AP Psych Sensations & Perceptions

Bottom-up Processing

Use only the features of an object to build a perception; analysis that begins with the sensory receptors and works up to the brain's integration of sensory

Top-Down Processing

use background knowlege to fill in the gaps and create a perception; info processing guided by higher level mental processes

Perceptual sets

tendency to perceive something in a certain way; influenced by schema and recent experiences

Signal Detection Theory

detection of a stimulus depends on the intensity of the stimulus and the physical & psychological state of the individual

False Positive

think we perceive something not there

False Negative

do not perceive something that is there

Just Noticeable Difference

minimum difference b/w 2 stimuli required for detection 50% of the time

Sensory adaptation

diminished sensitivity as a consequence of constant stimulation

Absolute threshold

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

Eye Wavelength

affects color

Eye amplitude

affects brightness

Transduction

transformation of energy into a neural impulse

Retina

where transduction occurs; the inner layer, receives image upside down & contains receptor cells

Rods

located throughout retina; outnumber cones; black & white receptors

Cones

located in center of retina; visual color receptors; work best in well lit conditions

Feature Detectors

neurons that respond to different edges, lines, or movements

Color Blindness

inability to see certain color combinations: red-green or blue-yellow

Monochromatic

individuals who only see shades of gray

Dichromatic

people who only see two of the three primary colors; blind to red-green or blue-yellow; colorblind

Trichromatic Theory

color vision based on additive color mixing; suggest that the retina contains three types of color receprots, cones: red, green, blue

Opponent-Process Theory

used to explain after images; suggest that the retina contains three pairs of color receptors: yellow-blue, red-gree, black-white; pairs work in oposition

Cochlea

where transduction occurs in the ear

Ear wavelength

affects pitch

Ear amplitude

affects loudness

Place Theory

diff sound waves, trigger hair cells in diff. areas of cochlea; explains high pitched sounds better than low

Frequency Theory

the rate at which hair cells vibrate depends on frequency; vibrating hair cells trigger neural impulses that fire at the same rate; best explains low pitched sounds

Sensorinueral deafness

problem w/in cochlea, hair cells damaged, won't regenerate, cochlear implant

Conduction deafness

problem before cochlea, can't conduct vibrations-ear drum punctured, bones in middle ear don't vibrate; hearing aids can help

Sensation

picking up physical energy from environment

Perception

how we organize info from senses; creating something meaningful from raw sensory info

Subliminal Messages

imperceptable to the conscious but perceived by subconcious; below the threshold-dectable low % of time

Cornea

protective covering; helps focus

pupil

dilates or compresses

iris

muscles that dilate or close pupil

lens

focuses light

optic nerve

sends impulses to thalamus; then to visual cortex in the occipital lobe

blind spot

where optic nerve leaves retina, no rods or cones

Thalamus

where optic nerve sends impulses to

Afterimages

imague (usually contrasting color) that persists after stimulation is gone

Outer ear

ear canal, eardrum

middle ear

hammer, anvil, stirrup

inner ear

oval window, cochlea, basilar membrane

Sensory interaction between tast and smell

smeel adds to our perception of taste, can change it; smell plus texture plus taste equals flavor; principle that 1 sense may influence another

Olfactory receptors and bulbs

receptor cells linked to the olfactory bulb which gathers the messages from the receptor cells and sends this info to the brain

Olfactory bulb connects to what parts of brain

amygdala, hippocampus (limbic system)

Vestibular Sense (responsible for...)

awareness of where our body is in space

semicircular canals

in the inner ear, give the brain feedback about body orientation, partially filled with fluid

Kinesthetic sense (controls...)

awareness of where our body parts are

taste

gustation

smell

olfaction

touch

tactile

Gate Control Theory

theaory that the spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass to the brain

Selective Attention

ability to focus awareness on a single thing and ignore other things

Cocktail Party Effect

phenomenon of selective attention in speech perception; ability to attend to only 1 voice among many

Figure Ground

figuring out what's in the background and whats in the foreground (figure & background)

Proximity

objects that are aclose together are perceived as belonging to the same group

Similarity

objects similar in appearnace are grouped together

Continuity

objects that form continuous, smooth patterns are more likely to be perceive as belonging to the same group

closure

objects that make up a recognizable image are libkely to be perceived as belonging to same group (fill int he gaps to make whole)

Visual Cliff Experiment

put baby on ledge with glass & see if it will crawl past the ledge tot he mom

Retinal Disparity

diffeence between the image each eye receives; brain gets both & uses to calculate distance/depth
Closer object = large disparity
distant object = small

Convergence

our eyes turn in or convverge different degrees depending on how far/close something is
Closer= converge more
Distant = converge less

Relative size

if we know 2 objects are similar size, perceive on that casts smaller retinal image as farther away

Interposition

if one objcet blocks view of another, perceive it as closer

Texture gradient

if we can see greater detail, peceive it as closer

Linear perspective

parallel lines appear to converge in distance, more they converge the greater the distance we perceive

shadowing

nearby objects reflect more light to our eyes, so perceive dimmer as farther

Phi Phenomenon

lightbulbs turned on & off at particular rate give appearance of motion

Stroboscopic Effect

presenting images at certain speed will give off appearance of motion

Size constancy

closer object, larger image on retina, but we know that distance is sense for change, keep constant size in mind, know it doesn't shrink or grow

shape

viewing objects from different angles produces different shapes on our retina

Lightness/Brightness

perceive constant color, even when light reflected off changes

Muller-Lyer Illusion

our experience with corners of rooms & buildings prompts us to interpret inverted lines as farther away and therefore longer

Ames Room

brain assumes walls are parallel, one corner twice as far away

Culture influences perception

research shows, rules psycholgists thought were innate are actually learned

Visual Capture

tendency for vision to dominate other senses

Human Factor Analysis/Psychology

design appliances, machines, and work settings that fit our natural perceptions