AP Psychology Unit 4

sensation

sensation

the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment. (Myers Psychology for AP 3e p. 158)

sensory receptors

sensory nerve endings that respond to stimuli. (Myers Psychology for AP 3e p. 158)

perception

the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events. (Myers Psychology for AP 3e p. 158)

bottom-up processing

analysis that begins with the sensory receptors and works up to the brain's integration of sensory information. (Myers Psychology for AP 3e p. 158)

top-down processing

information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations. (Myers Psychology for AP 3e p. 158)

selective attention

the focusing of conscious awareness on a particular stimulus. (Myers Psychology for AP 3e p. 158)

inattentional blindness

failing to see visible objects when our attention is directed elsewhere. (Myers Psychology for AP 3e p. 160)

change blindness

failing to notice changes in the environment; a form of inattentional blindness. (Myers Psychology for AP 3e p. 161)

transduction

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 brain can interpret. (Myers Psychology for AP 3e p. 162)

psychophysics

the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them. (Myers Psychology for AP 3e p. 162)

absolute

threshold the minimum stimulus energy needed to detect a particular stimulus 50 percent of the time. (Myers Psychology for AP 3e p. 163)

signal detection theory

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 experience, expectations, motivation, and alertness. (Myers Psychology for AP 3e p. 163)

subliminal

below one's absolute threshold for conscious awareness. (Myers Psychology for AP 3e p. 163)

difference threshold

the minimum difference between two stimuli required for detection 50 percent of the time. We experience the difference threshold as a just noticeable difference (or jnd). (Myers Psychology for AP 3e p. 163)

priming

the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response. (Myers Psychology for AP 3e pp. 165, 345)

Weber's law

the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount). (Myers Psychology for AP 3e p. 165)

sensory adaptation

diminished sensitivity as a consequence of constant stimulation. (Myers Psychology for AP 3e p. 165)

perceptual set

a mental predisposition to perceive one thing and not another. (Myers Psychology for AP 3e p. 169)

extrasensory perception (ESP)

the controversial claim that perception can occur apart from sensory input; includes telepathy, clairvoyance, and precognition. (Myers Psychology for AP 3e p. 172)

parapsychology

the study of paranormal phenomena, including ESP and psychokinesis. (Myers Psychology for AP 3e p. 172)

wavelength

the distance from the peak of one light or sound wave to the peak of the next. Electromagnetic wavelengths vary from the short blips of gamma rays to the long pulses of radio transmission. (Myers Psychology for AP 3e p. 177)

hue

the dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so forth. (Myers Psychology for AP 3e p. 177)

intensity

the amount of energy in a light wave or sound wave, which influences what we perceive as brightness or loudness. Intensity is determined by the wave's amplitude (height). (Myers Psychology for AP 3e p. 177)

cornea

the eye's clear, protective outer layer, covering the pupil and iris. (Myers Psychology for AP 3e p. 177)

pupil

the adjustable opening in the center of the eye through which light enters. (Myers Psychology for AP 3e p. 177)

iris

a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening. (Myers Psychology for AP 3e p. 177)

lens

the transparent structure behind the pupil that changes shape to help focus images on the retina. (Myers Psychology for AP 3e p. 177)

retina

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. (Myers Psychology for AP 3e p. 177)

accommodation

(1) in sensation and perception, the process by which the eye's lens changes shape to focus near or far objects on the retina. (2) in developmental psychology, adapting our current understandings (schemas) to incorporate new information. (Myers Psychology for AP 3e pp. 177, 498)

rods

retinal receptors that detect black, white, and gray, and are sensitive to movement; necessary for peripheral and twilight vision, when cones don't respond. (Myers Psychology for AP 3e p. 178)

cones

retinal receptors that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. Cones detect fine detail and give rise to color sensations. (Myers Psychology for AP 3e p. 178)

optic nerve

the nerve that carries neural impulses from the eye to the brain. (Myers Psychology for AP 3e p. 178)

blind spot

the point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there. (Myers Psychology for AP 3e p. 179)

fovea

the central focal point in the retina, around which the eye's cones cluster. (Myers Psychology for AP 3e p. 179)

