quiz 3 review neuro

convergence

eyes turn inward; something is close

ball comes close to face

ciliary muscles contract, zonule fibers relax, lens rounds/thickens

occlusion

monocular cue; something is in front of another

familiar size

monocular cue; logic to understand close/far based on how big something should be

relative size

monocular cue; smaller=farther if they are the same object

perspective convergence/linear perspective

monocular cue; in 3D, everything converges to vanishing point

ponzo illusion

far away line takes up the same amount of space but seems father, therefore looking bigger

horizon line

monocular cue; closer to line=farther, higher up= closer

atmospheric effects

monocular cue; scattered blue light gives farther things a blue tint

chromostereopsis

red has a longer wavelength than blue so lens must accomodate to make them hit retina at the same place

texture and shadow

monocular cue; farther=less texture, more shadow = depth

motion parallax

monocular cue; closer=faster, father = slower

deletion/accretion

monocular cue; occlusion with motion shows which are closer/farther

binocular disparity

difference between left and right eye

strabismus

lazy eye; overlap between eyes creates headaches, slowly uses one eyes vision over time

corresponding points

light hitting same point on left and right retina; when you are foveating on something

horopter

anything along corresponding points will hit horopter, meaning they are on the same depth

binocular disparity

measure of disparity between what would be corresponding point and the actual point

crossed disparity

in front of horopter; close to you

uncrossed disparity

behind horopter; farther from you

stereopsis

perception of depth

stereoscope

two separate images directed at each eye, creates depth; closer= more shifted

disparity selective neurons

allow us to see fine depth differences

illusory motion

flashing lights consecutively seems like motion

induced motion

staring at something for a long time causes motion when image disappears; because downwards neurons get tired but upwards still fire at baseline

perceived motion

need activity in MT

local disturbance

person moves across vision but something is stationary in background; seems like both are moving because of eye movement

global optic flow

everything in a scene is moving means that we are moving/our eyes are moving

efference copy

copy of the signal sent from superior colliculus to motor neurons; sent instead to cortex

understanding motion in brain

CDS creates efference copy and sends to cortex, image displacement signal is sent from retina to cortex, both signals are compared, MST compares them

IDS and efference copy are the same

no motion; eyes moved and things changed or eyes didn’t move and nothing changed

IDS and efference copy different

motion; eyes moved and things didn’t change or eyes didn’t move and things changed

direction selectivity

in layer 4B of V1; there is a delay unit meaning signal needs to hit at the same time which will cause there to be enough depolarization when it hits the next neuron due to delay unit

moving dot displays

MT activated in a certain direction and light moving in a certain direction causes perception in middle of those two

limited resouce hypothesis

brain would have to process 2 MB/data per second so we have to train our attention

dorsal attention network

voluntary; IPS and SPC create a map of the world

ventral attention network

involuntary; VFC and temporal parietal junction

covert attention

pay attention to thing in periphery

overt attention

pay attention to something you’re directly looking at

saccade

fast ballistic eye movement to foveate on a object; blind to stop motion sickness; prevents fatigue

efficiency search slope

x-axis: time, y-axis: set size

salience

pop-out effect; flat efficiency search slope

parallel/stimulus driven search

see everything in parallel, can look at whole picture; high salience

conjunction/goal driven search

combine info; have to look at image in parts; steeper slope

scene-based guidance

schema to understand where something should be in a picture, lower slope than conjunction

change blindness

can’t recognize change that we’re not paying attention to

posner’s theory on attention

1. alerting: something happens

2. orienting: where to look

3. actually attending

pre-cuing

being told where to pay attention; will do it even if you know it’s wrong

preattentive

features of object are separated, percieving but not attending

stages of attention

preattentive, focused attention, binding

focused attention

features bound into coherent perception

binding

features combined to create coherent objects

reflectance curve

how much of each wavelength is reflected

higher total reflectance curve

lighter color

lower total reflectance curve

darker color

subtractive color mixing

what is absorbed stays absorbed; primary are cyan, magenta, and yellow

additive color mixing

what is reflected stays reflected; primary are red, green, blue

metamers

can’t tell the difference between certain colors because cones are acting in the same ways

L cones

long wavelength

M cones

medium wavelength

s cones

short wavelength