the brain, including anarea in the cortex, whichresponds to specific visual scenes. Research hasshown that in monkey brains such cells specializein responding to a specific

, , , or

.

Vision 131

Researchers have also identified nerve cells thatmay respond or not, depending on how a monkey a given image.

Objective 8: Define parallel processing, and discuss itsrole in visual information processing.

17. The brain achieves its remarkable speed in visualperception by processing several subdivisions ofa stimulus (simultaneous-ly/sequentially). This procedure, called

, mayexplain why people who have suffered a strokemay lose just one aspect of vision. Other brain-damaged people may demonstrate

by responding to a stimulusthat is not consciously perceived.

18. Once the distributed parts of the brain haveprocessed sensory stimuli, EEG recordings reveala moment of neural , lastingfor about a fourth of a second and creating

waves. Other senses processinformation with (similar/slower/faster) speed and intricacy.

Objective 9: Explain how the Young-Helmholtz andopponent-process theories help us understand colorvision.

19. An object appears to be red in color because itthe long wavelengths of red

and because of our mental of the color.

20. One out of every 50 people is color deficient; thisis usually a male because the defect is genetically

- .

21. According to the -

theory, the eyes have three types of color receptors: one reacts most strongly to

, one to , and one to. Mixing lights, as Young

and von Helmholtz did, is color mixing, unlike mixing paints, which is

.

22. After staring at a green square for a while, youwill see the color red, its

color, as an .

23. Hering’s theory of color vision is called the-

theory. According to this theory, after visualinformation leaves the receptors it is analyzed interms of pairs of opposing colors:

versus , versus ,

and also versus .

Summarize the two stages of color processing.

Objective 10: Explain the importance of color con-stancy.

24. The experience of color depends on thein which an object is seen.

25. In an unvarying context, a familiar object will beperceived as having consistent color, even as thelight changes. This phenomenon is called

.

26. We see color as a result of our brains’ computa-tions of the light by anyobject relative to its

.

Hearing (pp. 215–224)


If you do not know the meaning of any of thefollowing words, phrases, or expressions in thecontext in which they appear in the text, referto page 155 for an explanation: sensitive to faintsounds, an obvious boon; A piccolo produces muchshorter, faster sound waves than does a tuba; ear-lids; If a car to the right honks; cock your head; theculprits are . . . ear-splitting noise or music.

Objective 11: Describe the pressure waves we experi-ence as sound.

1. The stimulus for hearing, or, is sound waves, created by

the compression and expansion of.

2. The amplitude of a sound wave determines thesound’s .

3. The pitch of a sound is derived from theof its wave.

4. Sound energy is measured in units called. The absolute threshold for

hearing is arbitrarily defined as such units.

Objective 12: Describe the three regions of the ear,and outline the series of events that triggers the elec-trical impulses sent to the brain.

5. The ear is divided into three main parts: theear, theear, and theear.

6. The outer ear channels sound waves toward the, a tight membrane that then

vibrates.

7. The middle ear transmits the vibrations through apiston made of three small bones: the

, , and .

8. In the inner ear, a coiled tube called thecontains the receptor cells

for hearing. The incoming vibrations cause the to

vibrate the fluid that fills the tube, which causesripples in the

, which is lined with . This

movement triggers impulses in adjacent nervefibers that converge to form the auditory nerve,which carries the neural messages (via the

) to the lobe’s auditory cortex. The brain interprets loud-ness from the of hair cells asound activates.

9. (Close-Up) On tasks requiring alert performance,people in noisy environments work

(more/less) efficiently.People who live in noisy environments suffer ele-vated rates of -related disor-ders such as

, , and

.Noise is especially stressful when it is

or .

Objective 13: Contrast place and frequency theories,and explain how they help us to understand pitchperception.

10. One theory of pitch perception proposes that dif-ferent pitches activate different places on thecochlea’s basilar membrane; this is the

theory. This theory has dif-ficulty accounting for how we hear

-pitched sounds, which donot have such localized effects.

11. A second theory proposes that neural impulses,sent to the brain at the same frequency as thesound wave, allow the perception of differentpitches. This is the theory.This theory fails to account for the perception of

-pitched sounds, becauseindividual neurons cannot fire faster than

times per second.

12. For the higher pitches, cells may alternate theirfiring to match the sound’s frequency, accordingto the principle.

Objective 14: Describe how we pinpoint sounds.

13. We locate a sound by sensing differences in theand

with which it reaches our ears.

14. A sound that comes from directly ahead will be(easier/harder) to locate

than a sound that comes from off to one side.

15. As with visual information, the brain usesas

specialized neural teams work on different audi-tory tasks simultaneously.

Hearing 133


Objective 15: Contrast the two types of hearing loss,and describe some of their causes.

16. Problems in the mechanical conduction of soundwaves through the outer or middle ear may cause

.

17. Damage to the cochlea’s hair cell receptors ortheir associated auditory nerves can cause

hearing loss. It may becaused by disease, but more often it results fromthe biological changes linked with

and prolonged exposure toear-splitting noise or music.

18. Scientists have discovered ways to hair cell regeneration.

Objective 16: Describe how cochlear implants func-tion, and explain why Deaf culture advocates objectto these devices.

19. An electronic device that restores hearing amongnerve-deafened people is a

.

20. Advocates of object to the use of these

implants on before theyhave learned to . The basisfor their argument is that deafness is not a

.

21. Sign language (is/is not) acomplete language, (with/without) its own grammar, syntax, andsemantics. Those who learn only sign languageduring childhood (have/donot have) difficulty later learning to read andwrite. People who lose one channel of sensation(such as hearing) (seemto/do not seem to) compensate with a slightenhancement in their other sensory abilities.

22. People who become deaf, or who lose anotherchannel of sensation, often experience

inanother ability.

23. (Close-Up) Deaf children raised in a householdwhere sign language is used express higher

and feel more .

Other Important Senses (pp. 224–235)

Objective 17: Describe the sense of touch.

1. The sense of touch is a mixture of at least foursenses: ,

, , and. Other skin sensations, such

as tickle, itch, hot, and wetness, areof the basic ones.

2. The -influence on touch is illustrated by the fact that aself-produced tickle produces less activation inthe than someone else’s tickle.

Objective 18: State the purpose of pain, and describethe biopsychosocial approach to pain.

3. People born without the ability to feel pain maybe unaware of experiencing severe

. People with illness-related experience extreme sensitivi-

ty to things others find only mildly painful.

4. Pain is a property of the as well as of the and our

.

5. A sensation of pain in an amputated leg isreferred to as a

sensation. Another exampleis , experienced by peoplewho have a ringing-in-the-ears sensation.

If you do not know the meaning of any of thefollowing words, phrases, or expressions in thecontext in which they appear in the text, referto pages 155–156 for an explanation: we yearnto touch—to kiss, to stroke, to snuggle; Rubbing thearea around your stubbed toe; Sometimes the painin sprain is mainly in the brain; firewalking, . . .putting his feet where his mouth was; A well-trained nurse may distract needle-shy patients bychatting with them; there is more to taste thanmeets the tongue; bathing your nostrils in a streamof scent-laden molecules; Words more readily por-tray the sound of coffee brewing than its aroma; bio-logical gyroscopes.

6. Pain-producing brain activity may be triggeredwith or without

.

7. The pain system (is/is not)triggered by one specific type of physical energy.The body (does/does not)have specialized receptor cells for pain.

8. Melzack and Wall have proposed a theory of paincalled the -

theory, which proposes thatthere is a neurological inthe that blocks pain signals or lets them through. Itmay be opened by activation of

(small/large) nerve fibersand closed by activation of (small/large) fibers or by information from the

.

9. Individual differences in perceiving pain are anexample of influences onpain. Such influences demonstrate that pain is notmerely a phenomenon, asproposed centuries ago by .Rather, pain is created by the .

List some pain control techniques used in the Lamazemethod of prepared childbirth and in other healthcare situations.

Objective 19: Describe the sense of taste, and explainthe principle of sensory interaction.

10. The basic taste sensations are ,, , , and a meaty taste called.

11. Taste, which is a sense, isenabled by the 200 or more

on thetop and sides of the tongue. Each contains a

that catches food chemicals.

12. Taste receptors reproduce themselves every. As

we age, the number of taste buds (increases/decreases/remains

unchanged) and our taste sensitivity (increases/decreases/remains

unchanged). Taste is also affected byand by

use.

13. When the sense of smell is blocked, as when wehave a cold, foods do not taste the same; thisillustrates the principle of

. The effect occurs when we aspeaker saying one syllable while

another.

Objective 20: Describe the sense of smell, and explainwhy specific odors so easily trigger memories.

14. Like taste, smell, or , is asense. Unlike light, an odor(can/cannot) be separated

into more elemental odors.

15. The ability to identify scents peaks inand

declines thereafter.

