Premed95 P/S

what cues are taken into account when "perceptually organizing"?

depth, form, motion, constancy

what do binocular cues provide?

depth perception(due to retinal disparity)

what is convergence?

gives depth perception based on how much eyes are turned inward

what do monocular cues provide?

relative size, interpositon, relative height, shading/countour, motion (through motion parallax), constancy

how does your inner ear adapt to loud noises?

muscle contracts TM to prevent damage

what is proprioception?

sense of "self in space"

what is just noticeable difference?

threshold at which you can notice a change in sensation

weber's law?

the ratio of background intensity to incremental intensity is constant

what is absolute threshold of sensation?

minimum intensity of stimulus needed to correctly detect it 50% of the time

what is a subliminal stimulus?

stimulus that is just below our absolute threshold of sensation

thermoception

temperature

mechanoception

pressure

nociception

pain

proprioception

position

non adapting neuron

neuron fires at constant rate

slow adapting neuron

neuron fires rapidly at first then tapers off

fast adapting neuron

fires as soon as stimulus starts, stops, then starts up again once stimulus stops

what portion of the inner ear helps determine strength of rotation/movement of head?

endolymph inside semicircular canals

otolithic organs?

utricle and saccule--calcium carbonate crystals that drag hair cells with the help of gravity to determine position

what is signal detection theory?

discerning between important and unimportant stimuli. Can have hit, miss, false alarm, or correct rejection

what is d' (d prime, signal detection theory)?

strength of a signal

what is c (signal detection theory?)

strategy used

what is the liberal strategy (signal detection theory?)

always saying yes, youll get all the hits but might get false alarms

what is the conservative strategy? (signal detection theory)

always say no unless 100% sure, will correctly get all false rejections but might get some misses

what is bottom-up processing?

stimulus affects our perception, data driven

what is top-down processing?

uses background knowledge to influence perceptions (cube illusion). theory driven 

what is gestalt's law of similarity?

items similar to one another grouped together

what is gestalt's law of pragnanz

reality reduced to simplest form possible (think, olympic rings). instead of seeing 5 rings you see olympic logo

what is gestalt's law of proximity?

items that are close together are grouped together

what is gestalt's law of continuity?

lines are seen as following smoothest possible path

what is gestalt's law of closure?

objects grouped together are seen as whole (filling in a triangle where there is none, pacman shit)

what is gestalt's law of symmetry?

you perceive symmetry in objects and forming around a central point

what is the conjunctiva?

thin layer of cells covering cornea

what is the cornea and its fxn?

covers over pupil, serves to bend light slightly. Composed of thick connective tissue

where is the anterior chamber of the eye?

in front of the pupil.

what is the aqeous humor?

composes the anterior chamber, provides support, in front of pupil

what is the pupil?

opening in middle of iris. opens and closes due to iris contraction.

what is the iris?

the muscle that contracts to change the shape of the eye. is colored

what is the lens of the eye?

located behind pupil, bends light towards fovea. changes shape based on suspensory ligaments

what is the ciliary body?

suspensory ligaments+ciliary muscle

what is the posterior chamber?

area between iris and lens, filled with aqueous humor

what is the vitreous chamber?

filled with vitreous humor, jelly like substance, gives pressure to eye

what is the retina?

covers back of eye, contains many of the necessary photoreceptors

what is the macula?

area of retina with high cone density

what is the fovea?

special part of macula that has ONLY cones

what do cones do?

detect color, high detailed shit

what do rods do

detect light, not as fine detail

what is the choroid?

black pigmented network of blood vessels used to nourish the eye

what is the sclera?

thick fibrous tissue covering posterior 5/6 of eye. (1/6 covered by cornea)

what happens when light hits a rod?

rod turned OFF-->bipolar cell turned ON-->retinal ganglion cell turned ON-->goes to brain

what happens to retinal when struck by light?

converts from cis-retinal to all trans retinal

what are the basic steps of the phototransduction cascade?

