Chapter 6: Sensation And Perception

Question 1

Sensation

Answer 1

• process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment
• detection of information by your senses and transmission if this information to your brain

Question 2

Perception

Answer 2

• process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events
• process by which your brain organizes and interprets sensory input
• if selectively impaired for faces, this would allow you to recognize people from their hair, gait, voice, or particular physique, but not just their face

Question 3

Transduction

Answer 3

• the conversation of one form of energy into another
• in sensation, this is the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret

Question 4

Absolute Threshold

Answer 4

• minimum stimulation needed to detect a particular stimulus 50 percent of the time
• would be tested for if a hearing specialist exposed each of your ears to varying sound levels and, for each tone, the test defined where half the time you could detect the sound and half the time you could not

Question 5

Difference Threshold

Answer 5

• the minimum difference between two stimuli required for detection 50 percent of the time
• is also known as the just noticeable difference (jnd)

Question 6

Weber’s Law

Answer 6

• principal that, to be perceived as different, two stimuli must differ by a constant minimum percentage(rather than a constant amount)
• law that accounts for the fact that if you add 1 ounce to a 10-ounce weight then you will detect the difference, but if you add 1 ounce to a 100-ounce weight then you probably will not
• states that two lights must differ in intensity by 8 percent in order for an average person to perceive this difference
• states that two objects must differ in weight by 2 percent in order for an average person to perceive this difference
• states that two tones must differ in frequency by 0.3 percent in order for an average person to perceive this difference

Question 7

Sensory Adaptation

Answer 7

• a diminished sensitivity as a consequence of constant stimulation
• is occurring if, after standing for several minutes in a smelly room, you no longer notice the smell
• is occurring if, after moving your watch up your wrist an inch and then waiting a few moments, you no longer feel it
• is prevented from occurring when we stare at an object without flinching because our eyes are always moving
• although it reduces our sensitivity, this offers an important benefit: freedom to focus on informative changes in our environment without being distracted

Question 8

Perceptual Set

Answer 8

• a mental predisposition to perceive one thing and not another
• would be a belief that influences what you hear, taste, feel, or see
• would be occurring if a newspaper caption about a monster creates in you an expectation that makes you see a curved tree trunk in a photo as a monster
• was occurring when a co-pilot, expecting to hear the usual “gear up” command, raised the planes wheels when the pilot told him to “cheer up”

Question 9

Wavelength

Answer 9

• the distance from the peak of one light or sound wave to the peak of the next
• physical property of electromagnetic energy that varies from the short blips of cosmic rays to the long pulses of radio transmission
• physical property of light waves that determines the dimension of color
• property of waves that is inversely related to their frequency, where the lower the frequency of the wave is then the greater this will be

Question 10

Intensity

Answer 10

• the amount of energy in a light or sound wave as determined by the wave’s amplitude
• physical property of light waves that determines the dimension of brightness
• physical property of sound waves that determines the dimension of loudness

Question 11

Pupil

Answer 11

• the adjustable opening in the center of the eye through which light enters
• part of the eye that dilates or constricts in response to light intensity and even to inner emotions
• part of your eye that dilates and gives your eyes a darker appearance when you’re feeling amorous and interested in someone else
• part of your eyes that dilates when you enter a darkened theater or turn off the light at night

Question 12

Lens

Answer 12

• the transparent structure behind the pupil that changes shape to help focus images on the retina
• part of the eye that has its curvature and thickness changed to bring nearby or distant objects into focus on the retina

Question 13

Retina

Answer 13

• the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information
• is a multilayered tissue on the eyeball’s sensitive inner surface

Question 14

Rods

Answer 14

• sensory receptors that detect black, white, and gray

- sensory receptors that are necessary for peripheral and twilight vision

Question 15

Cones

Answer 15

• sensory receptors that are concentrated near the center of the retina (fovea) and that function in daylight or in well-lit conditions
• sensory receptors that detect fine detail and give rise to color sensations

Question 16

Blind Spot

Answer 16

• the point at which the optic nerve leaves the eye and there are no receptor cells located there
• responsible for normally creating a lack of sensation from an area of the visual field of each eye, but for which your brain automatically compensates by filling in this black hole

Question 17

Young-Helmholtz Trichromatic Theory

Answer 17

• the theory that the retina contains three different color receptors - one most sensitive to red, one to green, one to blue - which, when stimulated in combination, can produce the perception of any color
• theory that states that we see yellow by mixing red and green light, which stimulates both red-sensitive and green-sensitive cones
• theory of color vision that has trouble explaining how people blind to red and green only (the most common type of color-blindness) can often still see yellow

Question 18

Opponent-process Theory

Answer 18

• theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision
• theory of color vision that states that some cells are stimulated by green and inhibited by red, while others are stimulated red and inhibited by green
• theory of color vision that was based on the observation that the after image produced by staring at red is green and vice versa

Question 19

Frequency

Answer 19

• frequency of complete wavelengths that pass a point in a given time (for example, per second)
• physical property of sound waves that determines the dimension of pitch: a tone’s experienced highness or lowness
• physical property of sound waves that when low is perceived as a low pitch note, and that when high is perceived as a high pitch note

