Motion

Question 1

motion

Answer 1

change in position/location over time

Question 2

motion aftereffect (MAE)

Answer 2

the illusion of motion in a stationary object after prolonged exposure (adaption) to movement

evidence of interocular transfer - can adapt one eye and still get after image in other

opponent process system

Question 3

apparent motion

Answer 3

brain assuming same object is showing up in a different place after it disappeared from another place

Question 4

2 ways we perceive motion from what we already know

Answer 4

motion detection cells
- particular cells taking info from eye, V1, etc. to digest motion

where pathway

Question 5

periphery is quite good at _______ ______, meaning this part of the LGN is also good at this

Answer 5

detecting motion; Magnocellular layer

Question 6

where the where path ends

Answer 6

parietal cortex

Question 7

___ cells can code for motion

Answer 7

V1

Question 8

issue with having only V1 cells to detect motion and the solution

Answer 8

response would be similar for actual motion vs. two separate images in those receptive fields

solution: add additional system to calculate timing

Question 9

delay cells

Answer 9

as they sound, serve to process a delay from cell 1

Question 10

multiplication cells

Answer 10

only fire when D1 (delay cell of cell 1) and cell 2 simultaneously fire

Question 11

aperture problem

Answer 11

when you (or cells) can only see small window (aperture) of the world, it can become hard to know how objects are moving

through window we see one motion while the whole picture shows us a different motion, true with gratings as well

shows us that we can’t rely on a couple of V1 cells to understand motion alone

Question 12

what part of the brain has an impact on ability to detect global motion when damaged?

Answer 12

hMT (human middle temporal cortex)

Question 13

another term for hMT (bonus points if you know what cortex this can be categorized as)

Answer 13

V5; extrastriate cortex (V+#)

Question 14

akinetopsia

Answer 14

motion blindness
- vision is like a set of still images; for some, kind of like strobe lights or more severe. leaves after images!

caused by damage to hMT

Question 15

some drugs result in ___ __________ (type of motion blindness)

Answer 15

acute akinetopsia

Question 16

first-order motion

Answer 16

changes in luminance over space/time

Question 17

second-order motion

Answer 17

changes in contrast or texture where overall luminance stays the same

Question 18

________ motion seems to be particularly priviledged, why?

Answer 18

biological; this is because the motor regions of the brain that is activated when recognizing are the same regions that are involved in the action itself

Question 19

optic flow

Answer 19

the changing angular position of points as we move through space

Question 20

focus of expansion (FOE)

Answer 20

center point from which motion seems to expand outward from

though to be how pilots start the process of landing a plane by focusing on whether the runway is expanding symmetrically

Question 21

time-to-collision (TTC)

Answer 21

helps you decide whether something is coming at you/if you need to move out of the way

optic flow gives much of this information

Question 22

tau

Answer 22

size of retinal image relative to expansion rate

basically a heuristic estimate of whether an object is rapidly expanding and taking up a lot of retinal image

Question 23

motion induced blindness

Answer 23

not full blindness, but motion can cause static parts of an image to seemingly vanish

static dots will wink out

tied to global position

Question 24

motions of our eyes

Answer 24

fixations
- when our eyes are focused on one area

saccades
- when our eyes move sharply between points

micro-saccades
- even when we are fixated, our eyes are making small movement adjustments (preventing fading/adaption)

smooth pursuit
- when our eyes steadily follow motion

reflexive eye movements
- automatic eye movements, e.g. when you move your head without changing fixation

vergence
- rotating eyes inward (converge) or outward (diverge)

Question 25

superior/inferior oblique eye muscles

Answer 25

control left to right/rotations

Question 26

superior/inferior rectus eye muscles

Answer 26

control up and down

Question 27

lateral/medial rectus

Answer 27

control back and forth

Question 28

our eye muscles allow for movement but also …

Answer 28

communicate that movement to the brain

Question 29

superior colliculus

Answer 29

mid-brain structure critical for controlling eye movements

evidence this brain region gets direct input from retinal ganglion cells, skipping the LGN –> V1 pathway

Question 30

eye movements in the brain get information from the ____ pathway and coordinates with _____ _______ _____ (FEF) to guide eye movements

Answer 30

where; frontal eye fields

Question 31

is voluntarily moving your eye vs. jiggling it with your finger the same?

Answer 31

no

Question 32

saccadic suppression

Answer 32

while you make a saccade, your brain stops taking in new information until fixation, particularly through the magnocellular pathway

which means you can miss small amounts of motion that occur while you move your eyes

doesn’t happen when you jiggle your eye

Question 33

benefit of saccadic suppression

Answer 33

world doesn’t “smear” as you move your eyes

Question 34

efference copy

Answer 34

when an eye movement is executed, signal is sent to not only the eye, but sensory cortices

Question 35

camparator in the visual system

Answer 35

taking change in stimuli and change in efference copy to see what is true stimuli/what happened

Question 36

cells in regions like the parietal cortex and frontal eye fields actually remap their …

Answer 36

receptive fields in anticipation of an eye movement

Question 37

receptive field remapping allows us to …

Answer 37

do motion perception so quickly, can happen in anticipatory fashion

Question 38

2 places motion happens

Answer 38

from the world and from our eyes

Question 39

what 2 parts of our brain allow us to efficently track where and how something is moving in our world

Answer 39

mid-brain structures (motor and sensory cortex)
where pathway

Question 40

When a pair of lights flicker on and off in opposite
patterns from each other, this can create _______.

a. Saccadic Suppression
b. Apparent Motion
c. An Efference Copy
d. Second Order Motion

Answer 40

b

Question 41

What is the earliest part of the brain that, when
damaged, causes deficits in motion detection?

a. LGN
b. V1
c. hMT/V5
d. Parietal Cortex

Answer 41

a