Unit 3 Ap Psych

sensation

sensation

the process by which our sensory receptors (eyes, ears, skin) and nervous system receive and represent stimulus energies from environment

stimulus

anything that you’re taking in

bottom-up processing

analysis that begins with sensory receptors and works up to the brain’s integration of sensory information

perception

process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events

top-down processing

information processing guided by prior experiences, ideas, and expectations, working down to interpret sensations

transduction

converting one form of energy into another that our brain can use (ex: light and sound waves converted to sight and hearing)

absolute threshold

refers to the minimum level of stimulus intensity needed to detect a stimulus half the time, anything below the threshold is “subliminal”

priming

the activation, often unconsciously, of certain associations, thus predisposing pone’s perception, memory, or response

subliminal messages

below one’s absolute threshold for conscious awareness

difference threshold

the minimum difference between two stimuli (weight, temperature) for a person to detect the difference half the time

Weber's law

different thresholds increase with the magnitude of the stimulus half the time (ex:50 degrees to 60 is a big diff vs 1000 degrees to 1010 degrees), size of difference threshold is greater for heavier objects than lighter ones

sensory adaptation

diminished sensitivity to stimuli as result of constant stimulation, bad smells or loud noise

perceptual set

mental predisposition to perceive one thing and not another

*psychophysics

objective stimuli (exact temperature, decimals etc) is subjective among individuals’ perception (psychological influence on the physical world) physical characteristics of stimuli and our psychological experience of them

signal detection theory

our thresholds vary constantly depending on emotions, distractions, motivation, expectations etc

wavelength

hue (long wavelength = low frequency, short wavelength = high frequency) - distance between two wave crests

amplitude

height, intensity/brightness

cornea

protects eye/bends light

pupil

small adjustable opening

iris

colored muscle that dilates/constricts in response to light intensity - regulates amount of light entering eye

lens

focuses light rays into an image on fovea in back of eyeball, can change curvature to focus

accommodation

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

retina

blood vessel tissue on eyeball’s inner surface

rods and cones

light energy chemical changes on retina’s receptor cells

fovea

the image you’re looking at upside down, not on the eye

bipolar cells/ganglion cells

type of neuron located near the inner surface of the retina of the eye, receives visual information from photoreceptors via bipolar cells

optic nerve

ganglion cell axons twisted together, carries neural impulses from eye to brain

blindspot/optic disc

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

feature detectors

neurons in visual cortex that respond to specific features of a visual stimulus (angles, edges, lines) - consist of nerve cells in brain

parallel processing

sensory details are processed in separate areas of the brain that combine to form an image (color, motion, form, depth)

*Young-Helmholtz trichromatic (three-color) theory

there are three types of color receptor cones in eye (red, blue, green), all colors are stimulated combinations of these cones

*opponent-process theory

cones compete (red v green, blue v yellow, black v white) and color vision is the result, explains why we can’t see “reddish green” or “yellowish blue” and why we see after images

after images

overwhelm cones with one color that the other one doesn’t come through to the surface until it goes away, something left over that wasn’t there before

stroop effect

our tendency to experience difficulty naming a physical color when it is used to spell the name of a different color

color blindness

people with missing rods or cones, gene mutations, or eye damage may have color blindness, inability to discriminate between colors and to perceive color hues

gestalt

german word for “form” or “whole”, early study of visual organization, we organize clusters of sensations into meaningful patterns that make sense to us

figure/ground

perceive objects (figure) as separate from their surroundings (the background), some images give us an ambiguous option without a clear figure or ground

grouping

organize stimuli/figures into meaningful forms

proximity

we group nearby figures together

continuity

we perceive continuous patterns rather than separated ones

closure

we fill in gaps to create a whole object, perceive disconnected parts as a whole

similarity

we group things that are similar

depth perception

ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allow us to judge distance

binocular disparity

brain uses both eyes to judge distance, the greater the disparity (difference) between the two objects, the closer the object

monocular cues

we can judge depth in two dimensional images like photos/paintings/screens by only using one eye

relative size

we see familiar objects (of known size) as farther away when they appear smaller

interposition

partially covered objects appear further away

relative height

we tend to perceive the higher part of a scene as farther away

relative motion

when we are moving, we can tell which objects are farther away because it takes longer to pass them (closer moves faster, farther is smaller - ex: clouds and moon)