Young-Helmholtz trichromatic (three-color) theory

the theory that the retina contains three different types of 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. (Myers Psychology for AP 3e p. 181)

opponent-process theory

the theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green. (Myers Psychology for AP 3e p. 182)

feature detectors

nerve cells in the brain's visual cortex that respond to specific features of the stimulus, such as shape, angle, or movement. (Myers Psychology for AP 3e p. 183)

parallel processing

processing many aspects of a problem simultaneously; the brain's natural mode of information processing for many functions. (Myers Psychology for AP 3e pp. 126, 183, 329)

gestalt

an organized whole. Gestalt psychologists emphasized our tendency to integrate pieces of information into meaningful wholes. (Myers Psychology for AP 3e p. 187)

figure-ground

the organization of the visual field into objects (the figures) that stand out from their surroundings (the ground). (Myers Psychology for AP 3e p. 187)

grouping

the perceptual tendency to organize stimuli into coherent groups. (Myers Psychology for AP 3e p. 188)

depth perception

the ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance. (Myers Psychology for AP 3e p. 189)

visual cliff

a laboratory device for testing depth perception in infants and young animals. (Myers Psychology for AP 3e p. 189)

binocular cue

a depth cue, such as retinal disparity, that depends on the use of two eyes. (Myers Psychology for AP 3e p. 189)

retinal disparity

a binocular cue for perceiving depth. By comparing retinal images from the two eyes, the brain computes distance—the greater the disparity (difference) between the two images, the closer the object. (Myers Psychology for AP 3e p. 189)

monocular cue

a depth cue, such as interposition or linear perspective, available to either eye alone. (Myers Psychology for AP 3e p. 190)

phi phenomenon

an illusion of movement created when two or more adjacent lights blink on and off in quick succession. (Myers Psychology for AP 3e p. 190)

perceptual constancy

perceiving objects as unchanging (having consistent color, brightness, shape, and size) even as illumination and retinal images change. (Myers Psychology for AP 3e p. 191)

color constancy

perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object. (Myers Psychology for AP 3e p. 192)

perceptual adaptation

the ability to adjust to changed sensory input, including an artificially displaced or even inverted visual field. (Myers Psychology for AP 3e p. 195)

audition

the sense or act of hearing. (Myers Psychology for AP 3e p. 198)

frequency

the number of complete wavelengths that pass a point in a given time (for example, per second). (Myers Psychology for AP 3e p. 198)

pitch

a tone's experienced highness or lowness; depends on frequency. (Myers Psychology for AP 3e p. 198)

middle ear

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. (Myers Psychology for AP 3e p. 199)

cochlea

a coiled, bony, fluid-filled tube in the inner ear; sound waves traveling through the cochlear fluid trigger nerve impulses. (Myers Psychology for AP 3e p. 199)

inner ear

the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs. (Myers Psychology for AP 3e p. 199)

sensorineural hearing loss

hearing loss caused by damage to the cochlea's receptor cells or to the auditory nerves; the most common form of hearing loss, also called nerve deafness. (Myers Psychology for AP 3e p. 200)

conduction hearing loss

a less common form of hearing loss, caused by damage to the mechanical system that conducts sound waves to the cochlea. (Myers Psychology for AP 3e p. 200)

cochlear implant

a device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea. (Myers Psychology for AP 3e p. 201)

place theory

in hearing, the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated. (Myers Psychology for AP 3e p. 202)

frequency theory

in hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch. (Also called temporal theory.) (Myers Psychology for AP 3e p. 202)

gate-control theory

the theory that the spinal cord contains a neurological "gate" that blocks pain 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. (Myers Psychology for AP 3e p. 207)

olfaction

the sense of smell. (Myers Psychology for AP 3e p. 211)

kinesthesia

our movement sense—our system for sensing the position and movement of individual body arts. (Myers Psychology for AP 3e p. 213)

vestibular sense

our sense of body movement and position that enables our sense of balance. (Myers Psychology for AP 3e p. 213)

embodied cognition

the influence of bodily sensations, gestures, and other states on cognitive preferences and judgments. (Myers Psychology for AP 3e p. 214)

sensory interaction

the principle that one sense may influence another, as when the smell of food influences its taste. (Myers Psychology for AP 3e p. 214)