Sensory Components Of Motor Control Part 2

Question 1

Vestibular system

Answer 1

Sensory system responsible for providing brain with info about motion, head position and spatial orientation involved with motor functions

Question 2

What does the vestibular allow us to do

Answer 2

Keep balance
Stabilize head and body during movement
Maintain posture

Question 3

3 parts of vestibular structure

Answer 3

Otoliths (utriculus and sacculus)
3 semi-circular canals

Question 4

Otoliths

Answer 4

Stones or crystals that detect linear acceleration, head tilt and gravity

Question 5

2 type of otoliths

Answer 5

1. Utriculus (anterior-posterior motion)
   - speed up slow down in car
2. Sacculus (vertical movement)
   - elevator

Question 6

3 semicircular canals

Answer 6

Detect angular (rotational) acceleration
- anterior, posterior, horizontal/lateral

Question 7

What do otoliths sit on

Answer 7

Hair bundles

Question 8

Neural connections of vestibular system

Answer 8

Afferent via 8th cranial nerve to vestibular nuclei in medulla
Efferent sets gain of vestibular system

Question 9

Gain

Answer 9

Change in the eye angle divided by the change in head angle during the head turn

Question 10

What does gain modulation allow

Answer 10

CNS to pay more or less attention to vestibular system
- depends on task

Question 11

The vestibular neural connections are what compared to visual ones

Answer 11

Faster

Question 12

4 functions of vestibular system

Answer 12

1. Control eye (vestibulo-ocular reflex)
2. Controls head on trunk position (head +body controlled differently)
3. Maintains upright posture
4. Support Lower limb extensions during locomotion

Question 13

Vestibulo-ocular reflex (VOR)

Answer 13

Stabilizes image on retina when head moves

Question 14

What does vestibular system do during VOR

Answer 14

Sends info about how fast the head is moving

Question 15

What does occulomotor systems so during VOR

Answer 15

Uses info from vestibular to move eyes so the image is stable

Question 16

3 symptoms of vestibular system dysfunction

Answer 16

Vertigo
Nystagmus
Postural imbalance

Question 17

Vertigo

Answer 17

Sensation of you or the environment moving even though you are stationary
- BPPV

Question 18

BPPV

Answer 18

Benign paroxysmal positional vertigo

Question 19

Nystagmus

Answer 19

Involuntary eye movement (beating)

Question 20

Postural imbalance

Answer 20

Dizziness, falls, leaning

Question 21

What 2 dysfunctions often go hand in hand

Answer 21

Vertigo and nystagmus

Question 22

What is the preferred way to get sensory info

Answer 22

Vision

Question 23

Why did people adjust posture not to fall in room where wall moved but floors didn’t

Answer 23

Rely more on visual then mechanoreceptors we have for proprioception

Question 24

Evidence of relying more on vision

Answer 24

• beginnner typists look at their fingers
• beginner dancers look at their feet

Question 25

Parts of human eye

Answer 25

Optic nerve, iris, cornea, pupil, lens, retina, macula, fovea

Question 26

Neural components of the eye and vision

Answer 26

Retina, fovea centralis, optic disc, rods, cones, optic nerve (cranial nerve II)

Question 27

Retina

Answer 27

Light sensitive nerves at back of eye Receives images - sends to optic nerve - to brain

Question 28

Fovea centralis

Answer 28

- central vision, most objects seen here - provide brain with info about what is being seen and how to use it to complete motor skill

Question 29

Optic disc

Answer 29

- round spot on retina- passage of axons of retinal ganglion cells - transfer signals from photoreceptors to optic nerve

Question 30

Rods

Answer 30

Detect low light level

Question 31

Cones

Answer 31

Detect high light level, colours

Question 32

Optic nerve (cranial nerve II)

Answer 32

- from retina to brains visual cortex - transmission of sensory info to brain

Question 33

When light changes why does blindness occur

Answer 33

Switching from rods to cones or opposite

Question 34

How is the image refracted on the retina

Answer 34

Upside down and rotated backwards

Question 35

What does size of image on retina depend on

Answer 35

Distance from the eye

Question 36

3 techniques for investigating the role of vision in motor control

Answer 36

1. Eye movement recording 2. Temporal occlusion techniques 3. Event occlusion technique

Question 37

Eye movement recording

Answer 37

- tracks foveal visions ‘point of gaze’ - new vs experienced learner Ex) what person is looking at

