CH 8- COORDINATION

Question 1

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coordination

Answer 1

involves the constraints that exist among multiple moving effectors such that variables being coordinated obey allegiance to a simple function

-meaning there are muscles/effectors that are activated to do a particular effect + there are issues that can exist between those different effectors
-when those issues arise, we have an uncoordinated situation
-using different limbs concurrently

Question 1

interference

Answer 1

temporal structure of actions being coordinated

-interference occurs when there are problems with muscles/effectors being coordinated

Question 2

daily activities are also called ____

Answer 2

acts of daily living (ADLs)

Question 3

daily activities (ADLs) without interference

Answer 3

-using a knife + fork
-playing piano
-walking + chewing gum
-throwing + kicking

Question 4

what do ADLs without interference suggest

Answer 4

suggest the existence of interlimb coordination processes that facilitate biologically important skills but impede arbitrary ones

Question 5

example of biologically important skills

Answer 5

I need to eat every day so I will learn to use cutlery

Question 6

example of arbitrary skills

Answer 6

I don’t always tap the rhythms of nursery rhymes with my 2 hands so I probably won’t be coordinated unless I practice

Question 7

Peters, 1977

Answer 7

-looked at 100 subjects + considered whether they could recite a nursery rhyme (using neck muscles) at same time as tapping their hands to a different rhythm
-ALL subjects were unsuccessful
-interference occurred; because they were unsuccessful, they were unable to demonstrate coordination

Question 8

Summers + colleagues, 1993

Answer 8

-asked subjects to tap different rhythms on each hand
-polyrhythm
-bimanual setup
-subjects were unable to do these movements without interference

Question 9

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discrete

Answer 9

-definite start + end
-often performed quickly
-important in preplanning + body movement organization

Question 10

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continuous

Answer 10

-fairly arbitrary start + end; depend on context
-pre-movement planning is less important
-more time to receive feedback + detect errors (+ correct them)

Question 11

coordination in discrete tasks

Answer 11

-one of the key attributes to coordination in aiming/reaching/grasping tasks is using saccades (because of the tight connection between head + eye movement)
-saccades allow person to quickly identify stimulus

Question 12

coordination in discrete tasks- vestibular-ocular reflex (VOR)

Answer 12

-there are opposing motions of the eyes + head that helps us with this ability to coordinate our eyes + head
-a rotation of the head is detected, which triggers an inhibitory signal to the eye muscles on one side + an excitatory signal to the muscles on the other side; the result is a compensatory movement of the eyes

-the eyes compensate for the head moving
-stabilizes visual image on the retina
-IPSP: inhibitory postsynaptic potential
-EPSP: excitatory postsynaptic potential

Question 13

coordination in continuous tasks

Answer 13

Experiment A:
-moving a second limb along with another that is already moving has pros + cons, depending on task
* (1) writing name on chalkboard with nondominant hand at usual speed but backward (mirror image)

-coupling of hands, even though nondominant is more uncontrolled than dominant, characteristic pattern emerges
* (2) same but concurrent with dominant handwriting normally (opposite directions)

Experiment B:
-the tendency to couple limb movements depends on the tasks + effectors involved
* (1) draw clockwise circles on floor with right foot then draw the number 6 in the air with right hand at the same time
* (2) try again, then use left hand to make the circles
* (3) do all 3 actions in the counterclockwise direction

Question 14

Saeb, Weber, + Triesch, 2011

Answer 14

-had monkeys looking straight ahead (both eyes + head straight ahead); subjects suddenly experienced an unexpected target in periphery of their visual field
-there was a different timeline for eyes, head, + gaze to get to stimulus
-eyes win by getting to position first; eyes quickly orient to unexpected target, then stabilizes
-gaze (the fovea) is quick to follow; retains vision where you are actually paying attention to + continuous to look at the object
-head takes the longest to get to stimulus

-besides these different timelines, this shows that eyes + head have very opposing timing; they are coordinated but by opposite timing
-eyes have reacted so quickly that head must work to catch up; by the time the head gets to that position, the eyes have already left

Question 15

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reaching + grasping movements

Answer 15

-reach + grasp actions are coordinated in time + space
-maximize efficiency in terms of economy of effort + time
-there is a file (GMP) for reaching + grasping movements; these files coordinate the relative timing between eyes, head, + hand
-unimanual movement