16. The attractiveness of smells depends on associations.

17. Odors are able to evoke memories and feelingsbecause there is a direct link between the brainarea that gets information from the nose and theancient centers associatedwith memory and emotion.

Objective 21: Distinguish between kinesthesis andthe vestibular sense.

18. The system for sensing the position and move-ment of body parts is called

. The receptors for this senseare located in the ,

, and of the body.

19. The sense that monitors the position and move-ment of the head (and thus the body) is the

.

Other Important Senses 135

The receptors for this sense are located in the andof the

inner ear.

PROGRESS TEST 1

Multiple-Choice Questions

Circle your answers to the following questions andcheck them with the answers beginning on page 146.If your answer is incorrect, read the explanation forwhy it is correct and then consult the appropriatepages of the text (in parentheses following the correctanswer).

1. Which of the following is true?a. The absolute threshold for any stimulus is a

constant.b. The absolute threshold for any stimulus varies

somewhat.c. The absolute threshold is defined as the mini-

mum amount of stimulation necessary for astimulus to be detected 75 percent of the time.

d. The absolute threshold is defined as the mini-mum amount of stimulation necessary for astimulus to be detected 60 percent of the time.

2. Nearsightedness is a condition in which the:a. lens has become inflexible.b. lens is too thin.c. image falls behind the retina.d. image falls in front of the retina.

3. If you can just notice the difference between 10-and 11-pound weights, which of the followingweights could you differentiate from a 100-poundweight?a. 101-pound weightb. 105-pound weightc. 110-pound weightd. There is no basis for prediction.

4. A decrease in sensory responsiveness accompa-nying an unchanging stimulus is called:a. sensory fatigue. b. accommodation. c. sensory adaptation.d. sensory interaction.

5. The size of the pupil is controlled by the:a. lens. c. cornea.b. retina. d. iris.

6. The process by which the lens changes its curva-ture is:a. accommodation. c. feature detection.b. sensory adaptation. d. transduction.

7. The receptor of the eye that functions best in dimlight is the:a. fovea. c. bipolar cell.b. cone d. rod.

8. The Young-Helmholtz theory proposes that:a. there are three different types of color-

sensitive cones.b. retinal cells are excited by one color and inhib-

ited by its complementary color.c. there are four different types of cones.d. rod, not cone, vision accounts for our ability

to detect fine visual detail.

9. Frequency is to pitch as is to.

a. wavelength; loudnessb. amplitude; loudnessc. wavelength; intensityd. amplitude; intensity

10. Our experience of pain when we are injureddepends on:a. our biological make-up and the type of injury

we have sustained.b. how well medical personnel deal with our

injury.c. our physiology, experiences and attention,

and our surrounding culture.b. what our cultural allows us to express in

terms of feelings of pain.

11. The place theory of pitch perception cannot ac-count for how we hear:a. low-pitched sounds.b. middle-pitched sounds.c. high-pitched sounds.d. chords (three or more pitches simultaneous-

ly).

12. The hearing losses that occur with age are espe-cially pronounced for:a. low-pitched sounds.b. middle-pitched sounds.c. high-pitched sounds.d. chords.


13. According to the gate-control theory, a way toalleviate chronic pain would be to stimulate the

nerve fibers that thespinal gate.a. small; open c. large; openb. small; close d. large; close

14. The transduction of light energy into nerve im-pulses takes place in the:a. iris. c. lens.b. retina. d. optic nerve.

15. The brain breaks vision into separate dimensionssuch as color, depth, movement, and form, andworks on each aspect simultaneously. This iscalled:a. feature detection.b. parallel processing.c. accommodation.d. opponent processing.

16. Kinesthesis involves:a. the bones of the middle ear.b. information from the muscles, tendons, and

joints.c. membranes within the cochlea.d. the body’s sense of balance.

17. One light may appear reddish and another green-ish if they differ in:a. wavelength. c. opponent processes.b. amplitude. d. brightness.

18. Which of the following explains why a rose ap-pears equally red in bright and dim light?a. the Young-Helmholtz theoryb. the opponent-process theoryc. feature detectiond. color constancy

19. Which of the following is an example of sensoryadaptation?a. finding the cold water of a swimming pool

warmer after you have been in it for a whileb. developing an increased sensitivity to salt the

more you use it in foodsc. becoming very irritated at the continuing

sound of a dripping faucetd. All of the above are examples.

20. Most color-deficient people will probably:a. lack functioning red- or green-sensitive cones.b. see the world in only black and white.c. also suffer from poor vision.d. have above-average vision to compensate for

the deficit.

Progress Test 1 137

Matching Items

Match each of the structures with its function ordescription.

Structures or Conditions

1. lens2. iris3. pupil4. rods5. cones6. middle ear7. inner ear8. large nerve fiber9. small nerve fiber

10. semicircular canals11. sensors in joints12. acuity13. farsightedness14. nearsightedness

Functions or Descriptions

a. amplifies soundsb. closes pain gatec. vestibular sensed. controls pupile. accommodationf. eyeball is too shortg. opens pain gateh. admits lighti. eyeball is too longj. vision in dim light

k. transduction of soundl. sharpness of vision

m. kinesthesisn. color vision

PROGRESS TEST 2

Progress Test 2 should be completed during a finalchapter review. Answer the following questions afteryou thoroughly understand the correct answers forthe section reviews and Progress Test 1.


1. Which of the following is not one of the basictastes?a. sweet c. umamib. salty d. bland

2. Of the four distinct skin senses, the only one thathas definable receptors is:a. warmth. c. pressure.b. cold. d. pain.

3. The process by which sensory information is con-verted into neural energy is:a. sensory adaptation. c. signal detection.b. feature detection. d. transduction.

4. The receptors for taste are located in the:a. taste buds. c. fovea.b. cochlea. d. cortex.

5. The inner ear contains receptors for:a. audition and kinesthesis.b. kinesthesis and the vestibular sense.c. audition and the vestibular sense.d. audition, kinesthesis, and the vestibular sense.

6. According to the opponent-process theory:a. there are three types of color-sensitive cones.b. the process of color vision begins in the cortex.c. neurons involved in color vision are stimulat-

ed by one color’s wavelength and inhibited byanother’s.

d. all of the above are true.

7. Nerve deafness is caused by:a. wax buildup in the outer ear.b. damage to the eardrum.c. blockage in the middle ear because of

infection.d. damage to the cochlea.

8. What enables you to feel yourself wiggling yourtoes even with your eyes closed?a. vestibular sense b. sense of kinesthesisc. the skin sensesd. sensory interaction

9. The frequency theory of hearing is better thanplace theory at explaining our sensation of:a. the lowest pitches.b. pitches of intermediate range.c. the highest pitches.d. all of the above.

10. Hubel and Wiesel discovered feature detectors inthe visual:a. fovea. c. iris.b. optic nerve. d. cortex.

11. Weber’s law states that: a. the absolute threshold for any stimulus is a

constant.b. the jnd for any stimulus is a constant.c. the absolute threshold for any stimulus is a

constant proportion.d. the jnd for any stimulus is a constant propor-

tion.

12. The principle that one sense may influence an-other is:a. transduction. c. Weber’s law.b. sensory adaptation. d. sensory interaction.

13. Which of the following is the correct order of thestructures through which light passes after enter-ing the eye?a. lens, pupil, cornea, retinab. pupil, cornea, lens, retinac. pupil, lens, cornea, retinad. cornea, pupil, lens, retina

14. In the opponent-process theory, the three pairs ofprocesses are:a. red-green, blue-yellow, black-white.b. red-blue, green-yellow, black-white.c. red-yellow, blue-green, black-white.d. dependent upon the individual’s

experience.

15. Wavelength is to as is to brightness.a. hue; intensityb. intensity; huec. frequency; amplituded. brightness; hue


16. Concerning the evidence for subliminal stimula-tion, which of the following is the best answer?a. The brain processes some information without

our awareness.b. Stimuli too weak to cross our thresholds for

awareness may trigger a response in our sensereceptors.

c. Because the “absolute” threshold is a statisti-cal average, we are able to detect weaker stim-uli some of the time.

d. All of the above are true.

17. Which of the following is the most accurate de-scription of how we process color?a. Throughout the visual system, color process-

ing is divided into separate red, green, andblue systems.

b. Red-green, blue-yellow, and black-white op-ponent processes operate throughout the visu-al system.

c. Color processing occurs in two stages: (1) athree-color system in the retina and (2) oppo-nent-process cells en route to the visual cortex.

d. Color processing occurs in two stages: (1) anopponent-process system in the retina and (2)a three-color system en route to the visualcortex.

