chapter 8-motion perception Flashcards

1
Q

computation of visual motion

A

motion detector; change in position, two adjacent receptors registers change, a delay accounts for change in time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

motion is

A

change in position over time; activate receptive field at 2 different locations; 2 points in time in sequence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

detecting movement (diagram) is what kind of circuit

A

neural motion detecting circuit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

two input neurons with adjacent receptive fields feed into a

A

comparator neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

during stimulation with motion, the two inputs are stimulated at ___ times

A

different

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

for rightward motion, their responses arrive at the comparator ____

A

together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

evidence for motion detectors in ___ recordings

A

single cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

evidence for motion detectors because

A

many cells in cat and monkey visual cortex are direction selective, and respond very well to single direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

direction selectivity

A

responds well to 1 direction of motion much better than others, especially the opposite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

MT

A

higher level motion selective area; depth; signal motion at larger distances; broader range, larger receptive field

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

motion after effect

A

adapt to direction/pattern of motion, perceive opposite afterwards; illusion of motion of a stationary object that occurs after prolonged exposure to a moving object; motion opponent process; interocular transfer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what accounts for the motion after effect

A

classic opponent process; motion is seen in te direction of the team that wins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

with stationary pattern, is there motion seen

A

no, only moderate activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

with motion in one direction, what are the neurons doing

A

neurons are selective for that direction, winning but fatiguing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

after adaptation and in presence of stationary pattern, what happens

A

perceive motion in opposite direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

retinal image motion comes from what

A

movement of object in the world or movement from observers head/body/eyes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

moving car, stationary eye; leftward object motion results in right

A

displacement on the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

stationary car, moving eye; when you shift your gaze,

A

location of objects move on retina, but occulomotor muscles signal eye movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

observer motion

A

move eye/head/body and retinal image changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

optic flow

A

changing angular positions of points in a perspective image that we experience as we move through the world; local velocities on the retina inform about motion; motion in depth, low velocities in the center, high velocities in the periphery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

eye movement commants

A

motor system tells eyes to change position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

saccadic suppression

A

the reduction of visual sensitivity that occurs when we make saccadic eye movements; eliminates the smear from retinal image motion during an eye movement

23
Q

smooth pursuit

A

eye smoothly follow a moving target

24
Q

saccade

A

rapid movement of the eyes that changes fixation from one object or location to another; jumps; 7-9 letters, 15 to the right and 3-4 to the left

25
vergence
two eyes move in opposite directions, as when both eyes turn toward the nose
26
reflexive
automatic and involuntary eye movements; eyes move to compensate for turning head/body so that eyes will stay focused on point
27
mystagmus
eye jitters
28
optokinetic nystagmus
jerk in the direction of motion when trying to fixate
29
real movement
continuous change in position in a natural image
30
apparent movement
discontinuous change in positions (series of locations); rapid alteration of objects
31
distance time trade off
when objects are close together, can be fast flicker and see motion, as distance increase time delay must increase also
32
receptive field size grows as you get __ in visual system
higher up
33
good apparent movement is
indistinguishable from real movement
34
cortical direction selective cells respond to
apparent movement
35
apparent movement ___ neural detectors in the ___ way as real movement
excites, same
36
the aperture problem
the fact that when a moving object is viewed through an aperture, the direction of motion of a local feature or part of the object may be ambiguous
37
aperture
opening that allows partial view of an object
38
what cells have the aperture problem
V1
39
with aperture, ___ is ambiguous
local motion
40
if motion within aperture is ambiguous, how does visual system correctly perceive overall motion
motion info from several local apertures (RFs) combines to determine the global motion; whichever possible motion is the same for all apertures
41
combining info from different apertures happens where
MT
42
biological motion
pattern of movement of living things
43
tau
info in the optic flow that could signal time to collision without the necessity of estimating absolute distances or rates
44
distinctions between processes
short range vs long range first vs second order feature tracking
45
first order
change in position of luminance defined objects
46
second order
object defined by changed in contrast or texture; focus of expansion
47
feature tracking
motion perception for any stimulus where a change in position occurs, happens slowly
48
some neurons are ___ selective motion detectors
directionally
49
brain uses several strategies to distinguish between __ and __ motion
object and observer
50
___ motion can be explained by responses in neural motion detectors
apparent
51
issues about ambiguous local motions are solved with ____
global motion detectors
52
evidence indicates that 2 or more subsystems mediate motion perception
2
53
correspondence problem
in binocular vision the problem of figuring out which bit of the image in the left eye should be matched with which bit in the right eye; in motion detection, the problem faced by the motion detection system of knowing which feature in frame 2 corresponds to a feature in frame 1