Psych 101 Chapters 4-7 Vocabulary

Transducers

Devices that convert one kind of energy into another

sensation

conversion of energy from the environment into a pattern of response by the nervous system; also, a sensory impression

Psychophysics

study of how the mind interprets the physical properties of stimuli

Absolute Threshold

minimum amount of physical energy that can be detected 50% of the time

difference thresholds

minimum difference in physical energy between two stimuli that can be detected 50% of the time

sensory adaptation

a decrease over time in sensory response to an unchanging stimulus

perceptual features

basic attributes of a stimulus, such as lines, shapes, edges, or colors

feature detector

cells in the cortex that respond to a specific attribute of an object

hue

color of light, as determined by its wavelength

cornea

curved, transparent, protective layer through which light enters the eye

lens

clear structure behind the pupil that bends light toward the retina

accommodation

changes in the shape of the lens of the eye to enable the seeing of close and far objects

hyperopia (farsightedness)

having difficulty focusing on nearby objects

myopia (nearsightedness)

having difficulty focusing on distant objects

astigmatism

defects in the cornea, lens, or eye that cause some areas of vision to be out of focus

presbyopia

farsightedness caused by aging

retina

surface at the back of the eye onto which the lens focuses light rays

cones

photoreceptors that are sensitive to color

rods

photoreceptors for dim light that produce only black and white sensations

visual activity

the sharpness of visual perception

blind spot

area in the retina where the optic nerve exits that contains no photoreceptor cells

optic nerve

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

fovea

tiny spot in the center of the retina, containing only cones, where visual acuity is greatest

color blindness

a total inability to perceive color

color weakness

an inability to distinguish some colors

peripheral vision

vision at the edges of the visual field

dark adaptation

increased light sensitivity of the eye under low-light conditions

pupil

the black opening inside the iris that allows light to enter the eye

iris

colored structure on the surface of the eye surrounding the pupil

trichromatic theory of color vision

a theory of color vision based on three cone types: red, gren, and blue

opponent-process theory of color vision

proposition that color vision is based on coding things as red or green, yellow or blue, or black or white

pitch

how high or low a tone sounds related to the frequency of a sound wave

loudness

the volume of a sound; related to the amplitude of a sound wave

eardrum

membrane that vibrates in response to sound waves and transmits them inward

cochlea

snail-shaped organ in the inner ear that contains sensory receptors for hearing

basilar membrane

structure in the cochlea containing hair cells that convert sound waves into action potentials

hair cells

receptor cells within the cochlea that transduce vibrations into nerve impulses

conductive hearing loss

poor transfer of sounds from the eardrum to the inner ear

sensorineural hearing loss

loss of hearing caused by damage to the inner ear hair cells or auditory nerve

noise induced hearing loss

damage caused by exposing the hair cells to excessively loud sounds

frequency theory of hearing

proposition that pitch is decoded from the rate at which hair cells of the basilar membrane are firing

place theory of hearing

proposition that higher and lower tones excite specific areas of the cochlea

olfaction

sense of smell

gustation

sense of taste

skin senses

the senses of touch, pressure, pain, heat, and cold

kinesthetic senses

the senses of body movement and positioning

vestibular senses

perception of balance, gravity, and acceleration

lock and key theory of olfaction

a theory holding that odors are related to the shapes of chemical molecules

taste buds

receptor cells for taste

warning system

pain based on large nerve fibers; warns that bodily damage may be occurring

reminding system

pain based on small nerve fibers; reminds the brain that the body has been injured

gate control theory

a theory proposing that pain messages pass through neural “gates” in the spinal cord

multimodal integration

the process by which the brain combines information coming from multiple senses

selective attention

giving priority to a particular incoming sensory message

inattentional blindness

a failure to notice a stimulus because attention is focused elsewhere

change blindness

a failure to notice that the background is changing because attention is focused elsewhere

mind wandering

the process by which attention is withdrawn from the physical environment to focus on internal events

perception

selection, organization, and interpretation of sensory input

illusion

a misleading or misconstrued perception

hallucination

perception with no basis in reality

synesthesia

a perceptual phenomenon in which stimulation of one sensory system creates perceptual experiences in another sensory system

perceptual constructions

a mental model of external events

bottom up processing

organizing perceptions by beginning with low-level features

top down processing

perception guided by prior knowledge or expectations

figure ground organization

organizing a perception so that part of a stimulus appears to stand out as an object (figure) against a less prominent background (ground)

shape constancy

the principle that the perceived shape of an object is unaffected by changes in its retinal image

size constancy

the principle that the perceived size of an object remains constant, despire changes in its retinal image

brightness constancy

the principle that the apparent (or relative) brightness of objects remains the same so long as they are illuminated by the same amount of light

muller lyer illusion

two equal length lines tipped with inward or outward pointing vs appear to be of different lengths

depth perception

the ability to see three dimensional space and to judge distances accurately

depth cues

features of the environment and messages from the body that supply information about distance and space

binocular depth cues

perceptual features that impart information about distance and three dimensional space that require two eyes

retinal disparity

difference between the images projected onto each eye

stereoscopic vision

perception of space and depth as a result of each eye recieving different images

convergence

degree to which the eyes turn in to focus on an object

monocular depth cues

perceptual features that impart information about distance and three dimensional space that require just one eye

pictoral depth cues

monocular depth cues found in paintings, drawings, and photographs that impart information about space, depth and distance

virtual reality

environment in which sensory stimuli are provided by computer software to realistically simulate the real world

Consciousness

an organism’s awareness of its external environment and internal mental processes

Waking Consciousness

a state of clear, organized alertness`

Disorder of consciousness

a condition of awareness that is atypical (e.g. coma; persistent vegetative state)

Altered state of consciousness

a condition of awareness distinctly different in quality or pattern from waking consciousness

Hypnosis

state of consciousness characterized by focused attention, reduced peripheral awareness, and heightened suggestibility

hidden observer

a detached part of the hypnotized person’s awareness that silently watches events

basic suggestion effect

the tendency of hypnotized persons to carry out suggested actions as if they were involuntary

hypnotizability

one’s capacity for becoming hypnotized

meditation

mental exercise for producing relaxation or heightened awareness

mindfulness meditation

mental exercise based on widening attention to become aware of everything experienced at any given moment

concentrative meditation

mental exercise based on attending to a single object or thought

relaxation response

the pattern of internal bodily changes that occurs at times of relaxation

biological rhythm

any repeating cycle of biological activity, such as sleep and waking cycles or changes in body temperature

electroencephalograph (EEG)

device that records electrical activity in the brain

beta waves

small, fast brain waves associated with being awake and alert

alpha waves

large, slow brain waves associated with relaxation and falling asleep

sleep stages

levels of sleep identified by brain wave patterns and behavioral changes

rapid eye movement (REM)

swift eye movement during sleep

REM Sleep

stage of sleep marked by rapid eye movements, high frequency brain waves, and dreaming

non REM sleep (NREM)

Non rapid eye movement sleep characteristic of sleep stages 1,2,3, and 4

light sleep (stage 1 sleep)

marked by small irregular brain waves and some alpha waves

sleep spindles

distinctive bursts of brain wave activity that indicate a person is asleep