18. Which of the following is the most accurateexplanation of how we discriminate pitch?a. For all audible frequencies, pitch is coded

according to the place of maximum vibrationon the cochlea’s basilar membrane.

b. For all audible frequencies, the rate of neuralactivity in the auditory nerve matches the fre-quency of the sound wave.

c. For very high frequencies, pitch is coded ac-cording to place of vibration on the basilarmembrane; for lower pitches, the rate of neur-al activity in the auditory nerve matches thesound’s frequency.

d. For very high frequencies, the rate of neuralactivity in the auditory nerve matches the fre-quency of the sound wave; for lower frequen-cies, pitch is coded according to the place ofvibration on the basilar membrane.

19. One reason that your ability to detect fine visualdetails is greatest when scenes are focused on thefovea of your retina is that:a. there are more feature detectors in the fovea

than in the peripheral regions of the retina.b. cones in the fovea are nearer to the optic nerve

than those in peripheral regions of the retina.

c. many rods, which are clustered in the fovea,have individual bipolar cells to relay theirinformation to the cortex.

d. many cones, which are clustered in the fovea,have individual bipolar cells to relay their in-formation to the cortex.

20. Given normal sensory ability, a person standingatop a mountain on a dark, clear night can see acandle flame atop a mountain 30 miles away. Thisis a description of vision’s:a. difference threshold. c. absolute threshold.b. jnd. d. signal detection.

PSYCHOLOGY APPLIED

Answer these questions the day before an exam as afinal check on your understanding of the chapter’sterms and concepts.


1. In shopping for a new stereo, you discover thatyou cannot differentiate between the sounds ofmodels X and Y. The difference between X and Yis below your:a. absolute threshold. c. receptor threshold.b. signal detection. d. difference threshold.

2. In order to maximize your sensitivity to fine visu-al detail you should:a. stare off to one side of the object you are

attempting to see.b. close one eye.c. decrease the intensity of the light falling upon

the object.d. stare directly at the object.

3. The phantom limb sensation indicates that:a. pain is a purely sensory phenomenon.b. the central nervous system plays only a minor

role in the experience of pain.c. pain involves the brain’s interpretation of

neural activity.d. all of the above are true.

Psychology Applied 139

4. While competing in the Olympic trials, marathon-er Kirsten O’Brien suffered a stress fracture in herleft leg. That she did not experience significantpain until the race was over is probably attribut-able to the fact that during the race:a. the pain gate in her spinal cord was closed by

information coming from her brain.b. her body’s production of endorphins de-

creased.c. an increase in the activity of small pain fibers

closed the pain gate.d. a decrease in the activity of large pain fibers

closed the pain gate.

5. Which of the following is an example of sensoryinteraction?a. finding that despite its delicious aroma, a

weird-looking meal tastes awfulb. finding that food tastes bland when you have

a bad coldc. finding it difficult to maintain your balance

when you have an ear infectiond. All of the above are examples.

6. In comparing the human eye to a camera, the filmwould be located in the eye’s: a. pupil. c. cornea.b. lens. d. retina.

7. Sensation is to as perception is to.

a. recognizing a stimulus; interpreting a stimulus

b. detecting a stimulus; recognizing a stimulusc. interpreting a stimulus; detecting a stimulusd. seeing; hearing

8. I am a cell in the thalamus that is excited by redand inhibited by green. I am a(n):a. feature detector. c. bipolar cell.b. cone. d. opponent-process cell.

9. Which of the following correctly lists the order ofstructures through which sound travels after en-tering the ear?a. auditory canal, eardrum, middle ear, cochleab. eardrum, auditory canal, middle ear, cochleac. eardrum, middle ear, cochlea, auditory canald. cochlea, eardrum, middle ear, auditory canal

10. Dr. Frankenstein has forgotten to give his mon-ster an important part; as a result, the monstercannot transduce sound. Dr. Frankenstein omit-ted the:a. eardrum. c. semicircular canals.b. middle ear. d. basilar membrane.

11. Seventy-five-year-old Claude has difficulty hear-ing high-pitched sounds. Most likely his hearingproblem involves:a. his eardrum.b. his auditory canal.c. the bones of his middle ear.d. the hair cells of his inner ear.

12. Which of the following is true of cones?a. Cones enable color vision.b. Cones are highly concentrated in the foveal

region of the retina.c. Cones have a higher absolute threshold for

brightness than rods.d. All of the above are true.

13. Assuming that the visual systems of humans andother mammals function similarly, you wouldexpect that the retina of a nocturnal mammal (oneactive only at night) would contain:a. mostly cones.b. mostly rods.c. an equal number of rods and cones.d. more bipolar cells than an animal active only

during the day.

14. As the football game continued into the night,LeVar noticed that he was having difficulty dis-tinguishing the colors of the players’ uniforms.This is because the , which enable colorvision, have a absolute threshold forbrightness than the available light intensity.a. rods; higher c. rods; lowerb. cones; higher d. cones; lower

15. After staring at a very intense red stimulus for afew minutes, Carrie shifted her gaze to a beigewall and “saw” the color . Carrie’s experi-ence provides support for the theory.a. green; trichromaticb. blue; opponent-processc. green; opponent-processd. blue; trichromatic


16. Elderly Mrs. Martinez finds that she must spiceher food heavily or she cannot taste it. Unfor-tunately, her son often finds her cooking inediblebecause it is so spicy. What is the likely explana-tion for their taste differences?a. Women have higher taste thresholds than

men.b. Men have higher taste thresholds than wo-

men.c. Being elderly, Mrs. Martinez probably has

fewer taste buds than her son.d. All of the above are likely explanations.

17. When admiring the texture of a piece of fabric,Calvin usually runs his fingertips over the cloth’ssurface. He does this because:a. if the cloth were held motionless, sensory

adaptation to its feel would quickly occur.b. the sense of touch does not adapt.c. a relatively small amount of brain tissue is

devoted to processing touch from the finger-tips.

d. of all the above reasons.

18. Superman’s eyes used , while hisbrain used . a. perception; sensationb. top-down processing; bottom-up processingc. bottom-up processing; top-down processingd. sensory adaptation; subliminal perception

19. How does pain differ from other senses?a. It has no special receptors.b. It has no single stimulus.c. It is influenced by both physical and psycho-

logical phenomena.d. All the above are true.

20. Tamiko hates the bitter taste of her cough syrup.Which of the following would she find most help-ful in minimizing the syrup’s bad taste?a. tasting something very sweet before taking

the cough syrupb. keeping the syrup in her mouth for several

seconds before swallowing itc. holding her nose while taking the cough

syrupd. gulping the cough syrup so that it misses her

tongue

Essay Question

A dancer in a chorus line uses many sensory cueswhen performing. Discuss three senses that dancersrely on and explain why each is important. (Use thespace below to list the points you want to make, andorganize them. Then write the essay on a separatesheet of paper.)

Psychology Applied 141

Summing Up

Use the diagrams to identify the parts of the eye andear, then list them in the order in which they con-tribute to vision and hearing. Also, briefly explain therole of each structure.

The Eye

1.

2.

3.

4.

5.

6.

7.


The Ear1.

2.

3.

4.

5.

6.

7.

8.

Key Terms

Writing Definitions

Using your own words, on a piece of paper write abrief definition or explanation of each of the follow-ing terms.

1. sensation

2. perception

3. bottom-up processing

4. top-down processing

5. psychophysics

6. absolute threshold

7. signal detection theory

8. subliminal

9. priming

10. difference threshold

11. Weber’s law

12. sensory adaptation

13. transduction

14. wavelength and hue

15. intensity

16. pupil

17. iris

18. lens

19. accommodation

20. retina

21. acuity

22. nearsightedness

23. farsightedness

24. rods and cones

25. optic nerve

26. blind spot

27. fovea

28. feature detectors

29. parallel processing

30. Young-Helmholtz trichromatic (three-color)theory

31. opponent-process theory

32. color constancy

33. audition

34. pitch and frequency

35. middle ear

36. cochlea

37. inner ear

38. place theory

39. frequency theory

40. conduction hearing loss

41. sensorineural hearing loss

42. cochlear implant

43. gate-control theory

44. sensory interaction

45. kinesthesis

46. vestibular sense

Key Terms 143

Cross-Check

As you learned in the Prologue,reviewing and overlearning ofmaterial are important to thelearning process. After youhave written the definitions ofthe key terms in this chapter,you should complete the cross-word puzzle to ensure that youcan reverse the process—recognize the term, given thedefinition.

ACROSS

1. The retina’s point of centralfocus.

7. Types of fibers that closethe “pain gate.”

12. Nerve that carries visualinformation to the brain.

13. Aspect of light and sounddetermined by the ampli-tude of energy waves.

14. Unit of measurement forelectromagnetic energy.

15. The perceptual experienceof color.

16. Membrane that lies at theend of the auditory canal.

17. Term for the color seen after staring at its oppo-nent for a while.

19. Physical dimension of light and sound that deter-mines brightness and loudness, respectively.

21. Type of deafness that results from damage in themechanics of the outer or middle ear.

22. Membrane “window” at the entrance to the ear’scochlea.

28. Adjustable opening in the eye through whichlight enters.

29. Sense of hearing.30. Transparent protective membrane through which

light enters the eye.31. Inner surface of the eye that contains the rods and

cones.

