Movement Control

Front 1

What are 2 sources of sensory information

Back 1

a)exteroceptive: info from environment outside of the body (vision)
b)proprioceptive or kinesthetic: info from within body

Front 2

Why are both sources of sensory info important do they both have to be present to make mvmt

Back 2

It is possible for mvmt in the absence of one but mvmt is degraded.
amount of accuracy decrement w/o these sources of feedback seems to be related to the duration of the mvmt where very fast ballistic mvmts are affected less.

Front 3

What are the two important functions of the sources of sensory info

Back 3

guidance of limb or body tragectory: homing in or fefining of the movemetn is made to complete the task

Front 4

Explain Open loop control system..baseball swing

Back 4

Baseball..
1)Input: ball coming towards you
2)Executive or mvmt control center
a)stimulus identification(evaluate environment)
b)response selection (decide whether or not to swing)
c)response programming (if decision to swing develop and initiate teh motor prgram for doin so
3)EFFECTOR
a)Motor program to swing is delivered to spinal cord and then to muscles, where contraction takes place
4)Output:bat swing

Front 5

Explain closed loop control..driving a car

Back 5

Driving a car...
1)Input: a turn in the road
2)Executive
a)stimulus identification (the environment)
b)response selection (decide whether to turn wheel slighty to left or right)
c)response programming (sends message to effector tells motor program to do so)and a desired state is sent to the comparator
2)Effector:
a)motor program carries out plan sends signal to spinal cor then goes to the muscles
4)output: mvmt of car takes place
5)actual state is sent as feedback to the comparoter feedforwards info to to executive which ends up being the input then cycle repeats again

Front 6

What are the main differences between open and closed loop systems

Back 6

a)open does not involve feedback
b)closed loop is continuous loop of info
c)nature of mvmt commands is partial for closed and complete for open
d)types of skills: closed is effective for continuous, long duration skills; open is effective for descrete skills

Front 7

Define the generalized motor program

Back 7

is a memory representation (long term) of a class of actions (kick,walk) that is responsible for producing a unique (variety diff spin diff feet)pattern of activity when it is executed.

Front 8

What are the major roles of the motor program

Back 8

1)define + issue commands to muscle to determine when, how forcefully, and which muscles to contract
2)organizes many degrees of freedom of muscles+joints into a single unit
3)to specify and initiate preliminary postural adjustments necessary to support the upcoming actions
4)to modulate the many reflex pathways to ensure that the movement goal is achieved

Front 9

What are some invariant characteristics of the motor program(does not change)

Back 9

characteristics consistant from 1 response to the next ie) relative timing..walking heel-to-swing..independent to overall speed and amplitude the % of time from heel to swing is the same

Front 10

What are some paramaters (change) in characteristics of motor program

Back 10

characteristics which vary from 1 response the the next..ie the specific requirements demanded by a particular action..way you hold a ball for diff pitch

Front 11

What is formula for Fitts Law

Back 11

MT=log2(2A/W) where Mt=movement a=amplitude(distance between targets) and W=width of target

Front 12

what can we conclude from fitts law

Back 12

a)movement time increases(longer) but only slightly, as the movement amplitude (distance between target) increases
2)mvmt time increases as the aiming accuracy requirement increawes, that is, as the target widhth decreases
3)mvmt time is essentially constant for a given ratio of mvmt amplitude(distance between target to width of target....as A goes up Mt goes up..as Width goes down Mt goes up and as accuracy goes up mt also goes up