AP Psychology: Unit 3

sensation

sensation

raw data that comes from the 5 senses and sensory receptors

perception

processes sensation

figure and ground

Gestalt principle; the tendency of the visual system to place some objects into focus and leave others in the background

continuation

Gestalt principle; the tendency to view objects in smooth patterns

closure

Gestalt principle; the tendency of the brain to subconsciously fill in missing information when looking at familiar objects

similarity

Gestalt principle; the tendency to perceive objects with similar characteristics as whole instead of separately

proximity

Gestalt principle; the tendency of objects that are close together to appear as a single object

symmetry

Gestalt principle; the tendency for symmetrical objects to appear as a single object

depth perception

the ability to perceive relative distance in the visual field

binocular cue

requires both eyes

monocular cue

requires a single eye

sensory transduction

the process by which an outside stimulus activates sensory receptors, therefore changing them into electrical signals and sending them to the brain

absolute threshold

minimum amount of stimulus needed to notice something

difference threshold

the minimum amount of change needed between multiple stimuli in order to recognize a difference

Weber-Fechner Law

the mathematical formula that expresses the concept of difference threshold by explaining that it depends on the proportion of sensation and intensity of stimulus; the stimulus should differ by a constant percent rather than an amount

sensory adaptation

when a stimulus is prolonged to the point where our bodies are no longer as responsive to it

habituation

when a repeated stimulus causes decreased effectiveness

size constancy

when objects are perceived as the same size

color constancy

when the perception of color remains the same under different lighting

shape constancy

when the shape of an object is perceived to be the same during movement

lightness constancy

the perception of black/white/grey within objects

schema

the collection of basic knowledge that guides the perception of a situation

sclera

the outside layer of white fibrous tissue that forms the substance of the eye

cornea

the transparent outer layer on the front of the eye that bends light

aqueous humor

maintains pressure within the eye and provides nourishment

iris

the colored muscle that controls how much light enters the eye

pupil

inside the iris and allows light to pass through

lens

located behind the pupil; changes the focus of the eye; curved on both sides

vitreous humor

gel-like fluid in the vitreous cavity that supports the eye and gives it shape

retina

light-sensitive cells located at the back of the eye that convert light into neural impulses

optic nerve

sends impulses from the retina to the thalamus

fovea

the point of central focus that light is directed to by the lens

choroid

provides the eye with oxygen and nutrients derived from blood vessels

astigmatism

occurs when the cornea has an irregular shape

cataracts

occurs when the lens is cloudy

rods

located on the outer edge of the retina; responsible for unclear vision at low light levels

cones

located at the small depression of the eye; responsible for colored vision at high light levels

trichromatic theory

suggests that we see color because different wavelengths of light stimulate combinations of primary color receptors

opponent processing theory

suggests that there are opposing color receptors in the brain (e.g. red-green, blue-yellow, black-white), therefore explaining things such as afterimages and color blindness

achromatism

a form of color blindness where an individual lacks cones and can only see in black/white

dichromatism

a form of color blindness where an individual is missing 1 out of the 3 cone pigments

trichromatism

normal color vision

synesthesia

when the stimulation of a single sense also stimulates another sense at the same time

top-down processing

when one uses prior knowledge to interpret information

proofreaders’ illusion

when one misses errors in perception because they’re aware of their own intentions

bottom-up processing

when information is interpreted as is but in simpler terms

pinna

outer cartilage of ear; directs sound into the ear canal

external auditory canal

the tube entrance to the ear that directs sound to the tympanic membrane

tympanic membrane (eardrum)

separates the outer ear from the middle ear; creates vibrations when it receives sound waves which are then transferred into mechanical vibrations and directed to the tiny bones in the middle ear

ossicles

small bones in the middle ear that connect the tympanic membrane to the inner ear; allows for the transmission and amplification of sound waves

malleus

hammer ossicle

incus

anvil ossicle

stapes

stirrup ossicle

oval window

the opening in the cochlea wall; amplifies sound and sends it to the inner ear

Organ of Corti

located on the basilar membrane; sensory receptors that help with hearing

stereocilia

tiny hair cells that protrude from the Organ of Corti

basilar membrane

vibrates and moves stereocilia; beginning of conversion to electrical impulses

semicircular canals

located above the cochlea; filled with liquid and maintains balance

place theory

suggests that the placement of stereocilia on areas of the basilar membrane result in the brain being able to interpret sound pitch

frequency

determines pitch (shorter sound waves = higher pitch)

amplitude

determines the strength of sound waves

sensorineural hearing loss

results from damage to the cilia or auditory nerve

conductive hearing loss

results from something blocking sound from moving through the outer ear to the middle and inner parts of the ear