DOWN

1. Theory of hearing that the rate of auditory nerveimpulses matches the frequency of tones,enabling us to sense pitch.

2. Type of vision caused by a shorter-than-normaleyeball.

3. Energy spectrum that contains visible light.4. Type of brain cell discovered by Hubel and

Wiesel.5. The basis of a “bionic ear.”

6. -down processing is information processingguided by higher-level mental processes.

8. Sense of the position and movement of bodyparts.

9. Ability of some brain-damaged patients torespond to something that is not consciously per-ceived.

10. Study of the relationship between the physicalcharacteristics of stimuli and our psychologicalexperience of them.

11. Perception of color is strongly influenced by theobject’s .

18. Region of the retina where the optic nerve leavesthe eye.

20. Part of the eye that changes shape to focus imageson the retina.

23. Sharpness of vision.24. Region of the ear that contains the hammer, anvil,

and stirrup.25. Region of the ear that contains the cochlea.26. Theory that the region of maximum vibration

along the basilar membrane is the basis of pitchdiscrimination.

27. Visual receptors that are concentrated in theperiphery of the retina.


4

12

3

7

2

5

13

8 9 10

15

6

22 23

28

24

31

14

1

11

16

17

19 20

21

18

29

2726

30

25

ANSWERS

Chapter Review

Introduction

1. sensation; perception2. bottom-up processing; top-down processing3. prosopagnosia

Sensing the World: Some Basic Principles

1. psychophysics2. absolute threshold; 503. signal detection; psychological4. subliminal5. conscious6. prime; priming effect; automatically7. difference threshold; just noticeable difference 8. Weber’s law; stimulus9. sensory adaptation

10. informativeAlthough sensory adaptation reduces our sensitivity,it enables us to focus our attention on informativechanges in the environment without being distractedby the uninformative, constant stimulation that bom-bards our senses.

Vision

1. neural; transduction2. electromagnetic3. wavelength; hue4. intensity; amplitude; brightness5. cornea; pupil; iris6. lens; retina7. accommodation; acuity8. distant; in front of; nearby; distant; nearby; in

back of; distant; nearby9. rods; cones

10. bipolar; ganglion; optic nerve; brain11. blind spot12. fovea; peripheral; bipolar13. cones; rods14. sensitive; 2015. abstract; thalamus; visual cortex; feature detectors16. temporal; gaze; head angle; posture; body move-

ment; perceives17. simultaneously; parallel processing; blindsight

18. integration; gamma; similar19. reflects (rejects); construction

20. sex-linked

21. Young-Helmholtz trichromatic; red; green; blue;additive; subtractive

22. opponent; afterimage

23. opponent-process; red; green; yellow; blue; black;white

In the first stage of color processing, the retina’s red,green, and blue cones respond in varying degrees todifferent color stimuli, as suggested by the three-colortheory. The resulting signals are then processed in thethalamus by red-green, blue-yellow, and black-whiteopponent-process cells, which are stimulated by onewavelength and inhibited by its opponent.

24. context25. color constancy26. reflected; surrounding objects

Hearing

1. audition; air molecules2. loudness3. frequency4. decibels; 05. outer; middle; inner6. eardrum7. hammer; anvil; stirrup8. cochlea; oval window; basilar membrane; hair

cells; thalamus; temporal; number9. less; stress; high blood pressure; anxiety; feelings

of helplessness; unanticipated; uncontrollable10. place; low11. frequency; high; 100012. volley13. speed (timing); loudness14. harder15. parallel processing16. conduction hearing loss17. sensorineural; aging18. stimulate19. cochlear implant20. Deaf culture; children; speak; disability 21. is; with; have; seem to22. sensory compensation23. self-esteem; accepted

Answers 145

Other Important Senses

1. pressure; warmth; cold; pain; variations2. top-down; somatosensory cortex3. injury; hyperalgesia4. senses; brain; expectations5. phantom limb; tinnitus6. sensory input7. is not; does not8. gate-control; gate; spinal cord; small; large;

brain9. social; physical; René Descartes; brain

The Lamaze method of prepared childbirth combinesseveral pain control techniques, including distraction,deep breathing and muscle relaxation, and counter-stimulation through gentle massage. Similarly, forburn victims, distraction during painful wound carecan be created by immersion in a computer-generated3-D world.10. sweet; sour; salty; bitter; umami (meat)11. chemical; taste buds; pore12. week or two; decreases; decreases; smoking;

alcohol13. sensory interaction; McGurk; see; hearing14. olfaction; chemical; cannot15. early adulthood16. learned17. limbic18. kinesthesis; muscles; tendons; joints19. vestibular sense; semicircular canals; vestibular

sacs

Progress Test 1


1. b. is the answer. Psychological factors can affectthe absolute threshold for a stimulus. (pp.199–200)a. The absolute threshold for detecting a stimulusdepends not only on the strength of the stimulusbut also on psychological factors such as experi-ence, expectations, motivation, and fatigue. Thus,the threshold cannot be a constant.c. & d. The absolute threshold is defined as theminimum stimulus that is detected 50 percent ofthe time.

2. d. is the answer. In nearsightedness, objects con-verge in front of the retina; one cause of this is aneyeball longer than normal in relation to the lens.(p. 206)

a. Inflexibility of the lens may cause the emer-gence of farsightedness as we get older.b. Thinness of the lens is unrelated to near- or far-sightedness.c. A shorter-than-normal eyeball is related to far-sightedness.

3. c. is the answer. According to Weber’s law, thedifference threshold is a constant proportion ofthe stimulus. There is a 10 percent differencebetween 10 and 11 pounds; since the differencethreshold is a constant proportion, the weightclosest to 100 pounds that can nonetheless be dif-ferentiated from it is 110 pounds (or 100 poundsplus 10 percent). (p. 201)

4. c. is the answer. (p. 202)a. “Sensory fatigue” is not a term in psychology.b. Accommodation refers to an adaptive changein shape by the lens of the eye.d. Sensory interaction is the principle that onesense may influence another.

5. d. is the answer. (p. 205)a. The lens lies behind the pupil and focuses lighton the retina.b. The retina is the inner surface of the eyeballand contains the rods and cones.c. The cornea lies in front of the pupil and is thefirst structure that light passes through as itenters the eye.

6. a. is the answer. (p. 205)b. Sensory adaptation is our diminishing sensitiv-ity to an unchanging stimulus.c. Feature detection is the process by which neur-al cells in the brain respond to specific visual fea-tures.d. Transduction refers to the conversion of anenvironmental stimulus, such as light, into aneural impulse by a receptor—a rod or a cone.

7. d. is the answer. (p. 208)a. The fovea is not a receptor; it is a region of theretina that contains only cones.b. Cones have a higher threshold for brightnessthan rods and therefore do not function as well indim light.c. Bipolar cells are not receptors; they are neuronsin the retina that link rods and cones with gan-glion cells, which make up the optic nerve.

8. a. is the answer. The Young-Helmholtz theoryproposes that there are red-, green-, and blue-sensitive cones. (p. 212)b. This answer describes Hering’s opponent-process theory.c. The Young-Helmholtz theory proposes thatthere are three types of cones, not four.


d. The Young-Helmholtz theory concerns onlycolor vision, not the detection of visual detail.

9. b. is the answer. Just as wave frequency deter-mines pitch, so wave amplitude determines loud-ness. (p. 216)a. Amplitude is the physical basis of loudness;wavelength determines frequency and therebypitch.c. & d. Wavelength, amplitude, and intensity arephysical aspects of light and sound. Because thequestion is based on a relationship between aphysical property (frequency) of a stimulus andits psychological attribute (pitch), these answersare incorrect.

10. c. is the answer. The biopsychosocial approachtells us that our experience of pain depends onbiological, psychological, and social-cultural fac-tors.. (p. 226)

11. a. is the answer. (p. 219)b. & c. Although the localization of low-pitchedsounds along the basilar membrane is poor, thatfor sounds of middle and, especially, high pitch isgood. Therefore, place theory accounts well forhigh-pitched sounds and, together with fre-quency theory, can account for middle-pitchedsounds.d. As long as the notes of a chord are within therange of responsiveness of the basilar membrane,chord perception can be accounted for by placetheory.

12. c. is the answer. (p. 220)d. Chord perception, except for chords comprisedexclusively of high-frequency notes, shows noage-dependent decline.

13. d. is the answer. The small fibers conduct mostpain signals; the large fibers conduct most othersensory signals from the skin. The gate eitherallows pain signals to pass on to the brain orblocks them from passing. When the large fibersare stimulated, the pain gate is closed and othersensations are felt in place of pain. (p. 227)

14. b. is the answer. (pp. 206–207)a. The iris controls the diameter of the pupil.c. The lens accommodates its shape to focusimages on the retina.d. The optic nerve carries nerve impulses fromthe retina to the visual cortex.

