AP Psychology Unit IV

sensation

the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment

perception

the process of organizing and interpreting sensory information, past experiences affect this

bottom-up

looking at all of the individual parts that make up what you're seeing, ex. size, shape, color

top-down

looking at something as a whole and applying it to stuff you already know

selective attention

the focusing of conscious awareness on a particular stimulus

inattentional blindness

failing to see visual objects when our attention is directed elsewhere

change blindness

failing to notice changes in the environment

transduction

conversion of one form of energy into another
ex. changing color waves into neural messages

psychophysics

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

absolute threshold

the minimum stimulus needed to detect a particular stimulus 50% of the time

signal detection theory

a theory predicting how and when we detect the presence of a faint stimulus amid background stimulation/noise. Assumes that there is no single absolute threshold and that detection depends partly on a person's experience, expectations, motivation, and alertness

subliminal

below one's absolute threshold for conscious awareness

priming

the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response
ex. quickly flashing a happy or sad photo before asking about a perception of a certain thing

difference threshold

the minimum difference between the two stimuli required for detection 50% of the time, we experience this as "just noticeable difference"

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)

8 percent

According to Weber's law, what percent would two lights have to differ for an average person to perceive a difference?

2 percent

According to Weber's law, what percent would two objects have to differ for an average person to perceive a difference?

0.3 percent

According to Weber's law, what percent in frequency would two tones have to differ for an average person to perceive a difference?

sensory adaptation

diminished sensitivity as a consequence of constant stimulation

perceptual set

a mental predisposition to perceive one thing and not another

ESP

extrasensory perception

wavelength

the distance from the peak of one light or sound wave to the peak of the next

hue

the dimension of color that is determined by the wavelength of light

intensity

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

short wavelength

high frequency, bluish colors, high-pitched sounds

long wavelength

low frequency, reddish colors, low-pitched sounds

great amplitude

bright colors, loud sounds

small amplitude

dull colors, quiet sounds

pupil

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

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

lens

the transparent structure behind the pupil that changes shape to help focus images on the retina

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

accomodation

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

rods

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

cones

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

optic nerve

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

blind spot

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

fovea

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

feature detectors

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

parallel processing

the processing of many aspects of a problem simultaneously; the brain's natural mode of information processing for many functions, including vision

Young-Helmholtz trimatic (three-color) processing theory

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

opponent-process theory

the theory that opposing retinal processes enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated ny red and inhibited by green

opponents in opponent-process theory

red-green, yellow-blue, white-black

gestalt

an organized whole, these psychologists emphasized our tendencies to integrate separate pieces of information into meaningful wholes

figure-ground

the organization of the visual field into objects that stand out from their surroundings

grouping

the perceptual tendency to organize stimuli into coherent groups

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

visual cliff

a laboratory device for testing depth perception in infants and young animals

binocular clues

depth cues, such as retinal disparity, that depend on the use of two eyes

retinal disparity

a binocular cue for perceiving depth: by comparing images from the retinas in the two eyes, the brain computes the distance

monocular cues

depth cues, such as interposition and linear perspective, available in either eye alone

phi phenomenon

an illusion of movement created when two or more adjacent lights blink on and off in quick succession

perceptual constancy

perceiving objects as unchanging (having consistent shapes, sizes, brightness, and color) even as illumination and retinal images change

color constancy

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

perceptual adaptation

in vision, the ability to adjust to an artificially displaced or even inverted visual field

audition

the sense or act of hearing

frequency

the number of complete wavelengths that pass a point in a given time

pitch

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

middle ear

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

cochlea

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

inner ear

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

sensorineural hearing loss

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

conduction hearing loss

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

cochlear implant

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

place theory

in hearing, the theory that links the pitch we hear with the place where the cochleas' membrane is stimulated, best explains how we sense high pitches

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, best explains how we sense low pitches

cilia

a short microscopic hairlike vibrating structure, about 16,000 of them in the cochlea, this triggers a neural response

85

prolonged exposure about ____ decibels produces hearing loss.

volley principle

best explains how we sense intermediate pitches

pressure, warmth, cold, pain

basic 4 skin sensations

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

kinesthesia

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

vestibular sense

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

sensory interaction

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

embodied cognition

in psychological science, the influence of bodily sensations, gestures, and other states on cognitive preferences and judgments

nociceptors

sensory receptors that detect hurtful temperatures, pressure, or chemicals

sensory interaction

the principle that one sense may influence another