Response Planning - Open Loop Control Flashcards
What does info processing look like in open loop control
Stimulus identification
Response selection
Response programming
Good for describing rapid movements
Do not have time to react to feedback
Describe open loop
Output has no influence or effect on the control action
Feedforward - input controls the output and is used to respond in advance of an expected output
What is a motor programme
An abstract representation, that when initiated results in the production of a coordinated movement sequence
Motor programme selected
Motor neurons
Muscle contraction
Where does evidence for motor programmed come from
Reaction time studies
Deafferentation studies
EMG studies
Explain reaction time as evidence for motor programmes
As task complexity (reaction complexity) increases, reaction time also increases.
Only thing that could be making RT longer is longer time to programme the more complex movement.
Still a simple RT, just a more complex response required
Explain deafferentation studies as evidence for motor programmes
When receiving (not sending) signals, from afferent.
Deafferentation is the removal of that sensory information.
Studies on people who have lost feedback from injury ext.
Found they can still produce/learn new movement.
In order to move don’t rely on feedback, info to move come from info stored centrally.
Explain central control mechanisms as evidence for motor programmes
Cat with a midbrain cut
If electricity stimulate spine, cat begins to walk
Spine has pattern generators, neurons that facilitate flexors/extensors in cyclical pattern
Explain EMG studies as evidence for motor programmes
Usually when look at EMG of a single muscle movement, triphasic movement
E.g wave for triceps, then biceps, then wave for both
(Agonist, antagonist, both)
Found that when when they stopped the movement, waves almost identical - ag and antagonist still active in blocked trial
Antagonist = not a reflex action, instruction was sent in advance at once
Less so when movement slower, for rapid movements therefore, all movement is programmed and sent in advance
Explain inhibiting rapid actions
Once demand sent out for rapid movement, cannot then recall it
Would have to sent stop signal half way through the reaction time
List the problems with motor programmes
Storage
Novelty
Degrees of freedom
What is motor equivalence
Can transfer style to other parts of body
E.g handwriting
What is a generalised motor programme
A motor programme whose expression can be varies depending on the choice of certain parameters
Shmidt
Explain generalised motor programmes
E.g kicking a football
One program - proximal to distal at hip, knee, ankle
Parameter 1 = how far back lift up to 40 degrees in steps of 1 degree
2 = hip rotation
3 = duration/ speed
4 = leg (left or right)
Possible kicks = 1,600
What is the impulse - timing hypothesis
Motor programme - motor neuron - muscle
The role of the MP is to tell the muscle when to switch on and how much force to produce
Give the impulse equation
Impulse = a change in momentum
Force x time
f = ma
M = (v-u) / t
Ft = mv - mu
Explain the force time graph
Impulse is area under curve
Area = change in momentum
As area is force x time
What factors effect impulse
Factors that effect force and timing
= invariant features
List the invariant features
Order of events
Relative timing
Relative force
How does order of effects effect impulse
Keep same order
What are the parameters of GMP
The things that we do change
Overall duration, can vary time of movement
Overall force, can vary need more to go faster
Muscle selection
Explain the overall duration parameter
Motor programme contains:
Order of events
Relative timing
Overall duration defines the speed
Explain the overall force parameter
Motor programme contains:
Relative force
Overall force depends on:
Requirements e.g throwing task
Explain the muscle selection parameter
Which part of body will carry out action
