Chapter 5: Sensation Vocab

Front 1

sensation

Back 1

the process by which our sensory receptors and nervous system recieve and represent stimulus energies from our enviornment

Front 2

perception

Back 2

the process of orginizating and interpreting snesory information, enabling us to recognize meaningful objects and events

Front 3

bottom - up processing

Back 3

analysis that begins with the sensory recetops and works up to the brain's intergration of sensory information

Front 4

top - down processing

Back 4

information processing guided by higher-level mental processes, as when we construct perceptions drawing on our expierence and expectations

Front 5

psychophysics

Back 5

the study of relationships between the physical characteristics of the stimuli, such as their intensity, and our psychological experience of them

Front 6

absolute threshold

Back 6

the minimum stimulation needed to detect a particular stimulus 50 percent of the time

Front 7

signal detection theory

Back 7

a theory predicting how and when we detect the presence of a faint stimulus ("signal") amid background stimulation ("noise"). Assumes there is no single absolute threshold and that detection depends partly on a person's expierence, expecatations, motivation, and level of fatigue

Front 8

subliminal

Back 8

below one's absolute threshold for conscious awareness

Front 9

priming

Back 9

the activation, often unconsciously, of certian associations, thus predisposing one's perception, memory, or response

Front 10

difference threshold

Back 10

the minimum difference between two stimuli required for detection 50 percent of the time. We expierence the difference threshold as a just notticable difference

Front 11

Weber's law

Back 11

the principle that, to be perceived as different, two stimuli must differ by a constant minium percentage (rather than a constant amout)

Front 12

sensory adaptation

Back 12

diminished sensitivity as a consequence of constant stimulation

Front 13

transduction

Back 13

conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brains can interpret

Front 14

wavelengh

Back 14

the distance from the peak of one light or sound wave to the peak of the next. Eletromagnetic wavelengths vary from the short blips of cosmic rays to the long pulses of raido transmission

Front 15

hue

Back 15

the dimension of color that is determined by the wavelength of light; what we know as the color names blue, gren and so forth

Front 16

intensity

Back 16

the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave's amplitude

Front 17

pupil

Back 17

the adjustable opening in the center of the eye through which light enters

Front 18

iris

Back 18

a ring of muscle tissue that forms the colored portion of the eye around the pupil opening

Front 19

lens

Back 19

the transparent structure behind the pupil that changes shape to help focus near or far objects on the retina

Front 20

accommodation

Back 20

the process by which the eye's lens changes shape to focus near or far objects on the retina

Front 21

retina

Back 21

the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that being the processing of visual information

Front 22

acuity

Back 22

the sharpness of vision

Front 23

nearsightedness

Back 23

a condition in which nearby objects are seen more clearly than distant objects because distant objects focus in the front of the retina

Front 24

farsightedness

Back 24

a condition in whic far away objects are seen more clearly than near objects because the image if near objects is focused behind the retina

Front 25

rods

Back 25

retinal receptors that detect black, white and gray; necessary for peripheral and twilight vision, when cones don't respond

Front 26

cones

Back 26

retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations

Front 27

optic nerve

Back 27

the nerve that carries neural impulses from the eye to the brain

Front 28

blind spot

Back 28

the point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there

Front 29

fovea

Back 29

the central focal point in the retina, around which the eye's cones cluster

Front 30

parallel processing

Back 30

the processing of several aspects of a problem simultaneously; the brain's natural mode of information processing for many functions, including vision. Contrasts with the step-by-step (serial) processing of most computers and of conscious problem solving

Front 31

Young-Helmholtz trichromatic (three color) theory

Back 31

the theory that the retina contains three different color receptors - one most sensitive to red, one to green, and one to blue - which when stimulated in combination can produce the perception of any color

Front 32

opponent-process theory

Back 32

the theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. For exapmle, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green

Front 33

color constancy

Back 33

perceiving familiar objects as having consistent color, even if changing illumination alters the waverlengths reflected by the object

Front 34

audition

Back 34

the sense or act of hearing

Front 35

frequency

Back 35

the number of complete wavelenths that pass a point in a given time (for example, per second)

Front 36

pitch

Back 36

a tone's experienced highness or lowness; depends on frequency

Front 37

middle ear

Back 37

the chamber between the eardrum and the cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea's oval window

Front 38

cochlea

Back 38

a coiled, bony, fluid-filled tube in the inner ear through which the sound waves trigger nerve impulses

Front 39

inner ear

Back 39

the intermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs

Front 40

place theory

Back 40

in hearing, the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated

Front 41

frequency theory

Back 41

in hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of the tone, thus enabling us to sense its pitch

Front 42

conduction hearing loss

Back 42

hearing loss caused by damage to the mechanical system the conducts sound waves to the cochlea

Front 43

sensorineural hearing loss

Back 43

hearing loss caused by damage to the cochlea's receptor cells or to the auditory nerves; also called verve deftness

Front 44

cochlear implant

Back 44

a device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea

Front 45

gate-control theory

Back 45

the theory that the spinal cord contains a neurological "gate" that blocks pains signals or allows them to pass on to the brain. The "gate" is opened by the activity of pain signals traveling up small nerve fibers and is closed by activity in larger fibers or by information coming from the brain

Front 46

sensory interaction

Back 46

teh principle that one sense may influence another, as when the smell of food influences taste

Front 47

kinesthesis

Back 47

the system for sensing the position and movement of individual body parts

Front 48

vestibular sense

Back 48

the sense of body movement and position, including the sense of balance

Front 49

feature detectors

Back 49

nerve cells in the brain the respond to specific features of the stimulus, such as shape, angle or movement