light hits retinal-->retinal changes conformation to trans-->rhodopsin protein changes conformation-->transducin released-->transducin binds and inactivates phosphodiesterase-->lower levels of cGMP-->Na+ channels close-->rod turns OFF

what are optic discs?

located inside rods/cones. contain proteins that fire APs to brain

are there more rods or more cones?

more rods

rods are specialized for perceiving?

light vs dark, black vs white, very sensitive to light vision

rods have a very \___ recovery time compared to cones,

slow. which is why takes time to adjust to a dark room

cones are found primarily in the 

fovea

there is a blind spot in the eye where

the optic nerve connects

why is there higher resolution at the fovea?

no axons in the way of light entering

the right visual field goes to the \__ side of the brain

left

light from the left visual field will strike..

the right temporal and left nasal retinas

light from the right visual field will strike the

left temporal and right nasal retina

nerves from the nasal retinas cross over at the

optic chiasm

what are the 3 elements of feature detection?

color, form, motion

what is the parvo(cellular) pathway?

good at detecting spatial region (boundaries,shapes, etc)

what is the magno(cellular) pathway?

good at detecting motion

what is audition?

our sense of sound

what are the 2 things needed to perceive sound?

pressurized sound wave and hair cells in ear

higher or lower wavelength penetrated deeper into cochlea?

higher wavelength, smaller frequency, travels further

what is the outer(visible) part of the ear known as?

pinna

what are the 3 bones in the inner ear?

malleus, incus, stapes(hammer, anvil, stirrup). AKA ossicles

the stapes is attached to the \____

oval window, pushes in when vibrating

what is the function of the round window?

bulges out when fluid pushes against it

what is the organ of corti?

basilar membrane/tectonic membrane. 

what portions of the ear are the outer ear?

from pinna --> TM

what portions of the ear are the middle ear?

where the ossicles are

what portions of the ear are the inner ear?

the cochlea/semicircular canals

the fluid pushes on what part of the hair cell?

the hair bundle, composed of kinocilia

what causes the action potiential to be sent down the auditory nerve?

kinocilia move, connected to tip link, tip link movement allows K+ flow, leading to AP sent to spiral ganglion cell

what frequencies can humans hear?

20Hz to 20kH

what is basilar tuning?

how brain differentiates between different frequencies. hair cells at base of cochlea activated by high freq and apex of chochlea are activated by low freq (think, low freq means high wavelength so it travels faster)

what is sensory adaptation?

receptor changing over time due to stimulus. can downregulate or upregulate (think hand on table, no change in pressure so receptor will stop firing until it changes again)

what is the somatosensory homunculus?

map of body in brain, specific region of body has specific region in cortex

what is found in muscles that give us information about how they are stretched?

spindle fibers

what is kinaesthesia and how is it different from proprioception?

kinaesthesia is more behavioral while proprioception is more subconcious. more related to movement than sense of position in space

what is the the TrpV1 receptor?

receptor that causes signaling for both heat and pain. 

what are alpha-beta fibers

thick, lots of myelin. supah fast nerve conduction

what are alpha-delta fibers

smaller than alpha-beta, less myelin

what are c fibers

small, unmyelinated

what is the collection of nerves, sitting above the cribiform plate, that allows olfaction?

olfactury bulb, projected down into olfactory epilthelium with receptors

what are the 5 main tastes?

sweet, sour, bitter, salty, umami(glutamate)

what is the labelled line model of gustatation?

each taste bud has 5 different axons that syanpse at 5 different cortical locations

sour and salty molecules rely on \__ channels

ion

bitter, sweet, and umami rely on \___ receptors

GPCR

what is conciousness?

awareness of self and environment

what waves are alertness associated with?

beta waves

"what waves are ""daydreaming""/relaxed state associated with?"

alpha waves

what waves are drowsiness associated with?

theta waves

N1 stage of sleep is dominated by

theta waves, hallucinations, hypnic jerks

N2 stage of sleep

deeper than N1, precedes N3, see lots of theta waves, sleep spindles, and K complexes