ap psychology: sensation & perception unit

what do sensory organs do?

detect stimuli

sensory organs

• eyesight

• gustation (sense of taste)

• olfaction (sense of smell)

• hearing

• touch

sensation is…?

mostly biological

perception is…?

• cognitive interpretation

• mostly learned

inattentional blindness

when something is in your field of vision, but you don’t see it

change blindness

you fail to notice the change that is happening in your field of vision

top-down processing

you see the whole and then examine the details

bottom-up processing

you examine the details to determine the whole

phi penomenon

when you see a series of images that give the illusion of movement

perceptual set

seeing something relative to it’s context

subjective contour

perceiving boarders as lines even though none are present

Gestalt

the whole is greater than some of it’s parts

closure

figure-ground

wants to see something in foreground and background

continunity

our brain wants to continue it

proximity

simplicity

we tend to see it in a more simple way

similarity

synesthesia

the senses are mixed up; out of alignment

ex: hearing different sounds makes you see different colors

monocular depth cue

being able to judge distance with only one eye

binocular depth cue

both eyes judge the distance

retinal disparity

difference that each retina sees

→ when it’s close, there’s a lot of retinal disparity

→ when it’s far, there’s not much of retinal disparity

→ the closer an object is to us, the greater the retinal disparity is that object

IT IS A BINOCULAR DEPTH CUE

mostly biological, partly learned

convergence

eyes move inward as object gets closer = signal is sent to brain

BINOCULAR DEPTH CUE

mostly biological, partly learned

accommodation

as an object draws closer, the shape of our eyeball (or lens) may actually change

MONOCULAR DEPTH CUE

mostly biological, partly learned

lens - projects light back into retina

pictorial depth cue

MONOCULAR DEPTH CUE

completely learned

• distal stimulus

• proximal stimulus

distal stimulus

the way something takes up space in the physical world

pictorial stimulus

the way something stimulates the retina (what your eye actually sees)

interposition

type of pictorial depth cue

an object getting in the way of another which in turn makes that object look closer than the other

relative size

same sized object = closer objects appear bigger

distal stimulus is same

proximal stimulus changes

texture gradient

clear detail when it’s closer

fuzzy detail when it’s far

motion parallax

distant objects = tend to move slower

closer objects = tend to move faster

aerial perspective

closer objects = towards ground and clear to see

distant objects = towards sky and hazy

linear perspective

closer to vanishing point = more distant

what do mixing red, green, and blue lights make?

white

what colors are part of the trichromatic theory of vision?

red, blue, and green

perceptual constancy

even though it might change the way it hits your eyes, the brain knows the object is still the same

→ color constancy

→ shape constancy

→ size constancy

subliminal messaging

a message will be embedded into another message that will affect someone in a way

it works but however the effect is very small, doesn’t change anyone’s behavior, and is temporary

FCC banned it'

paredidolia

to see order in randomness/disorder

back-masking

playing back a song or anything, thinking that there’s an embedded message in it

absolute threshold

also called fechnar’s law

when do we first start to notice things like smell, sound, etc?

at 50% threshold

Gustav Feshnar

just-noticeable difference (JND)

aka difference threshold

when you just notice the difference

weber’s law

• when the initial stimulus intensity is directly proportional to the JND size

ex: initial stimulus (3g) → JND (1g)

initial stimulus (30g) → JND (10g)

• when you add a bit to a bit, you can notice

• when you add a lot to a lot, you can notice

• Ernst Weber

sensory adaptation

• as the time time exposed to the stimulus increases, the stimulus intensity decreases

examples: blowing gum, walking into a flower shop, clothes touching your body, etc.

• when it comes to continuous stimulus, the intensity is not as much

wavelength has..