15. b. is the answer. (p. 210)a. Feature detection is the process by which nervecells in the brain respond to specific visual fea-tures of a stimulus, such as movement or shape.c. Accommodation is the process by which thelens changes its curvature to focus images on theretina.

d. The opponent-process theory suggests thatcolor vision depends on the response of braincells to red-green, yellow-blue, and black-whiteopposing colors.

16. b. is the answer. Kinesthesis, or the sense of theposition and movement of body parts, is based oninformation from the muscles, tendons, andjoints. (p. 233)a. & c. The ear plays no role in kinesthesis.d. Equilibrium, or the sense of balance, is not in-volved in kinesthesis but is, rather, a companionsense.

17. a. is the answer. Wavelength determines hue, orcolor. (pp. 204–205)b. & d. The amplitude of light determines itsbrightness.c. Opponent processes are neural systems in-volved in color vision, not properties of light.

18. d. is the answer. Color constancy is the percep-tion that a familiar object has consistent color,even if changing illumination alters the wave-lengths reflected by that object. (pp. 213–214)a. & b. These theories explain how the visual sys-tem detects color; they do not explain why colorsdo not seem to change when lighting does.c. Feature detection explains how the brain recog-nizes visual images by analyzing their distinctivefeatures of shape, movement, and angle.

19. a. is the answer. Sensory adaptation means adiminishing sensitivity to an unchanging stimu-lus. Only the adjustment to cold water involves adecrease in sensitivity; the other examples in-volve an increase. (p. 202)

20. a. is the answer. Thus, they have difficulty dis-criminating these two colors. (p. 212)b. Those who are color deficient are usually not“color blind” in a literal sense. Instead, they areunable to distinguish certain hues, such as redfrom green.c. Failure to distinguish red and green is separatefrom, and does not usually affect, general visualability.d. Color deficiency does not enhance vision. Adeficit in one sense often is compensated for byoverdevelopment of another sense—for example,hearing in blind people.

Matching Items

1. e (p. 205) 6. a (p. 217) 11. m (p. 233)2. d (p. 205) 7. k (p. 217) 12. l (p. 206)3. h (p. 205) 8. b (p. 227) 13. f (p. 206)4. j (p. 206) 9. g (p. 227) 14. i (p. 206)5. n (p. 206) 10. c (p. 234)

Answers 147

Progress Test 2


1. d. is the answer. (p. 229)2. c. is the answer. Researchers have identified re-

ceptors for pressure but have been unable to doso for the other skin senses. (p. 225)

3. d. is the answer. (p. 204)a. Sensory adaptation refers to the diminishedsensitivity that occurs with unchanging stimula-tion. b. Feature detection refers to the process bywhich nerve cells in the brain respond to specificaspects of visual stimuli, such as movement orshape.c. Signal detection is a task in which the observermust judge whether a faint signal is present.

4. a. is the answer. (p. 230)b. The cochlea contains receptors for hearing.c. The fovea contains receptors for vision (thecones).d. The cortex is the outer layer of the brain, whereinformation detected by the receptors is pro-cessed.

5. c. is the answer. The inner ear contains the recep-tors for audition (hearing) and the vestibularsense; those for kinesthesis are located in themuscles, tendons, and joints. (pp. 217, 234)

6. c. is the answer. After leaving the receptor cells,visual information is analyzed in terms of pairs ofopponent colors; neurons stimulated by onemember of a pair are inhibited by the other. (p.213)a. The idea that there are three types of color-sensitive cones is the basis of the Young-Helmholtz three-color theory.b. According to the opponent-process theory, andall other theories of color vision, the process ofcolor vision begins in the retina.

7. d. is the answer. Sensorineural hearing loss iscaused by destruction of neural tissue as a resultof problems with the cochlea’s receptors or theauditory nerve. (p. 220)a. & c. Wax buildup and blockage because ofinfection are temporary states; sensorineuralhearing loss is permanent. Moreover, sensori-neural hearing loss involves the inner ear, ratherthan the outer or middle ear.b. Damage to the eardrum impairs the mechani-cal system that conducts sound waves; it couldtherefore cause conduction hearing loss, not sen-sorineural hearing loss.

8. b. is the answer. Kinesthesis, the sense of move-ment of body parts, would enable you to feelyour toes wiggling. (p. 233)a. The vestibular sense is concerned with move-ment and position, or balance, of the whole body,not of its parts.c. The skin, or tactile, senses are pressure, pain,warmth, and cold; they have nothing to do withmovement of body parts.d. Sensory interaction, the principle that the sens-es influence each other, does not play a role inthis example, which involves only the sense ofkinesthesis.

9. a. is the answer. Frequency theory best explainsthe lowest pitches. Place theory best explains thehighest pitches, and some combination of the twotheories probably accounts for our sensation ofintermediate-range pitches. (p. 219)

10. d. is the answer. Feature detectors are corticalneurons and hence are located in the visual cor-tex. (p. 209)a. The fovea contains cones.b. The optic nerve contains neurons that relaynerve impulses from the retina to higher centersin the visual system.c. The iris is simply a ring of muscle tissue, whichcontrols the diameter of the pupil.

11. d. is the answer. Weber’s law concerns differencethresholds (jnd’s), not absolute thresholds, andstates that these are constant proportions of thestimuli, not that they remain constant. (p. 202)

12. d. is the answer. (p. 230)a. Transduction is the process by which stimulusenergy is converted into nerve impulses.b. Sensory adaptation is diminished sensitivity tounchanging stimulation.c. Weber’s law states that the jnd is a constantproportion of a stimulus.

13. d. is the answer. (p. 205)14. a. is the answer. (p. 213)15. a. is the answer. Wavelength determines hue, and

intensity determines brightness. (pp. 204–205)16. d. is the answer. (pp. 200–201)17. c. is the answer. (p. 211)

a. This answer is incorrect because separate red,green, and blue systems operate only in the retina. b. This answer is incorrect because opponent-process systems operate en route to the brain,after visual processing in the receptors is completed.d. This answer is incorrect because it reverses thecorrect order of the two stages of processing.


18. c. is the answer. (p. 219)a. This answer describes how pitch is sensed inthe case of high-pitched, but not low-pitched,sounds. b. This answer describes how pitch is sensed inthe case of low-pitched, but not high-pitched,sounds.d. This answer is incorrect because it reverses therange of frequencies.

19. d. is the answer. (p. 207)a. Feature detectors are nerve cells located in thevisual cortex, not in the fovea of the retina.b. The proximity of rods and cones to the opticnerve does not influence their ability to resolvefine details.c. Rods are concentrated in the peripheral regionsof the retina, not in the fovea; moreover, severalrods share a single bipolar cell.

20. c. is the answer. The absolute threshold is theminimum stimulation needed to detect a stimu-lus. (p. 199)a. & b. The difference threshold, which is alsoknown as the jnd, is the minimum differencebetween two stimuli that a person can detect. Inthis example, there is only one stimulus—thesight of the flame.d. Signal detection is a research task, not a senso-ry phenomenon.

Psychology Applied


1. d. is the answer. (p. 201)a. The absolute threshold refers to whether a sin-gle stimulus can be detected, not to whether twostimuli can be differentiated.b. Signal detection is a task in which one mustdetermine whether or not a faint stimulus is present.c. A receptor threshold is a minimum amount ofenergy that will elicit a neural impulse in a recep-tor cell.

2. d. is the answer. Greater sensitivity to fine visualdetail is associated with the cones, which havetheir own bipolar cells to relay information to thecortex. The cones are concentrated in the fovea,the retina’s point of central focus. For this reason,staring directly at an object maximizes sensitivityto fine detail. (p. 207)a. If you stare off to one side, the image falls ontoperipheral regions of the retina, where rods areconcentrated and sensitivity to fine visual detailis poor.

b. Sensitivity to detail is not directly influencedby whether one or both eyes are stimulated.c. Decreasing the intensity of light would onlyimpair the functioning of the cones, which aresensitive to visual detail but have a high thresh-old for light intensity.

3. c. is the answer. Since pain is felt in the limb thatdoes not exist, the pain is simply the brain’s(mis)interpretation of neural activity. (p. 227)a. If pain were a purely sensory phenomenon,phantom limb pain would not occur, since thereceptors are no longer present.b. That pain is experienced when a limb is miss-ing indicates that the central nervous system,especially the brain, is where pain is sensed.

4. a. is the answer. (p. 227)b. Since endorphins relieve pain, a decrease intheir production would have made Kirsten morelikely to experience pain. Moreover, because en-dorphins are released in response to pain, theirproduction probably would have increased.c. Neural activity in small fibers tends to open thepain gate.d. An increase in large-fiber activity would tend toclose the pain gate.

