ap psych mod 1.6

sensation

process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment

sensory receptors

sensory nerve endings that respond to stimuli

perception

how our brain organizes and interprets sensory info, enabling us to draw meaningful conclusions

bottom-up processing

begins w/ sensory receptors and works up to the brain’s integration of sensory info; often used for new situations

top-down processing

guided by our higher-level mental processes, we process details based on our experience and expectations

can be biased/overestimated

what’s the problem w/ top-down processing?

transduction

conversion from 1 form of energy into another

receive, transform, deliver

steps of transduction

receive

physical input of some kind reaches our sensory cells

transform

physical signal must convert to a nerve impulse (this is transduction)

deliver

signal travels to correct brain location

psychophysics

study of relationships btwn physical characteristics of stimuli, such as their intensity and our psychological experiences of them

absolute threshold

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

a beep in a quiet room from a certain distance

threshold for hearing?

smallest light you could see in a dark room from a certain distance

threshold for seeing?

a single spritz of a scent in a certain space

threshold for smelling?

theory that argues that absolute thresholds don’t exist, and they depend on a person’s experience, expectations, motivation, and alertness

what is the signal detection theory?

Gustav Fechner

who made the signal detection theory?

predicts how and when we detect the presence of a faint stimulus (signal) amid the background stimulation (noise)

what does the signal detection theory predict?

subliminal

stimulus below one’s absolute threshold for conscious awareness

difference threshold

minimum difference btwn 2 stimuli required for detection 50% of the time; a “just noticeable” difference

weber’s law

2 stimuli must differ by a constant minimum percentage (rather than a constant amount) to be perceived as different

higher up you go in weight, it’s harder to guess what’s heavier (2lb vs 3lb → 20lb vs 21lb)

example/application of weber’s law?

sensory adaptation

diminished sensitivity due to constant stimulation; does not mean getting used to something

occurs because nerve cells fire less frequently; we tend to focus on new or changing stimuli over constant ones

why does sensory adaption occur?

getting used to a sound and tuning it out/not paying attention to it anymore

example of sensory adaptation?

sights we see would vanish because of adaptation, except our eyes are constantly moving, thus changing the stimulus

why does sensory adaption not apply to vision (so why don’t we stop seeing things after a while)?

wavelength

distance from peak of 1 light/sound wave to peak of the next

hue

determined by wavelength of light, basically the ‘color’ that we interpret

intensity

determined by wave amplitude (height)

affects energy carried by a wave which in turn affects brightness/loudness of colors

what does amplitude affect?

cornea

clear, protective outer layer, in front of pupil and iris

pupil

“black” center of eye, opening through iris that allows light to enter

iris

colored muscle circling the iris that opens and closes the pupil

iris

what is the only colored muscle in the body?

lens

clear, hard bi-concave disc that focuses light on retina

accomodation

process of lens changing shape to focus near vs far objects

ciliary muscles

surround lens and changes its shape

retina

thin layer covering back of eye

rods, cones, and neurons

what does the retina contain?

receives an inverted image from lens

what does the retina receive?

fovea centralis

central focal point on retina

fovea centralis

where do cones cluster

rods

receptors that detect black, white, and gray, and are sensitive to movement

helps w/ peripheral and twilight vision

what do rods help w/ ?

cones

detect fine detail and color vision

cluster around the fovea and require higher light levels

cones location?

bipolar cells

receive input from rods and cones and start nerve impulse

ganglion cells

activated by bipolar cell; axons of may of these cells align to form optic nerve

blind spot

where optic nerve leaves eye; no receptors here

cornea → pupil → lens → retina → rods and cones

order in which light travels

bipolar cells → ganglion cells → optic nerve → optic chiasm → thalamus → visual cortex of occipital lobe

order in which nerve impulse travels

retina contains 3 different types of color receptors (cones) sensitive to red, green, and blue light

what is the young-helmboltz trichromatic (3-color) theory?

combo and proportions of cones stimulated

what allows for perception of any color?

~1-2 in males and ~1-200 in females

color blindness rarity in males vs females

they’re lacking some or all the red or green sensitive cones, or both

why do people have color blindness?

red-green is most common dichromatic form w/ sex-linked inheritance

most common form of color blindness

monochromy

no color vision

theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision

what is the opponent-process theory

some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green

example of opponent-process theory

feature detectors

nerve cells in brain’s visual cortex that respond to specific features of 1 stimulus like shape, angle, and movement

uses parallel processing to analyze multiple aspects simultaneously

feature detectors use what to do what?

fusiform face area helps us to recognize faces from various viewpoints after rearranging angles, colors, size, and shape

what does fusiform face area help us do?

audition

sense/act of hearing

allows for communication, provides info, and helps us to survive and adapt

audition allows for what?

widr range with humans being the best heard

what is the range for normal hearing among humans?

sounds

neural responses to what are transmitted much faster - sounds or visions?

frequency

number of complete wavelengths that pass a point in a given time

hertz (Hz)

measurement of frequency

pitch

tone’s experienced highness or lowness

frequency

pitch depends on what?

true

t/f : low pitch = low frequency

determined by amplitude of sound waves

what is loudness determined by?

decibels (dB)

measurement of loudness

60 dB

loudness of normal conversations

over 85 dB

when can hearing loss occur?

auditory canal → eardrum → malleus → incus → stapes → oval window → cochlea

path of a sound wave

middle ear

chamber btwn eatdrum and cochlea containing 3 tiny bones which concentrate the vibrations of the eardrum on the cochlea's oval window

malleus, incus, stapes

3 bones in the middle ear

the ear - malleus, incus, stapes

where are the smallest and most delicate bones in the body?

inner ear

innermost part of ear, containing cochlea, semicircular canals, and vestibular sacs

cochlea

coiled, bony, fluid-filled tube in inner ear

oval window

where stapes transmit vibrations to

cause cochlear fluid to move (bends tiny hair cells lining the cochlea)

what do vibrations cause?

nerve impulses

what do hair cells trigger?

auditory nerve

where nerve impulses are transmitted down

sensorineural hearing loss

most common form of hearing loss

caused by damage to cochlea’s receptor cells or to the auditory nerve; aka nerve deafness

cause of sensorineural hearing loss

conduction hearing loss

less common form of hearing loss

damage to the mechanical system that conducts sound waves to cochlea

cause of conduction hearing loss

cochlear implant

device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea

determined by how many hairs were triggered

what is loudness determined by?

theory that links pitch we hear w/ place where the cochlea’s membrane is stimulated

what is the place theory?

theory that rate of nerve impulses traveling up the auditory nerve matches frequency of a tone, thus enabling us to sense pitch

what is the frequency matching theory?

place coding

what is place theory also known as?

temporal coding

what is frequency matching theory also known as?

largest organ and largest sense receptor

skin is our largest what?

pressure, warmth, cold, pain

4 basic touch sensations

human touch - it’s a tactile sensation that we need from the beginning of life, and even adults still benefit from the touch of a loved one

what promotes our well-being?

different combos of the 4 sensations, as well as intensities

what creates a myriad of perceptions?