Grasp & Reach

Question 1

Response to Target in Peripheral Vision (3)

Answer 1

1. Eyes mm activated
2. Neck mm activated
3. Eyes move first, then the head moves, the eyes reach the target before the head stops moving.

Question 2

_______1_______ signals from eye muscles contribute to the ability of ___2___ targets in extrapersonal space.

Answer 2

1. Proprioceptive
2. Localize

Question 3

Inputs of 2 parallel pathways for the visual system.

Answer 3

1. Perception and object recognition [visual cortex to temporal cortex]
2. Localization [visual cortex to parietal lobe]

Question 4

Stream Pathway:

• Visual to partietal cortex
• Action-relevant info for reaching including object position, structure, and orientation
• Mediates sensorimotor transformations

Answer 4

Doral Stream Pathway

Question 5

Stream Pathway:

• Visual to temporal cortex
• Conscious visual perceptual experience
• Perceptual identifications of objects

Answer 5

Ventral Stream Pathway

Question 6

Somatosensory information is not required for __1__, ___2___, or ______3______ arm movement initiation or execution. _______4_______ with complex tasks results when visual input is removed.

Answer 6

1. Fast
2. Simple
3. Nonrepetitive
4. Incoordination

Question 7

Input: essential for control of grip forces

Answer 7

Cutaneous afferent input

Question 8

Cortex: critical for control of grasp

Answer 8

Somatosensory cortex

Question 9

2 systems that allow for reach and grasp to be updated online

Answer 9

1. Visual
2. Somatosensory

Question 10

Normal movement requires the following structure for

1. Intact primary motor cortex
2. Intact cerebellum
3. Intact midbrain/brainstem

Answer 10

1. Important for precision grip over power grip
2. For coordination of reach/grasp and anticipatory postural control
3. For proximal mm in reach

Question 11

Type of Grasp: finger and thumb pads direct force toward palm

Answer 11

Power Grip

Question 12

Type of Grasp: Finger and thumb direct forces to each other

Answer 12

Precision Grip

Question 13

2 requirements for successful grasp

Answer 13

1. Hand must be adapted to shape, size, and use of object
2. Finger movements must be times in relation to transport

Question 14

Grip size changes primary by movement of the ___1___. Grip size is ___2___ than width of target and scaled __3__ just before contact with the object.

Answer 14

1. Fingers
2. Larger
3. Down

Question 15

Term: object’s location with respect to the body

Answer 15

Extrinsic (contextual) properties of object

Question 16

Define bimanual skill

Answer 16

When one hand performs a simple task while the other performs complex task the pattern of movement of the hand doing the simple task has some elements of the complex task

[even more pronouned when non-dominant hand is doing the complex task]

Question 17

When the UE is affected by a brian lesion the contralesional side is ____1____, BUT the ipsilesionside is usually ___2___ ____3____.

Answer 17

1. Affected
2. Mildly
3. Affected

Question 18

When both hands perform at the same time the ____1____ limb assume a temporal pattern similar to that of the _____2_____ limb. As with controls, both hands reach the target at the same time but the _____3_____ does not get faster when both hands move together.

Answer 18

1. Non-paretic
2. Paretic
3. Paretic

Question 19

If the goal is smooth, coordinated movement, there is some evidence that ____1____ activities can help the affected arm. However, this gains may not transfer to _____2_____ conditions. If the goal is to increase speed of movement of the affected arm, ____3____ movement are probably not a good idea.

Answer 19

1. Bilateral
2. Unilateral
3. Bilateral

Question 20

4 Factors of increased reaching movement time with age

Answer 20

Due to changes in

1. Sensory/perceptual systems
2. Central processing systems
3. Motor systems
4. Arousal/motivational systems

Question 21

Changes in reaching coordination with age (3)

Answer 21

1. Slowing in target approach and deceleration phase
2. More movemtn adjustments due to less open loop and more closed loop activity
3. Decreased hand steadiness

Question 22

Changes in grasping with age (3)

Answer 22

1. Decreased manual dexterity
2. Longer times need to manipulate small objects
3. Larger grip forces with less ability to adapt to changes

Question 23

When presented with unpredictable conditions for reaching and grasping, older adults pick the most ______1______ approach

Answer 23

1. Conservative

Leads to longer approach time and use of standardized coordination patterns

Question 24

In older adults performance can be _____1_____, particulary with more ____2____ tasks.

Answer 24

1. Improved
2. Complex