Question 20

Middle Ear

Answer 20

• the chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea’s oval window
• damage to this area of the ear will produce conduction hearing loss: hearing loss caused by damage to the mechanical system that conducts sound waves to the inner ear

Question 21

Cochlea

Answer 21

• coiled, bony, fluid-filled tube in the inner ear
• where sound waves trigger nerve impulses when they travel through its fluid and cause it’s hair cells to bend
• where the sensory receptors for audition -it’s hair cells- are located
• damage to this area of the ear will produce sensorineural hearing loss (also known as nerve deafness): hearing loss caused by damage to this structure’s receptor cells or to the auditory nerves that exit it

Question 22

Place Theory

Answer 22

• the theory of pitch perception that links the pitch we hear with the place where the cochlea’s membrane is stimulated
• according to this theory of pitch perception, higher frequency sound waves produce larger vibrations near the beginning of the cochlea’s membrane, while the lower frequency ones do so near the end of the cochlea’s membrane
• theory of a pitch perception that cannot explain how we distinguish between low-frequency sound waves since the neural signals they generate are not so neatly localized on the basilar membrane

Question 23

Frequency Theory

Answer 23

• the theory of pitch perception that notes the fact that the rate of nerve impulses travelling up the auditory nerve matches the frequency of a tone
• theory of pitch perception that cannot explain how we distinguish between high-frequency sound waves (greater than 1000 waves per second) since an individual neuron cannot fire faster than 1000 times per second

Question 24

Sound Localization

Answer 24

-enables you to determine the spatial origins of auditory events

-process that has two mechanisms:
•assessments of the relative timing and of the relative intensity of sounds that arrive at each ear

Question 25

Skin Receptor

Answer 25

• type of sensory receptor that detects touch sensations

- type of sensory receptor that has four basic variations: pressure, warmth, cold, and pain

Question 26

Taste Bud

Answer 26

• contains 50 to 100 taste receptors which project antenna-like hairs that sense food molecules
• there are 200 or more of these inside each little bump on the top and sides of your tongue
• contains one of five basic types of sensory receptors: sweet, salty, sour, bitter, and umami

Question 27

Olfactory Receptor

Answer 27

• type of sensory receptor that detects smell sensations
• type of sensory receptor that is located at the top of each nasal cavity
• type of sensory receptor that has many different types which are stimulated in combination to produce the 10,000 odors we can detect

Question 28

Kinesthetic Sensor

Answer 28

• type of sensory receptor that detects the position and movement of individual body parts
• type of sensory receptor that is located in your joints and tendons

Question 29

Vestibular Receptor

Answer 29

• type of sensory receptor that detects your head’s (and thus your body’s) position and movement, and thus allows us to maintain balance
• type of sensory receptor that consists of hair cells located in two structures of the inner ear: the semicircular canals for detecting the direction of head acceleration and the vestibular sacs for detecting the position of the head
• type of sensory receptor that sends messages to the cerebellum at the back of your brain

Question 30

Figure-Ground

Answer 30

• is the organization of the visual field into objects that stand out from their surroundings
• is the organization of the visual field that would separate words from the background white paper they are printed on

Question 31

Gestalt Laws of Organization

Answer 31

• the principles that explain our perceptual tendency to organize stimuli into coherent group
• rules, applied even by infants, that illustrate how the perceived whole differs from the sum of its parts
• includes the principle of proximity: that we group nearby figures together
• includes the principle continuity: that we perceive smooth, continuous patterns rather than discontinuous ones
• includes the principle of closure: that we fill in gaps to create a complete, whole object

Question 32

Monocular Cues

Answer 32

• are depth cues available to either eye alone
• type of death cues that include relative height: how we perceive objects as being farther away if they are higher in our field of vision than other objects
• type of depth cues that include relative size: how we perceive objects as being farther away if they cast smaller retinal images than other objects we assume to be similar in size
• type of depth cues that include interposition: how we perceive an object as being closer if it partially blocks our view of another object
• type of depth cues that include relative motion: how we perceive objects as being farther away if they seem to move less as we move
• type of depth cues that include linear perpective:how we perceive parallel lines as being farther away the sharper the angle of convergence
• type of depth cues that include light and shadow: how shading produces a sense of depth consistent with our assumption that light comes from above

Question 33

Binocular Cues

Answer 33

• are depth cues that depend on the use of two eyes
• type of depth cues that include retinal disparity: how the brain compares images from the retinas in the two eyes to compute distances

Question 34

Phi Phenomenon

Answer 34

• is an illusion of movement created when two or more adjacent lights blink on and off in quick succession
• illusion that a lighted sign would exploit if it creates an impression of a moving arrow
• is also known as stroboscopic movement: the perception of continuous movement in a rapid series of slightly varying images
• illusion that film animation artists create by flashing 24 still pictures a second
• illusion that allows us to perceive motion in films, which are really just superfast slide shows

Question 35

Perceptual Constancy

Answer 35

• the perception of an object as unchanging even as illumination and retinal images of the object changes
• includes color constancy: perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by an object
• includes brightness (or lightness) constancy: perceiving an object as having a constant brightness, despite variations in its illumination, due to the relative luminance of its surroundings
• includes shape constancy: perceiving the shape of familiar objects as constant even while we view them from different angles
• includes size constancy: perceiving the size of objects as constant even while our distance from then varies