→ color (hue)

which color has the longest wavelength?

red

which color has the shortest wavelength?

violet

saturation (purity)

→ mixture of colors - ex: “yellowish red”

→ pure single color - ex: “red”

amplitude determines the..

brightness

what does a high amplitude mean?

it is bright

what does a low amplitude mean?

it is dim

cornea

protective layer outside of the eye

pupil

• how clear

→ when it’s bright, it gets smaller

→ when it’s dark, it gets larger

iris

• muscle that controls the size of the pupil

• colored ring around the eye

• responsible for dilating

ex: “principal iris is in charge of her pupils"

lens

projects light to back of eye

retina

if you’re colorblind, it is responsible for the distortion of colors you see

rods

• for movement

• black & white

• no light

cones

• colors

• fine detail

• in light

fovea

• loaded with cones

• whatever you’re looking at directly, the fovea is looking directly at that

foveal vision

center vision

optic disc

• where the blindspot is!!

• no photoreceptors here so it creates a natural blindspot for the eye

transduction

turning physical energy, like light, into brain signals

peripheral vision

outside of the center vision

the brain fills in the information for the blind spot & peripheral vision

what projects the image upside down?

the lens

what flips the image right side up?

the brain

what is the direction of the message/light?

rod/cone → bipolar cell → ganglion cell → towards optic disc

optic chiasm

the meeting point of the optic nerves before it makes its way to the thalamus

the more photoreceptors, bipolar, and ganglion cells you have the…

less detail you’re going to see

the less photoreceptors, bipolar, and ganglion cells you have the…

more detail you’re going to see

lateral inhibition

when one is being stimulated and the others are being hindered/stopped

what is another term for nearsightedness?

myopia

nearsightedness (mypoia)

• eye is FLATTER than normal

  moving closer to compensate → over-projected: far objects blurry

what is another term for farsightedness?

hyperopia

farsightedness (hyperopia)

• eyeball is TALLER than normal

  under-projected: close objects blurry → move away to compensate

elements of sound

→ frequency (pitch)

→ purity (timbre)

→ amplitude (volume)

pinna

captures sound

→ the outer ear that people can see

ear canal

sound goes through

ear drum (tympanic membrane)

end if the canal

ossicles (includes hammer, anvil, stirrup)

gets sound and violations

→ smallest bone

cochlea

where sound transduction occurs

auditory nerve

sound from the cochlea sent here then after sent to the brain

eustachian tube

below cochlea, it’s connected to the nose and throat

semicircular canals

filled with fluids, where out sense of balance is housed, the fluid shifts as we move

cochlea opened up..

once cochlea is hit by sound, it “waves”. the cilia (the tiny hairs) move within the basilar membrane

place theory

different areas of the cochlea, respond differently to different types of pitch (high, medium, low)

frequency theory

the pitch of the sound depends on the speed of the cilia

the higher the pitch, the faster it moves

the lower the pitch, the slower it moves

traveling wave theory (volley theory)

as a signal moves through, different hairs respond. And the brain puts there different stimulations together to create the sound.

auditory localization

localizing sound based on timing of the sound hitting the ears

ex: sound coming from left side, left ear catches it before the right ear catches it

gustation (taste)

• in order to be tastable, it has to water soluble!

  types of taste:

  → salty (can help us stay hydrated)

  → sweet (tells you there is calories/energy)

  → sour (tells us its gone bad)

  → bitter (tells us its poisonous)

  → umami - meat (tells you it’s protein)

spice is when our pain receptors kick in

olfaction (smell)

sense of smell does NOT go through thalamus, it goes directly to the brain straight ti olfactory bulb

has to be water soluble

NOT cross-lateralized, not catogorized, not gone trough thalamus,

smell is not as simple as other sense.

feature detectors

bottom-up processing requires

Hubel and Wiesel

tactile sense (touch)

• pressure

• pain

  • A fibers: fast pain

  • C fibers: slow pain

kinesthetic system (body position & movement)

receptors in our joints and muscles that enable us to know the position of our body.

vestibular system (balance)

helps with your sense of balance

→ cerebellum (in the brain)

→ semicircular canals (fluids in the ear)

gate control theory of pain

non-pain signals can help block out the actual pain signal

conduction hearing loss

→ refers to damages done to the ossicles

→ continuous damage causes damage

sensorineural hearing loss

→ degenerative, as you get older

→ in cochlea