Question 16

reaching + grasping movements- parameters we give to GMP to modify case by case

Answer 16

-overall movement duration
-movement size

Question 17

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temporal planning

Answer 17

reaching + grasping components:
-transport: move hand to general vicinity of target space
-grip-formation: prepares hand to capture object; influenced by intention of what will be done with object
-aperture: widening or narrowing of grip
-grip formation is modified based on object identified in front of me

Question 18

aperture

Answer 18

widening or narrowing of grip

Question 19

Jeannerod, 1981, 1984

Answer 19

-study found that reaching + grasping tasks have 2 parts to them: transport + grip
-first acceleration, then deceleration
-when grip was the widest (max grip = 75% overall movement ), then make grip smaller as you actually grab the object
-time of peak grip aperture coincided with point of peak deceleration of risk at 75% overall movement

Question 20

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spatial planning

Answer 20

-spatial variability increases if same movement distances are completed in progressively shorter times
-rapid reaching tasks or at comfortable speed with/without vision
* with vision: aperture widened with reduced duration
* without vision: aperture widened further
-subjects compensate for anticipated increased spatial variability in limb transport by increasing grip size, thus maintaining constant success rate by adjusting tolerance for spatial error as needed

Question 21

Yamanishi, Kawato, + Suzuki, 1980

Answer 21

-subjects concurrently doing tasks with both hands (bimanually) with visual metronomes on either L/R side, which gave tempo either in phase (in symmetry) or out of phase (anti-phase/asymmetry)
-subjects tapped L/R fingers in time with L/R visual metronomes that clicked at various offsets
-when beats of metronome were at 0 or 360 (in phase) subjects did best- least amount of error + least deviation
* anti-phase beats occur at 180
-in-phase + anti-phase patterns are performed with greater accuracy + more stability than any other phase relation

Question 22

directional preference

Answer 22

when we have a pattern/way we contract our muscles that we prefer over another; dominant pattern of movement
-when both limbs move in same direction
-stronger coordination modes occur for movements in same direction
-different coordination modes are not dependent on specific muscle groups used
-the spatial orientation of the actions are significant

Question 23

interlimb pairings
homologous

Answer 23

same limb pairs
ex: L + R arms, L + R legs

Question 24

interlimb pairings
ipsilateral

Answer 24

same side limb pairs
ex: L leg + arm, R leg + arm

Question 25

interlimb pairings
contralateral

Answer 25

diagonal limb pairs
ex: L leg + R arm, L arm + R leg

Question 26

Kelso + Jeka, 1992

Answer 26

-studied phase variability for interlimb pairings:
-limbs move either in same or opposite directions
-limbs moving in same direction demonstrate more stable patterns than limbs moving in opposite directions
-only true for upper + lower limb combinations, which were more stable for contralateral pairs than ipsilateral pairs

Question 27

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social coordination

Answer 27

the actions of 2+ people are choreographed with a specific objective of creating something together that could not be achieved individually
-ex: ballet duet or synchronized dive

-predetermined scripts describe a play in football or a dance, but require considerable practice before acceptable coordination is achieved between athletes, actors, dancers, + musicians
-plans for action that describe the order + timing of events must be invariant with the parameters substituted as needed
-visual information, spoken conversation, + group synchronicity may be influential

Question 28

Muller study

Answer 28

-visual speed manipulation influences gait
-used an endless hallway virtual reality simulation to evaluate the role of vision on gait transitions (going from walking to running + running to walking)
-when visual feedback matched the treadmill- feedback was normal for the subject + they matched this in their transition time
-when visual feedback was slower than the treadmill- resulted in sensation that gait was slower than actual + made subject feel like they were walking slower, impacted gait transition
-when visual feedback was faster than the treadmill- resulted in walking quicker, took longer to transition into running

Question 29

summary

moving parts must be ____

Answer 29

organized

Question 30

summary

aiming movements involve coordination of ____, ____, + ____

Answer 30

eyes, head, + hands

Question 31

summary

reaching + grasping represents what type of movement

Answer 31

discrete

Question 32

____ tasks have an influence on Fitts’ paradigm, pending ID

Answer 32

bimanual

Question 33

____, cyclical actions can be impacted by coodination

Answer 33

continuous

Question 34

phase transitions may occur due to ____

Answer 34

destabilization of a pattern

Question 35

Pre-movement planning is more important for discrete/continuous

Answer 35

Discrete

Question 36

Continuous or discrete is quicker

Answer 36

Discrete