5. d. is the answer. Each of these is an example ofthe interaction of two senses—vision and taste inthe case of a., taste and smell in the case of b., andhearing and the vestibular sense in the case of c.(p. 230)

6. d. is the answer. Just as light strikes the film of acamera, visual images entering the eye are pro-jected onto the retina. (p. 206)a. The pupil would be analogous to the apertureof a camera, since both control the amount oflight permitted to enter.b. The lens of the eye performs a focusing func-tion similar to the lens of the camera.c. The cornea would be analogous to a camera’slens cap in that both protect delicate inner struc-tures.

7. b. is the answer. (p. 197)a. Both recognition and interpretation are exam-ples of perception.c. This answer would have been correct if thequestion had read, “Perception is to sensation as

is to .”d. Sensation and perception are important pro-cesses in both hearing and seeing.

8. d. is the answer. (p. 213)a. Feature detectors are located in the visual cor-tex and respond to features such as movement,shape, and angle.b. & c. Cones and bipolar cells are located in the

Answers 149

retina. Moreover, neither are excited by some col-ors and inhibited by others.

9. a. is the answer. (p. 217)

10. d. is the answer. The hair cells, which transducesound energy, are located on the basilar mem-brane. (p. 207)a. & b. The eardrum and bones of the middle earmerely conduct sound waves to the inner ear,where they are transduced.c. The semicircular canals are involved in thevestibular sense, not hearing.

11. d. is the answer. Hearing losses that result fromaging are greatest in the higher frequencies andinvolve damage to the hair cells on the basilarmembrane of the cochlea. (p. 220)a., b., & c. Damage to the eardrum, auditorycanal, or bones of the middle ear would probablycause conduction hearing loss and reduced sensi-tivity to sounds of all frequencies.

12. d. is the answer. (p. 207)

13. b. is the answer. Rods and cones enable vision indim and bright light, respectively. If an animal isactive only at night, it is likely to have more rodsthan cones in its retinas. (p. 208)d. Bipolar cells link both cones and rods to gan-glion cells. There is no reason to expect that anocturnal mammal would have more bipolarcells than a mammal active both during the dayand at night. If anything, because several rodsshare a single bipolar cell, whereas many coneshave their own, a nocturnal animal (with a visualsystem consisting mostly of rods) might be ex-pected to have fewer bipolar cells than an animalactive during the day (with a visual system con-sisting mostly of cones).

14. b. is the answer. (p. 208)a. & c. It is the cones, rather than the rods, thatenable color vision.d. If the cones’ threshold were lower than theavailable light intensity, they would be able tofunction and therefore detect the colors of theplayers’ uniforms.

15. c. is the answer. (p. 213)a. The trichromatic theory cannot account for theexperience of afterimages.b. & d. Afterimages are experienced as the com-plementary color of a stimulus. Green, not blue, isred’s complement.

16. c. is the answer. As people age they lose taste

buds and their taste thresholds increase. For thisreason, Mrs. Martinez needs more concentratedtastes than her son to find food palatable. (p. 230)a. & b. There is no evidence that women and mendiffer in their absolute thresholds for taste.

17. a. is the answer. (pp. 202–203)b. The sense of touch (pressure) adapts veryquickly. c. On the contrary, the extreme sensitivity of thefingertips is due to the relatively large amount ofcortical tissue that processes neural impulsesfrom the fingertips.

18. c. is the answer. (p. 197)19. d. is the answer. (pp. 226–227)20. c. is the answer. Because of the powerful sensory

interaction between taste and smell, eliminatingthe odor of the cough syrup should make its tastemore pleasant. (p. 230)a. If anything, the contrasting tastes might makethe bitter syrup even less palatable.b. If Tamiko keeps the syrup in her mouth forseveral seconds, it will ensure that her taste poresfully “catch” the stimulus, thus intensifying thebitter taste.d. It’s probably impossible to miss the tonguecompletely.

Essay Question

The senses that are most important to dancers arevision, hearing, kinesthesis, and the vestibular sense.Your answer should refer to any three of these sensesand include, at minimum, the following information.

Dancers rely on vision to gauge their body posi-tion relative to other dancers as they perform specificchoreographed movements. Vision also helps dancersassess the audience’s reaction to their performance.Whenever dance is set to music, hearing is necessaryso that the dancers can detect musical cues for certainparts of their routines. Hearing also helps the dancerskeep their movements in time with the music.Kinesthetic receptors in dancers’ muscles, tendons,and joints provide their brains with informationabout the position and movement of body parts todetermine if their hands, arms, legs, and heads are inthe proper positions. Receptors for the vestibularsense located in the dancers’ inner ears send mes-sages to their brains that help them maintain theirbalance and determine the correctness of the positionand movement of their bodies.


Summing Up

The Eye

1. Cornea. Light enters the eye through this trans-parent membrane, which protects the inner struc-tures from the environment.

2. Iris. The colored part of the eye, the iris functionslike the aperture of a camera, controlling the sizeof the pupil to optimize the amount of light thatenters the eye.

3. Pupil. The adjustable opening in the iris, thepupil allows light to enter.

4. Lens. This transparent structure behind the pupilchanges shape to focus images on the retina.

5. Retina. The light-sensitive inner surface of theeye, the retina contains the rods and cones, whichtransduce light energy into neural impulses.

6. Blind spot. The region of the retina where theoptic nerve leaves the eye, the blind spot containsno rods or cones and so there is no vision here.

7. Optic nerve. This bundle of nerve fibers carriesneural impulses from the retina to the brain.

The Ear

1. Outer ear. Hearing begins as sound waves enterthe auditory canal of the outer ear.

2. Auditory canal. Sound waves passing throughthe auditory canal are brought to a point of focusat the eardrum.

3. Eardrum. Lying between the outer and middleear, this membrane vibrates in response to soundwaves.

4. Middle ear. Lying between the outer and innerear, this air-filled chamber contains the hammer,anvil, and stirrup.

5. Hammer, anvil, and stirrup. These tiny bones ofthe middle ear concentrate the eardrum’s vibra-tions on the cochlea’s oval window.

6. Inner ear. This region of the ear contains thecochlea and the semicircular canals, which playan important role in balance.

7. Cochlea. This fluid-filled multichambered struc-ture contains the hair cell receptors that transducesound waves into neural impulses.

8. Auditory nerve. This bundle of fibers carriesnerve impulses from the inner ear to the brain.

Key Terms

Writing Definitions

1. Sensation is the process by which we detectphysical energy from the environment and en-code it as neural signals. (p. 197)

2. Perception is the process by which we select,organize, and interpret sensory information. (p. 197)

3. Bottom-up processing is analysis that beginswith the sensory receptors and works up to thebrain’s integration of sensory information. (p. 197)

4. Top-down processing is information processingguided by higher-level mental processes. (p. 197)

5. Psychophysics is the study of relationshipsbetween the physical characteristics of stimuliand our psychological experience of them. (p. 199)

6. The absolute threshold is the minimum stimula-tion needed to detect a stimulus 50 percent of thetime. (p. 199)

7. Signal detection theory explains precisely howand when we detect the presence of a faint stimu-lus (“signal”). Detection depends partly on expe-rience, expectations, motivation, and alertness. (p.199)

8. A stimulus that is subliminal is one that is belowthe absolute threshold for conscious awareness.(p. 200)Memory aid: Limen is the Latin word for “thresh-old.” A stimulus that is subliminal is one that issub- (“below”) the limen, or threshold.

9. Priming is the activation of an association by animperceptible stimulus, the effect of which is topredispose a perception, memory, or response.(p. 200)

10. The difference threshold (also called the justnoticeable difference, or jnd), is the minimum dif-ference between two stimuli that a subject candetect 50 percent of the time. (p. 201)

11. Weber’s law states that the just noticeable differ-ence between two stimuli is a constant minimumproportion of the stimulus. (p. 202)Example: If a difference of 10 percent in weight isnoticeable, Weber’s law predicts that a personcould discriminate 10- and 11-pound weights or50- and 55-pound weights.

12. Sensory adaptation refers to the decreased sensi-tivity that occurs with continued exposure to anunchanging stimulus. (p. 202)

13. In sensation, transduction refers to the process bywhich receptor cells in the eye, ear, skin, and noseconvert stimulus energies into neural impulses.(p. 204)

Answers 151

14. Wavelength, which refers to the distance fromthe peak of one light (or sound) wave to the next,gives rise to the perceptual experiences of hue, orcolor, in vision (and pitch in sound). (pp.204–205)

15. The intensity of light and sound is determined bythe amplitude of the waves and is experienced asbrightness and loudness, respectively. (p. 205)Example: Sounds that exceed 85 decibels in ampli-tude, or intensity, will damage the auditory system.

