AP Psychology Unit 3 Vocabulary

sensation

the physical process by which our sensory receptors and nervous system receive stimuli (sense of smell/taste/audition/etc.)

perception

the psychological process of organizing and interpreting sensory information.

Transduction

The conversion of sensation signals into a neurological signal that can be perceptually understood (the bridge between sensation and perception).

bottom-up processing

analysis that begins with the sensory receptors and works up to the brain for understanding.

top-down processing

analysis of stimuli that begins with the brain (already have an idea of what something is supposed to be), which allows our sensory organs to better detect what we are sensing.

inattentional blindness

failing to see visible objects when our attention is directed elsewhere. (Example - Moonwalking Bear)

change blindness

failing to notice changes in the environment. (Example - Person Swap)

absolute threshold

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

signal detection theory

a theory that our ability to perceive stimuli depends partly on a person's experience, expectations, motivation, and alertness.

subliminal perception

the registration of sensory input without conscious awareness (below our absolute threshold)

difference threshold

the minimum difference between two stimuli required for detection 50 percent of the time. Also called the just noticeable difference (jnd).

Weber's law

the principle that, to be perceived as different, two stimuli must differ by a constant percentage (rather than a constant amount). Example - noticing 5 grams of sugar in water with only 1 gram of sugar to start is easier than noticing 5 grams of sugar in something with 40 grams of sugar already.

sensory adaptation

diminished sensitivity as a consequence of constant stimulation. No longer noticing a smell in a room for example.

wavelength

the distance from the peak of one light or sound wave to the peak of the next. = The hue/color we perceive. Red = long, Blue = short

Amplitude

Height of a visible light wave = how bright the color is.

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 (by the fovea) and perceive COLOR. Function in daylight or in well-lit conditions.

optic nerve

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

blind spot

the point at which the optic nerve meets the retina = no cones/rods

fovea

the central focal point in the retina, around which the eye's cones cluster = greatest acuity of vision

Young-Helmholtz trichromatic (three-color) theory

the theory that the retina contains three different 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.

Opponent-process theory

the theory that opposing retinal processes (red-green, yellow-blue, 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. Helps explain negative after-image effects.

feature detectors

nerve cells in the occipital lobe of the brain that respond to specific features of the stimulus, such as shape, angle, or movement (discovered by Hubel and Wiesel)

audition

the sense or act of hearing.

amplitude of sound wave

the height of a wave - determines loudness of a sound

frequency of sound

the number of vibrations per second - determines the pitch of sound

middle ear

the chamber between the eardrum and cochlea containing three tiny bones (ossicles) - hammer, anvil, and stirrup - that concentrate the vibrations of the eardrum

cochlea

a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses. Inside is the Basilar Membrane and Hair Cells.

hair cells

specialized auditory receptor neurons inside the cochlea on the basilar membrane

inner ear

the innermost part of the ear, containing the cochlea, semicircular canals (balance) and auditory nerve.

cochlear implant

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

conduction deafness

An inability to hear resulting from damage to the ossicles or eardrum

nerve deafness

Hearing loss created by damage to the hair cells or the auditory nerve fibers in the inner ear.

kinesthetic sense

sense of the location of body parts - your "body sense"

vestibular sense

the sense of sense of balance - found in the inner ear (semicircular canals).

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.

Gestalt Psychology

a psychological approach that emphasizes that we often perceive the whole rather than the sum of the parts (Closure/Proximity/Figure-ground, etc.)

Gestalt Principles

closure, continuity, similarity, proximity, and figure & ground

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.

binocular cues

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 distance—the greater the disparity (difference) between the two images, the closer the object.

monocular cues

depth cues that you only need 1 eye for such as interposition, linear perspective, texture gradient, and relative size.

linear perspective

A monocular cue for perceiving depth; the more parallel lines converge, the greater their perceived distance.

relative size

a monocular cue for perceiving depth; the smaller something appears, the further it is away

Interposition

monocular visual cue in which two objects are in the same line of vision and one blocks another object = object blocked is further away

texture gradient

a monocular cue for perceiving depth; the closer an object the more texture detail we can perceive.

perceptual constancy

perceiving objects as unchanging (having consistent shapes, size, lightness, and color) even as illumination and retinal images change.

Olfaction

sense of smell

olfactory bulb

a brain structure located above the nasal cavity beneath the frontal lobes

Gustation

sense of taste (sweet, sour, salty, bitter, and umami)

olfactory receptor neurons

sensory receptor cells that convert chemical signals from odorants into neural impulses that travel to the brain

place theory of hearing

the theory that different areas of the basilar membrane respond to different frequencies

frequency theory of hearing

the theory that the entire basilar membrane acts like a microphone, vibrating as a whole in response to a sound - rate of frequency determines what we hear

stroboscopic movement

a type of apparent movement based on the rapid succession of still images, as in motion pictures

phi phenomenon

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

sensory interaction

when one sense influences another, as when the smell of food influences its taste

embodied cognition

the mutual influence of bodily sensations on the way we think or feel.

Synesthesia

when one kind of sensory stimulus evokes the subjective experience of another - like sounds producing the sense of colors