Question 38

Temporal occlusion techniques

Answer 38

- stop video or film at various times then ask what they are focused on - spectacles with liquid crystal lenses

Question 39

Event occlusion technique

Answer 39

Mask view on video or film of specific events or characteristics and ask what focused on

Question 40

Monocular vision

Answer 40

One eye

Question 41

What is binocular vision important for

Answer 41

Depth-perception when 3 dimensional features are involved in situation

Question 42

Ex of when binocular vision important

Answer 42

Reaching- grasping objects Walking on cluttered pathway Intercepting a moving object

Question 43

What is often underestimated without binocular vision

Answer 43

Distances and size of objects

Question 44

Synonym for central vision

Answer 44

Foveal vision

Question 45

What is central vision

Answer 45

Directly in front Middle 2-5 degrees of visual field

Question 46

What does central vision provide

Answer 46

Specific info to allow us to achieve goals - size, shape, texture

Question 47

Examples of specific goals central vision allows

Answer 47

1. Reaching/grasping object - specific characteristics like size and shape and required to prepare, move and grasp 2. Walking on pathway - specific info to stay on pathway is needed

Question 48

What is peripheral vision detect

Answer 48

Info beyond central vision limits (upper limit of ~200 degrees)

Question 49

What does peripheral vision provide

Answer 49

Info about environmental context and moving limbs

Question 50

When we go through environment, how does peripheral vision detect info

Answer 50

Assessing optical flow patterns

Question 51

Optical flow

Answer 51

Rays of light that strike the retina

Question 52

Vision for perception

Answer 52

Central vision

Question 53

What is central vision anatomically referred to

Answer 53

Ventral stream from visual cortex to temporal lobe

Question 54

What is central vision for

Answer 54

Fine analysis of a scene (form, features, colour, texture) Typically available to consciousness

Question 55

Vision for action

Answer 55

Peripheral vision

Question 56

What is peripheral vision anatomically referred to as

Answer 56

Dorsal stream from visual cortex to posterior parietal lobe

Question 57

What is peripheral vision for

Answer 57

Detecting spatial characteristic of a scene and guiding movement Typically not available to consciousness (ex. Sport, driving a car) Can still get info (subconscious)

Question 58

What is perception referred to as

Answer 58

“Coupling” of vision and movement

Question 59

Example of perception in research

Answer 59

Results showed that spatial and temporal characteristics of limb movements occurred together with specific spatial and temporal characteristics of eye movements (eye before movement)

Question 60

Examples of when eyes move before limb movements

Answer 60

Catching a ball Picking up pen Putting key in keyhole

Question 61

needed for movement corrections

Answer 61

Vision as feedback Vision’s feedback role during movement

Question 62

What is the amount of time needed for movement corrections

Answer 62

Do not know amount of time to detect an error and make correction

Question 63

If speed is too fast or distance too short to allow any movement modification, what does success at catching the ball depend on

Answer 63

Initial hand position

Question 64

If person climbing stairs too fast to allow for foot position adjustments while foot on flight, what increases

Answer 64

Risk of falling

Question 65

What are the 5 roles of vision in motor control

Answer 65

1. Monocular vs binocular vision 2. Central and peripheral vision 3. Perception 4. Amount of time needed for movement corrections 5. Time to contact

Question 66

What situations does time to contact (optical variable) concern

Answer 66

- object moving to person must be intercepted (catch or hit ball) - person moving toward object needs to contact or avoid contact with object

Question 67

What provides info about time-to-contact

Answer 67

Vision, which the motor control system uses to initiate movement

Question 68

How does vision initiate movement

Answer 68

Automatic: specification based on changing size of object on retina - at critical size, requisite movement initiated (ex. Moving out of way of something coming at you)

Question 69

What is the motor control benefit to vision

Answer 69

Automatic movement initiation