16. The pupil is the adjustable opening in the eyethrough which light enters. (205)

17. The iris is a ring of muscle tissue that forms thecolored part of the eye that controls the diameterof the pupil. (p. 205)

18. The lens is the transparent structure of the eyebehind the pupil that changes shape to focusimages on the retina. (p. 205)

19. Accommodation is the process by which the lensof the eye changes shape to focus near objects onthe retina. (p. 205)

20. The retina is the light-sensitive, multilayeredinner surface of the eye that contains the rods andcones as well as neurons that form the beginningof the optic nerve. (p. 205)

21. Acuity refers to the sharpness of vision. (p. 206)Example: If your acuity is 20/10, you are able tosee clearly at a distance of 20 feet a visual detailthat most people cannot see beyond a distance of10 feet.

22. Nearsightedness is a condition in which nearbyobjects are seen clearly but distant objects areblurred because light rays reflecting from themconverge in front of the retina. (p. 206)

23. Farsightedness is a condition in which distantobjects are seen clearly but nearby objects areblurred because light rays reflecting from themstrike the retina before converging. (p. 206)Memory aid: To help you remember that farsight-edness is caused by a shorter-than-normal eye-ball, think of something falling “far short of themark.”

24. The rods and cones are visual receptors thattransduce light into neural impulses. The rods areconcentrated in the periphery of the retina, thecones in the fovea. The rods have poor sensitivity;detect black, white, and gray; function well indim light; and are needed for peripheral vision.The cones have excellent sensitivity, enable colorvision, and function best in daylight or brightlight. (p. 206)

25. Comprised of the axons of retinal ganglion cells,the optic nerve carries neural impulses from theeye to the brain. (pp. 206–207)

26. The blind spot is the region of the retina wherethe optic nerve leaves the eye. Because there areno rods or cones in this area, there is no visionhere. (p. 207)

27. The fovea is the retina’s point of central focus. Itcontains only cones; therefore, images focused onthe fovea are the clearest. (p. 207)

28. Feature detectors, located in the visual cortex ofthe brain, are nerve cells that selectively respondto specific visual features, such as movement,shape, or angle. Feature detectors are evidentlythe basis of visual information processing. (p. 209)

29. Parallel processing is information processing inwhich several aspects of a stimulus, such as lightor sound, are processed simultaneously. (p. 210)

30. The Young-Helmholtz trichromatic (three-color)theory maintains that the retina contains red-,green-, and blue-sensitive color receptors that incombination can produce the perception of anycolor. This theory explains the first stage of colorprocessing. (p. 212)

31. The opponent-process theory maintains thatcolor vision depends on pairs of opposing retinalprocesses (red-green, yellow-blue, and white-black). This theory explains the second stage ofcolor processing. (p. 213)

32. Color constancy is the perception that familiarobjects have consistent color despite changes in il-lumination that shift the wavelengths they reflect.(pp. 213–214)

33. Audition refers to the sense of hearing. (p. 215) 34. The pitch of a sound is determined by its fre-

quency, that is, the number of complete wave-lengths that can pass a point in a given time.Frequency, in turn, is directly related to wave-length: longer waves produce lower pitch; shorterwaves produce higher pitch. (p. 216)

35. The middle ear is the chamber between theeardrum and cochlea containing the three bones(hammer, anvil, and stirrup) that concentrate theeardrum’s vibrations on the cochlea’s oval win-dow. (p. 217)

36. The inner ear contains the semicircular canalsand the cochlea, which includes the receptors thattransduce sound energy into neural impulses.Because it also contains the vestibular sac, theinner ear plays an important role in balance, aswell as in audition. (p. 217)


Answers 153

37. The cochlea is the coiled, bony, fluid-filled tube ofthe inner ear where the transduction of soundwaves into neural impulses occurs. (p. 217)

38. The place theory of hearing states that we heardifferent pitches because sound waves of variousfrequencies trigger activity at different places onthe cochlea’s basilar membrane. (p. 219)Memory aid: Place theory maintains that the placeof maximum vibration along the cochlea’s mem-brane is the basis of pitch discrimination.

39. The frequency theory of hearing presumes thatthe rate, or frequency, of nerve impulses in theauditory nerve matches the frequency of a tone,thus enabling us to sense its pitch. (p. 219)

40. Conduction hearing loss refers to the hearing lossthat results from damage in the mechanics of theouter or middle ear, which impairs the conduc-tion of sound waves to the cochlea. (p. 220)

41. Sensorineural hearing loss (nerve deafness) ishearing loss caused by damage to the auditoryreceptors of the cochlea or to the auditory nervedue to disease, aging, or prolonged exposure toear-splitting noise. (p. 220)

42. A cochlear implant is an electronic device thatconverts sounds into electrical signals that stimu-late the auditory nerve. (p. 221)

43. Melzack and Wall’s gate-control theory maintainsthat a “gate” in the spinal cord determineswhether pain signals are permitted to reach thebrain. Neural activity in small nerve fibers opensthe gates; activity in large fibers or informationfrom the brain closes the gate. (p. 227)Example: The gate-control theory gained supportwith the discovery of endorphins. Production of

these opiatelike chemicals may be the brain’smechanism for closing the spinal gate.

44. Sensory interaction is the principle that one sensemay influence another. (p. 230)

45. Kinesthesis is the sense of the position and move-ment of the parts of the body. (p. 233)

46. The sense of body movement and position,including the sense of balance, is called thevestibular sense. (p. 234)

Cross-Check

ACROSS DOWN

1. fovea 1. frequency7. large 2. farsighted

12. optic 3. electromagnetic13. intensity 4. feature detector14. nanometer 5. cochlear implant15. hue 6. top16. eardrum 8. kinesthesis17. afterimage 9. blindsight19. amplitude 10. psychophysics21. conduction 11. context22. oval 18. blindspot28. pupil 20. lens29. audition 23. acuity30. cornea 24. middle31. retina 25. inner

26. place27. rods


FOCUS ON VOCABULARY AND LANGUAGE

Page 198: Shown her own face in a mirror she isagain stumped. This person (E. H.) is suffering fromprosopagnosia and cannot recognize faces and evenfails (she is stumped) to recognize her own face in themirror. What is interesting in this case is that she canprocess incoming sensory information (bottom up)but is unable to make any sense of it (top down). AsMyers notes earlier, she has sensation (bottom-up pro-cessing), but her perception (top-down processing) isnot working properly.

Sensing the World: Some Basic Principles

Page 198: A frog could starve to death knee-deep inmotionless flies. But let one zoom by and the frog’s“bug detector” cells snap awake. The frog’s eyes andbrain are organized in such a way that only fastmoving (zooming), small, dark objects will causethese specialized feature detector nerve cells (“bugdetectors”) to become active (snap awake). If the frog issurrounded by flies that don’t move (knee-deep inmotionless flies), it will die of hunger, completelyunaware of the food at its feet.

Page 199: The shades on our senses are open just acrack, allowing us only a restricted awareness of thisvast sea of energy. Just as sunblinds or curtains(shades) let only a little light in through any smallopening (a crack), our sensory system is only able todetect a very small part of the large amount (vast sea)of the physical energy that exists in the world.

Page 199: Exhausted parents of a newborn willnotice the faintest whimper from the cradle. . . . In sig-nal detection theory there is no single absolutethreshold for detecting stimuli; it all depends on thesituation. Thus, parents who are sleeping soundlyare more likely to become aware of the quietest cryof distress (the faintest whimper) from the infant in itssmall bed (cradle) than much louder but irrelevantnoise.

Page 200: . . . ”satanic messages” . . . It has been sug-gested that some rock music recordings have hiddenor subliminal messages and that behavior can beinfluenced or manipulated by them (i.e., hidden per-suasion). Claims have been made that some of thesemessages are antireligious and promote devil wor-ship (diabolical or satanic). As Myers makes clear,there is not a shred of evidence to support theseideas.

Page 201: . . . hucksters . . . A huckster is someone whosells merchandise that may be of dubious value.Those who promote and sell subliminal tapes (huck-sters) make claims that are not supported by scientif-

ic research. In fact, the available evidence suggeststhat subliminal tapes do not have the profound,enduring effects on behavior claimed by their mar-keters.

Page 202: . . . it might take a £4000 price hike in a£40,000 Mercedes to raise the eyebrows of its potentialbuyers. Raised eyebrows express surprise. So a £4000increase in the cost (price hike) of a luxury car(Mercedes-Benz), which normally costs £40,000,would be noticed by interested buyers (would raisetheir eyebrows). Weber’s law states that a constantproportion of the original stimulus is needed inorder for the difference to be detected, and the pre-cise proportion will change depending on the stimu-lus. Thus, a $5 increase in the price of the car wouldnot be a just noticeable difference, or jnd, but a $5dollar increase (price hike) in the cost of a hamburgerand fries would exceed a jnd.

