adaptations to novel mechanical loads Flashcards
what is motor learning
set of processes that are associated with practise or experience and cause relatively permanent gains in the capacity for skilled performance
what are the basic properties of motor learning
- practise doesn’t guarantee motor learning
- learning doesn’t guarantee anything
- learning alters capability for performance
- learning produces relatively permanent changes in capacity for skilled performance
what is the law of practise (diminishing returns)
- performance improves rapidly at first and then more gradually later
- power or exponential decay processes
- rate is constant and depends on the size of the error
what is the saving of learning principle
rate of relearning a motor skills is faster (on average) than the rate the skill was initially learned
what is specialised transfer
closed skills that can be practised directly
- task and environment are predictable
what is generalised transfer
more difficult to practise directly and must transfer to some extent from practise to a game setting
what is the difference between near and far transfer
near transfer - practise conditions are similar to play
far transfer - ex: pulling weights to build power and strength to transfer to skating
what is the difference between discrete, serial, and continuous motor skills
discrete - well defined beginning and end (throwing a pitch)
serial - series of discrete skills to make more complicated skill (dance routine)
continuous - repetitive with no clear beginning or end (biking or running)
what is retention of learning
changes in the capacity for skills performance during a period with no practise
what is the difference in retention between discrete and continuous motor skills
discrete - brief periods without practise can lead to reduction in performance (use it or lose it)
continuous - performance is less likely to suffer during longer periods without practise (riding a bike)
what is motor learning
process of acquiring new motor skills or improving the performance of an existing skill
what is motor adaptation
modifying an existing motor skill with different conditions or equipment
what is the importance of motor adaptation
can adapt our actions for different environments, tasks, and behavioural contexts
adaptation allows the NS to maintain skilled actions across the lifespan
what is a sensory prediction error (SPE)
SPE = expected — actual sensory consequences of mvmt
(similar to internal models)
when is SPE high and low
high SPE = when novel load is applied
low SPE = when NS can predict outcomes
what is the benefit of high adaptation rate (learning fast)
in a CONSTANT environment
= low errors and more efficient
what is the disadvantage of high adaptation rate (where a low adaptation rate would be better)
environments with HIGH variability
- fast adaptation can cause errors (similar to washout - overadapt)
how are expected consequences calculated
efference copies of motor commands + internall (forward) model of body and environment
when error persists, forward model needs to be updated (critical for adaptation)
how generalisable is force field adaptation
decay in generalisation as you move further away from the learned direction
bell curve:
- peak in training conditions
- rapid decay on either side
- asymptotes around 90 degrees away
why is generalisation non existent when the spatial distance is >90 degrees away
need to use different muscle groups by the time the target is that far away
how do you maximise generalisation
random order different target directions
- engages different muscle groups
what do cerebellar patients display in the multi target condition
baseline mvmts - jerky, intentional tremor, dysmetria
early adapt - jerky and biased in direction of load
late adapt - little adaptation occurs
washout - little after effect deviations
retention also impaired
what is the difference between experiments done in patients with huntingtons, and controls
adaptation present in healthy adults and huntingtons (only impairs the indirect pathway of basal ganglia)
what is the relationship between cerebellar impairment and adaptation
negative relationship
- increased impairment = decreased ability to adapt
