AP Psychology: Sensation and Perception

transduction

sensory messages/signals are transformed into neural impulses

sensory adaptation

decreasing responsiveness to stimuli due to constant stimulation (example: probably felt your socks when you put them on this morning, but stopped feeling them after a while)

sensory habituation

our perception of sensations is partially due to how focused we are on them

cocktail-party phenomenon

the ability to focus one’s attention on a single talker among a mixture of conversations and background noises

sensation

activation of our senses

perception

process of understanding and organizing these sensations; can be affected by your culture

cornea

a protective covering where light first enters the eye; helps focus the light

pupil

lets more or less light in

iris

the muscle that controls the pupil to either dilate or become smaller

lens

focuses the light that entered the pupil; curved and flexible

retina

the screen on the back of your eye; where all the receptors are; includes the cones and rods

cones

part of the retina that is responsible for color; concentrated towards the center of the retina

rods

part of the retina that is responsible for vision in low-light; respond to black and white; outnumber cones by 20:1; distributed throughout the retina; peripheral vision relies on rods

fovea

an indentation at the very center of the retina that contains the highest concentration of cones

blind spot

where the retina has no rods or cones

trichromatic theory

3 cones in a retina that detect blue, red, and green (primary colors of light)

opponent-process theory

the sensory receptors arranged in the retina come in pairs: red/green, yellow/blue, black/white

amplitude

the height of the wave and determines the loudness of the sound

frequency

the length of the wave and determines the pitch of the sound

high pitch —> high frequency (waves are densely packed)

low pitch —> low frequency (waves are spaced apart)

pinna

outer ear

ear canal

auditory canal; where the sound waves first travel down

eardrum

tympanic membrane; a thin membrane that vibrates as the sound waves hit it

ossicles

series of three small bones in the midear

hammer

malleus

anvil

incus

stirrup

stapes

oval window

where the vibration of the eardrum is transmitted to

cochlea

a structure shaped like a snail’s shell filled with fluid; when the oval window vibrates, the fluid moves; has vestibular sacs that helps with balance

basilar membrane

the floor of the cochlea

organ of Corti

neurons activated by the movement of hair cells; when the fluid of the cochlea moves, the hair cells move, and transduction occurs, firing the organ of Corti

place theory

hair cells in the cochlea respond to different frequencies of sound based on where they are located in the cochlea

frequency theory

we sense pitch because the hair cells fire at different rates (frequencies) in the cochlea

conduction deafness

when something goes wrong with the system of conducting the sound to the cochlea; hearing aids can help

nerve / sensorineural deafness

when the hair cells are damaged, usually by loud noise; hair cells do not regenerate, making it harder to treat

gate-control theory

explains that some pain messages have a higher priority than others; a “gate” swings open for high priority messages and shuts for low priority messages (won’t feel the pain)

papillae

where taste buds are located on; the bumps you see on your tongue

olfactory bulb

gathers the messages from the olfactory receptor cells and sends information to the brain

sense of smell

goes directly to the amygdala and hippocampus; may explain why smell is such a powerful trigger for memories

vestibular sense

tells us about how our body is orientated in space

kinesthetic sense

gives us feedback about the position and orientation of specific body parts

absolute threshold

the minimum amount of stimulus needed to detect something

difference threshold 

aka just-noticeable difference; the minimum amount of change needed in a stimulus before we detect a change

Weber’s law

principle that two stimuli must differ by a constant minimum percentage (abt 2%; difference threshold)

signal detection theory

predicts how and when we detect the presence of a faint stimulus amid background stimulation

top-down processing

using prior experiences for perception; example (using background knowledge to perceive the random shapes of clouds as organized shapes)

perceptual set

a predisposition to perceiving something in a certain way

bottom-up processing

only use the features of the object to build a complete perception

figure-ground

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

size and shape constancy

we know that the size and shape of an object does not change even when our retinas produce different images

stroboscopic effect

an effect used in movies or flip books where images in a series of still pictures are presented at a certain speed to appear to be moving

phi phenomenon

a series of lights turned on and off at a particular rate will appear to be one moving light

visual cliff experiment

used to detect depth perception

monocular cues

depth cues that do not depend on having two eyes

binocular cues

need two eyes to pick cues up

binocular (retinal) disparity

two retinas are taking in two different things

convergence

when an object gets closer to our face, our eyes come together to keep focus on the object

semi-circular canal

fluid that helps with balance

synesthesia

when two or more sensations compete/collide (ex: Science - Yellow)