R2G

Question 1

how much head rotation do we use for accuracy

Answer 1

100% of angular distance

Question 2

what encodes the postion of the hand relative to gaze and goal

Answer 2

dorsal premotor cortex

Question 3

what kinematics vary according to goals/contstraints of tasks

Answer 3

velocity
movement duration

Question 4

describe the motor planning pathway through the brain

Answer 4

visual cortex (to parietal and temporal) -> prefrontal cortex -> to cerebellum/BG and motor cortex -> brain stem -> spinal cord

Question 5

describe the ventral visual pathway

Answer 5

perception and object recognition (what)
visual cortex -> temporal cortex

Question 6

what descending path is used for reach

Answer 6

midbrain and brainstem

Question 7

what descending pathway is used for grasp

Answer 7

primary motor cortex and corticospinal tract (processed parallel)

Question 8

what aspects of the brain help to determine grip

Answer 8

visual cortex
parietal lobe
premotor cortex

Question 9

what are the different types of grips

Answer 9

hook
spherical
cylindrical

Question 10

describe anticipatory shaping of grasping patterns

Answer 10

pre-grasp is determined by intrinsic and extrinsic properties of object
grip size is proportional to object (max aperture -> reduced to match)

Question 11

what are the phases of grasp, lift, and release

Answer 11

contact
grip and load
lift release

Question 12

what happens if you have a ventral stream lesion

Answer 12

no conscious perception or dimension of objects, but able to pick up objects with great adeptness

Question 13

what happens if you have a dorsal stream lesion

Answer 13

both sensory and movement related deficits

Question 14

what does the medial superior temporal region do in movement planning

Answer 14

planning of smooth pursuit

Question 15

what does the posterior parietal cortex do in movement planning

Answer 15

encodes orientation for R2G

Question 16

what happens with reaching with no vision or impaired vision

Answer 16

reach times are shorter
larger constant errors
timing of grasp is not effected

Question 17

what is hicks law

Answer 17

having a longer distance from the target and a smaller target size both increase reaction time

Question 18

what SS info is needed for grasp

Answer 18

accuracy in grasp and adaptation object contact, grip forces, detection of slipping, cutaneous inputs, and finger position

Question 19

if you reach without SS info, what can happen

Answer 19

drift
vision can slightly compensate
conplex/repetitive/novel tasks may not be able to happen

Question 20

what are 3 factors that contribute to sensorimotor processing in UE reaching and grasping

Answer 20

individual
task
environment

Question 21

where does R2G fit in the ICF domain

Answer 21

within body structure and body fx and in activity and participation

Question 22

what are the four key elements of R2G

Answer 22

• locate the object (visual regard)
• reach (PC and moving UE in space)
• grasp (grip formation, grasp and release)
• in-hand manipulation (fine motor)

Question 23

during locating central objects what moves

Answer 23

eyes only

Question 24

during locating peripheral objects, what moves

Answer 24

eyes and head (neck muscle activated first, but eyes actually move first)

Question 25

in children with hemiplegia, if they don't have vision and an intact motor system, how is motor planning and execution affected

Answer 25

they cannot develop or execute a movement successfully

Question 26

pointing has a ______ acceleration but a __________ deceleration because we move as one unit

Answer 26

long short

Question 27

describe the dorsal visual pathway

Answer 27

localization (where) visual cortex -> parietal cortex

Question 28

where does a motor plan go to for modification and refinement

Answer 28

cerebellum and BG

Question 29

if you perturb one component of R2G what happens to the other

Answer 29

the other is affected as well, despite them being modulated by different tracts

Question 30

what are some task/environ related demands that influence grasp performance

Answer 30

weight of object, object size, shape and texture inertial resistance provided by intrinsic stiffness of UE and hand

Question 31

what is translation (in hand manipulation)

Answer 31

ability to move objects from fingertips to palm or palm to fingertips

Question 32

what is shift (in hand manipulation)

Answer 32

ability to move an object in a linear manner with fingertips

Question 33

what is rotation (in hand manipulation)

Answer 33

ability to turn an object around with fingers and thumb or turning object from end to end

Question 34

what does the premotor cortex do in movement planning

Answer 34

codes body movement makes plan to be sent to motor cortex

Question 35

is reaching across midline faster or slower? why?

Answer 35

slower you are reaching into contralateral visual hemi field which increases processing time

Question 36

T/F: reaction time decreases with practice

Answer 36

true