linear perspective

the convergence of parallel lines indicates greater distance, two lines meet the retina as being the same size, however, our perception of distance affects our perception of length

light and shadow

highlights and shadows can provide information about an objects dimension and depth, because visual system assumes the light comes from above, a totally different perception is obtained if this image is viewed upside down

visual cliff

babies are inborn with depth perceptions

perceptual constancy

enables us to see an object as unchanging even as illumination and retinal images change (example of top down processing)

color constancy

we perceive familiar objects as having consistent color/shade, even if the color is actually different

brightness constancy

the tendency to perceive a familiar object as having the same brightness under different conditions of illumination

relative luminance

amount of light an object reflects relative to its surroundings

shape constancy

the perception of the shape of a given object remains constant despite changes in the shape of the object's retinal image

size constancy

the result of cognitive scaling operations that enable us to perceive an object as having the same size when presented at different viewing distances

Ames room

1934 room designed to manipulate our size constancy

moon illusion

moon seems larger on the horizon than in the sky

restored vision

people born blind and gain sight later in life

perceptual adaptation

humans can adapt and their brains can adjust their perception, artificially displaced or inverted visual field

audition

hearing

amplitude

loudness/volume of sounds - height of soundwave

frequency

pitch - length of soundwave

decibels

measure sound, ​​logarithmic unit used to measure sound level

eardrum

separates the outer ear from the middle ear, membrane vibrates when sound waves strike it converting the sound wave into a nerve impulse that travels to the brain

middle ear (the ham­mer, anvil, and stirrup)

chamber between eardrum and cochlea containing three tiny bones that concentrate the vibrations of the eardrum on the cochlea’s oval window

cochlea (in inner ear)

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

basilar membrane

main mechanical element of the inner ear, vibrates in the cochlea

hair cells

sensory receptors in ear, loudness is determined by the number of activated hair cells in the cochlea

conduction hearing loss

problems with outer/middle ear not conducting sound well to cochlea, can be treated with hearing aids, common cause is ear infections

sensorineural hearing loss

cochlea’s hair cell receptors (inner ear)/ nerve damage can cause this more common form of hearing loss, can be caused by disease, aging, exposure to loud noise

cochlear implant

can restore hearing for nerve deafness, converts sounds into electrical signals

place theory

perception of pitch is associated with vibration of different proportions of cochlea, where basilar membrane is stimulated

frequency theory

perception of pitch is associated with the frequency at which the entire basilar membrane vibrates

senses of touch

pressure, warmth, cold, and pain

pain

body’s way of telling you something has gone wrong

nociceptors

sensory receptors that detect hurtful temperatures, pressures, or chemicals

mechanoreceptors

sense pressure, texture, vibrations

thermoreceptors

sense temperature

gate-control theory

spinal cord has a “gate” that either blocks pain signals from small nerve fibers or allows them to pass to brain

phantom limb sensations

brain creates pain after a limb amputation, brain is misinterpreting sensory input

hypnosis

social interaction where a hypnotist suggests to a subject that certain perceptions, feelings thoughts, or behaviors will spontaneously occur

posthypnotic suggestions

suggestion made during a hypnosis session to be carried out after the subject is no longer hypnotized, helped reduce headaches, asthma, obesity but doesn’t help with addiction

social influence theory

patients may be acting the role of a “good hypnotic subject”, influenced by hypnotist/crowd

divided-consciousness theory of hypnosis

dissociation, proposes that hypnosis is a special dual-processing state where an individual is split between different levels of consciousness

selective attention

may also play a role in hyp­notic pain relief - increases activity in frontal lobe attention systems

taste sensations

sweet, sour, salty, bitter and umami

sensory interaction

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

smell (olfaction) process

receptors smells in nasal passage go to the olfactory bulb and skip the thalamus to the limbic system and temporal lobe. Limbic system triggers memories and emotions (hippocampus)

embodied congition

brain circuits that process sensations connect with those responsible for cognition (thinking) - perception changes the way you think (holding a warm cup of tea rather than a cold one makes us nicer)

*kinesthesis

how we coordinate movement without having to constantly watch our movements

vestibular sense

chambers in our ear have hair like receptors that send messages to cerebellum to help us balance

semicircular canals

three tiny, fluid-filled tubes in your inner ear that help you keep your balance

vestibular sacs

respond to balance and encode information about the head's orientation.

retinal disparity

distance between or right and left eyes functions to provide us with a cue for depth perception