Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Survey of the Senses > Midterm 3 - Topic 10 > Flashcards

Midterm 3 - Topic 10 Flashcards

1
Q

Motion definition

A

Change of location over time

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

Motion and the retina definition

A

Change of location over time but on the retina

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

Motion after effect (MAE)

A

View an object moving in one direction
We perceive a stationary object as having a contrary direction of motion after adaptation

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

Explain the motion after effect

A

Fatigue of motion detectors for one direction of movement somewhere in the brain

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

Motion integration
Why does this make sense?

A

Motion perception requires integration of the input from many neurons in the association cortex, most likely in the medial temporal (MT) area
We need more than two receptors to perceive motion
Each receptor has a limited receptive field

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

Pathway for motion perception

A

From magnocellular neurons in the retina and LGN, to V1 in the cortex, to area MT (among others)

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

First order motion

A

Motion that involves objects defined by differences in luminance (including colour differences)

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

Second order motion

A

Motion that involves objects defined by differences in texture or contrast

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

Best example of second order motion

A

Camouflage

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

Coping with eye movements

A

Term retinal flow is much better than retinal image
Retinal image is also affected by voluntary eye movements

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

For this condition, give the retinal condition and the association perception: Sweeping eye movements

A

Constant change in pattern of retinal receptors stimulated
No motion

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

For this condition, give the retinal condition and the association perception: Stationary eye, single object in motion

A

Successive retinal receptors stimulated by object
Object motion

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

For this condition, give the retinal condition and the association perception: Stationary eye, entire field in motion

A

Constant change in pattern of retinal receptors stimulated
Observer motion

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

For this condition, give the retinal condition and the association perception: Observer fixates moving object

A

Constant change in pattern of retinal receptors stimulated except for fixated object
Object motion

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

For this condition, give the retinal condition and the association perception: Observer fixates object and turns head

A

Constant change in pattern of retinal receptors stimulated except for fixated object
Head movement

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

For this condition, give the retinal condition and the association perception: Observer in motion with fixation point maintained on single object

A

Constant change in pattern of retinal receptors stimulated except for fixated object
Observer motion

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

For this condition, give the retinal condition and the association perception: Observer in motion without fixation point

A

Constant change in pattern of retinal receptors stimulated
Observer motion

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

Why don’t we see the world as constantly shifting?

A

In part because of saccadic suppression
Additional mechanism is provided by the eye-head system

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

Eye-head system

A

Takes into account eye movements and changes in the retinal image to determine whether motion is present in the visual field

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

What must be taken into account to perceive motion?

A

Interaction of the info provided by retinal image change and voluntary eye movements

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

Corollary Discharge Theory

A

Comparison structure compares a corollary discharge sent by the brain with a signal about sensory info (movement) on the retina
The corollary discharge is a copy of the command sent to the muscles

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

Using Corollary Discharge Theory, how does the visual system determine whether movement has occurred in the environment?

A

By comparing the info from muscular and visual sources

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What brain structure is likely the comparator in the Corollary Discharge Theory?

A

Superior colliculus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does the comparison structure do in the Corollary Discharge Theory?

A

Where the visual system determines whether movement has occurred in the environment by comparing the sensory and muscular info