Page 202: So everywhere that Mary looks, the scene issure to go. In order to understand this sentence youneed to be familiar with the old nursery rhyme:Mary had a little lamb, its fleece was white as snow,and everywhere that Mary went the lamb was sure to go.When a volunteer (Mary) is fitted with a special con-tact lens and miniature projector she sees the sameimage no matter where her eyes “look” (everywherethat Mary looks the scene is sure to go). When an imageis projected onto the retina in this manner the scenedisappears bit by bit and then reappears and disap-pears again (in meaningful units). This happensbecause the image, which normally would be mov-ing back and forth rapidly (quivering) as a result oftiny eye movements, is now stationary with respectto the retina and its receptors. As the receptorsfatigue the image disappears.

Vision

Page 207: . . . blind spot . . . You can use the sugges-tion in Figure 5.10 of your text to demonstrate thatthere are two small parts of your visual field (one inthe left and one in the right) where you have nosight. These tiny areas (blind spots) are where theoptic nerve exits the eye.

Page 207: Rods have no such hotline [to the brain]. . . .Cones, which are mostly clustered in the fovea anddetect color and fine detail, have many more indi-vidual connections to the brain than the rods. Rods,which give us our black-and-white vision, have toshare bipolar cells and so do not have as many indi-vidual connections (hotlines) to the brain (in dimlight, however, this can be an advantage as severalrods can focus or funnel their individual faint ener-gy output onto a single bipolar cell).

Focus on Vocabulary and Language 155

Page 210 (caption): The answer to this question is theHoly Grail of vision research. The reference here is tothe medieval legend that the cup (grail) Jesus Christdrank from at the Last Supper, and which was laterused to catch his blood when he was crucified, sur-vived and may have been brought to England. Thequest, or search, for this sacred cup (Holy Grail) sym-bolized spiritual regeneration and enlightenment.Similarly, attempting to answer the question abouthow the brain deals with multiple aspects of a visualscene at the same time, automatically, and withoutour awareness (parallel processing), is an importantundertaking that, if successful, will enlighten usabout brain functioning (the Holy Grail of visionresearch).

Page 211: . . . blindsight . . . Blindsight refers to the factthat some people with neurological damage havethe ability to see, to some degree, without any con-scious awareness of the visual experience. They areblind, yet they can see (blindsight). This suggests thatthere are two parallel processing systems operating,one that unconsciously guides our actions (the zom-bie within), and one that gives us our conscious per-ceptions.

Page 212: Color, like all aspects of vision, resides notin the object but in the theater of our brains. Myersnotes that when we view a colored object (for exam-ple, a blue balloon), it absorbs all the wavelengthsexcept its own (blue) and reflects the wavelengths ofblue back to us. The color we perceive is a productof our brain and exists only in the perceiver’s mind(theater of the brain).

Hearing

Page 215: We also are remarkably sensitive to faintsounds, an obvious boon for our ancestors’ survivalwhen hunting or being hunted or detecting a child’swhimper. Humans are very good at detecting veryquiet noises (faint sounds), which was clearly benefi-cial (a boon) to our predecessors’ ability to survivewhen they were both predator (hunter) and prey(being hunted). Likewise, the ability to notice andrespond to a youngster's quiet cry of distress (achild's whimper) would have had adaptive value. Weare also very sensitive to changes in sounds and wehave the ability to differentiate among thousands ofhuman voices.

Page 216: A piccolo produces much shorter, fastersound waves than does a tuba. Musical instrumentsproduce stimulus energy called sound waves—molecules of air that bump and push each other

along—and these may be long (low frequency) orshort (high frequency). A tuba (a large, deep-toned,brass-wind instrument) produces low-frequencysound waves and thus has a lower pitch than a picco-lo (a small flute), which produces high-frequencywaves and has a higher pitch.

Page 218 (Close-Up): If only our ears had earlids.Myers makes it clear that prolonged exposure toloud and unpredictable noise can affect our well-being and seriously damage our hearing. So, in anoisy urban environment it would be nice if wecould close our ears (with earlids) as we can our eyes(with eyelids).

Page 219: If a car to the right honks, your right earreceives a more intense sound, and it receives soundslightly sooner than your left ear. We locate soundsbecause our ears are about 6 inches apart and thereis a time, as well as a loudness difference, betweenauditory reception in each ear. If we hear the soundof a car horn (it honks) to our right, the left earreceives a less intense sound somewhat later thanthe right ear, and thus we locate the direction of thesound to the right.

Page 220: That is why, when trying to pinpoint asound, you cock your head, so that your two ears willreceive slightly different messages. When a sound isequidistant from our two ears (directly ahead,behind, or above), and there is no visual clue, wehave trouble locating (pinpointing) the source. Inthis situation it helps to tilt (cock) our heads so thateach ear receives a slightly different message (thesound will be a little louder and sensed a little soon-er by one ear, and the brain uses this information todetect where the sound is coming from).

Page 220: Occasionally, disease causes sensorineuralhearing loss, but more often the culprits are biologi-cal changes linked with heredity, aging and pro-longed exposure to ear-splitting noise or music(Figure 5.26). Sensorineural hearing loss, or nervedeafness (cochlear damage), can sometimes becaused by illness, but the agents responsible (the cul-prits) are more likely to be age-related biological fac-tors and extended encounters with extremely loud(ear-splitting) music or noise. While digital hearingaids are a partial remedy, the latest cochlearimplants can restore hearing for children and mostadults.

Other Important Senses

Page 224: As lovers, we yearn to touch—to kiss, tostroke, to snuggle. Our sense of touch involves a mix-ture of at least four distinct senses: pressure,

warmth, cold, and pain. Intimate relations ofteninvolve a desire or longing (we yearn) to caress, kiss,and closely embrace each other (snuggle).

Page 227: Rubbing the area around your stubbed toewill create competing stimulation that will blocksome of the pain messages. If you hit your toeagainst a solid object (stub your toe), it really hurts. If,however, you massage (rub) the part around the sorespot, it makes you feel better because stimulationinterferes with (blocks) some of the pain messages.This supports the gate-control model, which sug-gests that this stimulation (rubbing) will activate“gate-closing” in large neural fibers and, thus, willreduce pain.

Page 228: Sometimes the pain in sprain is mainly in thebrain. Myers is doing a parody of the lyrics from asong in the musical My Fair Lady, “The rain in Spainstays mainly in the plain.” The main point: reportsof repetitive strain injury (the pain in sprain) were, inthe case of groups (pockets) of Australian keyboardoperators, due to social and psychological influences(mainly in the brain) and were not the result of dam-aged ligaments or muscles in the hands or arms, asis usually the case.

Page 228 (caption): After explaining heat-diffusionprinciples that permit firewalking, he then joined sev-eral others in putting his feet where his mouth was. Theexpression “put your money where your mouth is”means that you should be willing to back or supportyour words or claims with appropriate behavior. Sophysicist David Willey was willing to support hisexplanation of firewalking, which was based on sci-entific facts, by taking the necessary action. By actu-ally walking or stepping across the hot coals withoutburning his bare feet, he put his feet (firewalking)where his mouth was (his scientific explanation) andshowed that the claims of the “mind over matter”promoters were wrong in this case.

Page 229: A well-trained nurse may distract needle-shy patients by chatting with them and asking themto look away when inserting the needle. Onemethod of pain control is through distraction. If youare nervous or anxious about being injected with a

hypodermic needle (a needle-shy patient), the nursemay talk to you about unimportant matters (shechats with you) and request that you do not watch theprocedure. This type of distraction can reduce theintensity of the pain.

Page 230: Taste buds are certainly essential for taste,but there is more to taste than meets the tongue. Thecommon expression “there is more to this than meetsthe eye” suggests that there is something extra goingon over and above the obvious or apparent. Myerscreates a variation of this expression using a differ-ent sense (taste). The flavors we experience are afunction of more than just the taste buds in thetongue; they involve sensory interaction with thesense of smell (olfaction). Thus, the sense of tasteinvolves more than simply responding to the chemi-cals that stimulate taste receptors in the tongue(there is more to taste than meets the tongue).

Page 231: Each day, you inhale and exhale nearly20,000 breaths of life-sustaining air, bathing yournostrils in a stream of scent-laden molecules. Smell(olfaction) is a chemical sense and as substances(flowers, feet, fish, fertilizer, etc.) release molecules,they are carried by the air we breathe (a stream ofscent-laden molecules) and wash over (bathe) receptorsin our nasal cavities (nostrils).

Page 232: Words more readily portray the sound ofcoffee brewing than its aroma. It is easier to talkabout and describe (portray) the subtle aspects ofcoffee brewing than to put into words the sensoryqualities involved in the smell (aroma) of coffee.Olfaction seems to be a more primitive sense thanvision or audition.

Page 234: The biological gyroscopes for this sense ofequilibrium are in the inner ear. A gyroscope is amechanical device used as a stabilizer in navigationand scientific instruments. Likewise, we have bio-logical stabilizers that monitor the movement andposition of our bodies and provide us with a senseof balance (equilibrium). They are called the semicir-cular canals and the vestibular sacs and are located inthe inner ear.


Documents

Chapter 5 Sensation, Myers Psychology 8e