Chapter 3

Question 1

attention

Answer 1

conscious awareness; can be focused on events that are taking place in the environment or inside our minds

Question 2

sensation

Answer 2

the process through which our sense organs convert environmental energy such as light and sound into neural signals

Question 3

perception

Answer 3

the process through which we interpret sensory information

Question 4

psychophysics

Answer 4

the study of how the mind interprets the physical properties of stimuli

Question 5

absolute threshold

Answer 5

the minimum intensity of a stimulus at which participants can identify its presence 50% of the time

Question 6

signal detection theory

Answer 6

states that our ability to detect the presence of a stimulus is affected by more than just the intensity of that stimulus. Factors such as fatigue, motivation, and attention may also affect these judgments

Question 7

just noticeable difference (jnd)

Answer 7

the minimum change in intensity of a stimulus that participants can detect 50% of the time

Question 8

Weber’s [VAY-bers] law

Answer 8

a psychological principle that states that for each of our five senses, the amount of change in the stimulus that is necessary to produce a jnd depends on the intensity at which the stimulus is first presented

Question 9

subliminal perception

Answer 9

when the intensity of a stimulus is below the participant’s absolute threshold and the participant is not consciously aware of the stimulus

Question 10

extrasensory perception (ESP)

Answer 10

also known as psi, the ability to acquire information about the world without using the known senses

Question 11

wavelength

Answer 11

a physical property of some energies that corresponds to the distance between wave peaks

Question 12

saturation

Answer 12

the purity of light; light that consists of a single wavelength produces the richest or most saturated color

Question 13

brightness

Answer 13

the intensity of light; it corresponds to the amplitude of the light waves

Question 14

hue

Answer 14

the color of light; it corresponds to the light’s wavelength

Question 15

visible spectrum

Answer 15

the spectrum of light that humans can see

Question 16

amplitude

Answer 16

a physical property of some energies that corresponds to the height of wave peaks

Question 17

cornea [COR-nee-ah]

Answer 17

the clear, slightly bulging outer surface of the eye that both protects the eye and begins the focusing process

Question 18

pupil

Answer 18

the hole in the iris through which light enters the eye

Question 19

lens

Answer 19

the part of the eye that lies behind the pupil and focuses light rays on the retina

Question 20

accommodation

Answer 20

the process through which the lens is stretched or squeezed to focus light on the retina

Question 21

retina

Answer 21

structure at the back of the eye that contains cells that convert light into neural signals

Question 22

optic nerve

Answer 22

the the structure that conveys visual information away from the retina to the brain

Question 23

blindspot

Answer 23

the point where the optic nerve leaves the retina (the optic disk) where there are no rods or cones

Question 24

photopigments

Answer 24

light-sensitive chemicals that create electrical charges when they come into contact with light

Question 25

cones

Answer 25

the cells of the retina that are sensitive to specific colors of light and send information to the brain concerning the colors we are seeing

Question 26

rods

Answer 26

the light-sensitive cells of the retina that pick up any type of light energy and convert it to neural signals

Question 27

dark adaptation

Answer 27

the process through which our eyes adjust to dark conditions after having been exposed to bright light

Question 28

light adaptation

Answer 28

the process through which our eyes adjust to bright light after having been exposed to darkness

Question 29

trichromatic theory of color vision

Answer 29

the idea that color vision is made possible by the presence of three different types of cones in the retina that react respectively to red, green, or blue light

Question 30

color blindness

Answer 30

a condition in which a person cannot perceive one or more colors because of altered cone activity in the retina

Question 31

opponent-process theory

Answer 31

the idea that we have dual-action cells beyond the level of the retina that signal the brain when we see one of a pair of colors

Question 32

optic chiasm

Answer 32

the point in the brain where the optic nerve from the left eye meets the optic nerve from the right eye

Question 33

cycle

Answer 33

a physical characteristic of energy defined as a wave peak and the valley that immediately follows it

Question 34

frequency

Answer 34

a physical characteristic of energy defined as the number of cycles that occur in a given unit of time

Question 35

loudness

Answer 35

the psychophysical property of sound that corresponds to the AMPLITUDE of a sound wave

Question 36

decibels (dB)

Answer 36

the unit of measurement used to describe the loudness of a sound

Question 37

pitch

Answer 37

the psychophysical property of sound that corresponds to the FREQUENCY of a sound wave

Question 38

outer ear

Answer 38

the outermost parts of the ear, including the pinna, auditory canal, and surface of the eardrum

Question 39

middle ear

Answer 39

the part of the ear behind the eardrum and in front of the oval window, including the hammer, anvil, and stirrup

Question 40

inner ear

Answer 40

the innermost portion of the ear that includes the cochlea

Question 41

hair cells

Answer 41

neurons that grow out of the basilar membrane and convert sound waves into neural impulses

Question 42

auditory nerve

Answer 42

the nerve that carries information from the inner ear to the brain

Question 43

basilar membrane

Answer 43

the structure in the cochlear duct that contains the hair cells, which convert sound waves into neural impulses

Question 44

cochlea

Answer 44

the curled, fluid-filled tube in the inner ear that contains the basilar membrane

Question 45

place theory

Answer 45

a theory that proposes that our brain decodes pitch by noticing which region of the basilar membrane is most active

Question 46

frequency theory

Answer 46

a theory that proposes that our brain decodes pitch directly from the frequency at which the hair cells of the basilar membrane are firing

Question 47

volley theory

Answer 47

a theory that proposes that our brain decodes pitch by noticing the frequency at which groups of hair cells on the basilar membrane are firing