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What do the corollary discharges produce?
Expectations about the sensory info When the sensory signal is consistent with the expectations, no movement is perceived If sensory signal and expectations are inconsistent, motion is perceived
26
Velocity detection threshold
Minimum velocity that can be detected
27
How is velocity detection threshold usually expressed?
In minutes of visual angle per second
28
What is the velocity detection threshold for humans?
Varies between 10 to 20 min/secs
29
Factors affecting the velocity detection threshold
Uncertainty Background Area of the retina stimulated
30
Uncertainty as a factor affecting the velocity detection threshold
The VDT increases when the observer is uncertain about which way the target will move
31
Background as a factor affecting the velocity detection threshold
With a textured background, the VDT decreases to about 1 to 2 min/sec
32
Area of the retina stimulated as a factor affecting the velocity detection threshold
More sensitive to motion in the fovea than in the periphery Periphery still important but has a higher threshold
33
Who developed the event perception approach?
J.J. Gibson and Gunnar Johansson
34
Hallmark of the event perception approach
Object motion is considered an event
35
What do researchers who use the event perception approach emphasize?
The meaning of motion rather than the perception of motion itself Focus on natural situations
36
What is one of the main interests of the event perception approach?
Biological motion Pattern of movements found in living things
37
How did Johansson conduct the first study on biological motion in 1973?
He attached small lights to the main joints of a male subject (elbows, wrists, hips, head, knees, ankles) He then made a movie of this man as he moved around in a dark room
38
Results of Johansson's pioneer study
Observers could easily interpret movement in isolated dots moving in pattern No extra cues such as the contours of body parts are needed to recognize complex movements Only 12 tiny lights!
39
What did Johansson conclude from this pioneer study?
The visual system must have fixed pathways from the retina to the cortex to allow us to identify movement quickly
40
Stroboscopic movement
This type of movement is produced by a rapid pattern of stimulation on different parts of the retina Fits perfectly with how we defined motion earlier
41
Autokinesis AKA
Self-induced movement
42
Autokinesis
Observed whenever a stationary object with no clear background appears to move Presumably caused by the involuntary eye movements
43
Induced movement
Occurs when a visual frame of reference moves in one direction and produces the illusion that a stationary target is moving in the opposite direction
44
What is the most common explanation for induced movement?
Frame of reference theory
45
Frame of reference theory
Our visual system is predisposed to perceive small and centrally located areas as moving
46
What is the frame of reference theory supported by?
The finding that autokinesis is reduced when a stable frame of reference is provided The moving room experiment
47
What does the moving room by Lee (1974) show?
Visual info is much more important than mechanical information in infants Less so in adults, but in unfamiliar balancing tasks, they tend to fall just like infants do
48
3 classes of theories of motion perception
Physiological Direct perception Computational
49
Physiological theory of motion perception
Magnocellular system and area MT Superior colliculus as possible comparator in the corollary discharge theory
50
Direct perception theory of motion perception
Reliance on various cues to perceive motion: Relative movement Occlusion and disocclusion Image size Motion parallax Motion perspective Binocular cues
51
Explain relative movement as a cue to perceive motion
If an object is moving relative to you and you're not moving, you know it must be moving
52
Explain image size as a cue to perceive motion
If an object is getting bigger, you know it must be moving towards you
53
Explain motion parallax as a cue to perceive motion
Changes in the rate of motion parallax when objects are moving with us
54
Explain motion perspective as a cue to perceive motion
Image of objects flow across your retina at a different rate
55
Explain binocular cues as a cue to perceive motion
Relative speed of movement for each eye Produce more disparity in one eye than other
56
What does the direct perception approach claim?
That we use all the above sources to perceive motion We do not need internal mechanisms to perceive movement This theory ignores physiological evidence
57
What does the computational approach of motion perception combine?
The richness of info in the visual world Knowledge acquired from experience Movement processing modules
58
Why should we care about motion perception?
Understanding motion perception helps us understand why some people get motion sickness Motion perception also explains how movies are made!
59
What are the semi-circular canals part of?
The vestibular sense
60
What does the vestibular sense provide?
Info about our orientation, movement, and acceleration
61
Where are the receptors for the vestibular sense located?
Semicircular canals Utricle Saccule
62
What are the three structures that have receptors for the vestibular sense part of?
The labyrinth
63
What is the receptor found in the semicircular canals called?
Crista
64
Where specifically is the crista located?
In the ampulla of the semicircular canals
65
What is the crista made of?
A gelatinous substance (cupula) with hair cells embedded in it
66
What are the semi-circular canals filled with?
Fluid (endolymph)
67
What happens when there is a linear acceleration in the semicircular canals? What does this cause?
When the head moves the liquid is displaced Causes movement of the cupula, bending the hairs and activating an action potential signalling head movement
68
Explain how the semicircular canals encode three spatial dimensions
They are approximately orthogonal to each other The canals are arranged in such a way that each canal on the left side has a parallel counterpart on the right side Each of these three pairs works in a push-pull fashion: when one canal is stimulated, its corresponding partner on the other side is inhibited, and vice versa
69
What does the push-pull system in the semicircular canal allow us?
To sense all directions of rotation Thus, the give us a sense of our head's orientation
70
What are the utricle and saccule?
Small sacs filled with fluid
71
What is the receptor organ found in the utricle and saccule called?
The macula
72
What is the macula composed of?
Hair cells embedded in the inner surface of the main structure
73
What are the otoliths?
Calcium crystals lying on top of the gelatinous substance forming the macula The hair cells are bent by the otoliths depending on the direction of displacement or the body's position with respect to gravity With linear acceleration, slowing down or head tilt, the inertia of the otolith particles changes the shape of the gelatinous substance and produces a bending of the hair cells
74
What does the otolith movement produce?
A firing of the nerve fibres, sending info about the acceleration or head tilt to the brain
75
Where is info from the crista and the macula sent to?
The vestibular nuclei in the brainstem
76
Give a summary of self motion perception
The role of the utricle and saccule is the perception of linear acceleration of the head The role of the crista involves perception of rotary acceleration along any head axis
77
Why should we care about self-motion perception?
Dizziness is caused mostly by the crista Motion sickness is caused mostly by the macula

Survey of the Senses (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions