motor learning Flashcards
define motor control
nature and cause of movement
what is the movement
how is movement happening
Define motor learning
acquisition and modification of movement
how do we learn new movement
how can we teach new movement
systems model of motor control
components working together : BG cerebellum sensory receptors muscles cerebral cortex central pattern generator
Within NS
Different components for movment
Systems model means componetns work as a team
Cortex signals to cortical spinal tract and down the SC to muscles for movement
Interneurons called central pattern generators have a role in maintaining movement
Can output to muscles
Sensory info constantly coming back through sensory pathways + parallel pathways in cerebellum
Give direction through cerebral cortex direction to muscles whichc muscles to recruit and when
Complicated
motor control
sequences of events
intention –> activation –> movement
Activation
Intention
Sensory input selection
Stimulus recognition and memory mechanisms
Response selection: Motor programs (“Grammar of action” = set of rules between cognition and action)
Programming: Planning (sequence), parameter specification
(force, direction)
Postural control: Visual, somatosensory, vestibular
Movement initiation
Feedback: Sensory, visual, cognitive, emotional
Feedforward: Sending of signal ahead of the response, prepare the system for input
phases of motor learning
cognitive - early
associative - intermediate
associate environment cues with mvmt improve motor skills
autonomous - final - automatic
- high rate of error initially then it slows
repetitive repetitive engagement in new experiences
cognitive phases
phase 1
phase 2
Phase 1: Understanding
goal of task
movements that will bring about the accomplishment of the goal
the strategy that will work best to produce the desired movements
Phase 2: Selection of an appropriate motor program
Produces movement for the first practice trial
Response specifications determined
Motor command implemented
Movement sequence executed
association
Hebb’s rule
Hebb’s Rule:
When an axon of Cell A is near enough to excite Cell B and
repeatedly takes part in firing it,
a growth process takes place so that A’s efficiency in firing B is increased.
cells that fire together wire together
associative / intermediate phase
Movements fuse into well co-ordinated patterns extraneous movements eliminated
gross errors gradually attenuated
components integrated
Cognitive involvement remains high
Longest phase, lasts a variable amount of time depending on task
Unstable: can be influenced
PT can optimise this phase but it needs intensity
autonomous phase
Spatial and temporal factors become highly organised
Component processes become increasingly autonomous or automatic
Conscious introspection can be
detrimental
“paralysis from analysis”
Physiotherapy implications
progress: speed accuracy trade off
changing the speed accuracy trade off is a sign of motor learning
progress “impedance control”
freeze redundant degrees of freedom
release degrees of freedom
use external forces rather than resist them
process orientated model
adequate feedback and knowledge of results
opportunity to practice
adequate design of the learning situation
feedback
sensory information that is contingent on having produced a movement
intrinsic / extrinsic
Feedback from the movement performed is compared with the plan or desired outcome \_\_> Discrepancies --> Motor program or recall schema is modified --> Movement is attempted again
predictive control
sensory feedback has delays reactive predictive control feed-forward : predict the sensory consequences learn from errors update motor command
cerebellum
feedback intrinsic and augmented
intrinsic Intrinsic
“Task-intrinsic”, “inherent” Sensory-perceptual information in performing a skill
Natural / inevitable consequence
of movement
Sources: vision, vestibular,
auditory, tactile, proprioceptive
Augmented
Adds to intrinsic feedback External source
Therapist
Technology Essential where intrinsic feedback is impaired
knowledge of results - outcome
knowledge of performance
movement characteristics
augmented feedback: timing
concurrent feedback
terminal feedback
concurrent Feedback as the patient performs the task Directs attention away from intrinsic feedback
Good performance Poor retention
Useful if difficulty using intrinsic feedback
Slight delay between task and feedback
Self-evaluation of outcome
Performing different skills can interfere (e.g. dual cognitive / motor task)
verbalisation
self feedback
Important in early phase
Talk through action prior to or after
Allows arrival at a conceptualisation of task to be learned
Verbal labelling of error is common
instructional techniques
therapist feedback
Used to enhance the learning rate and ultimate proficiency level
Visually: demonstrate
Audibly: give instructions
Manually: used by almost all physios
may enhance initial retention but not long-term
Purpose: Direct the learner to specific / relevant stimuli Reduce amount of irrelevant stimuli Control the presentation of information (timing, amount of material)
role of PT
Movement prescription (diagnose problems, present alternative or solution)
Careful observer of movement
Provide appropriate feedback
practice
Necessary condition for motor improvement Physical – movement
Mental – cognitive
How much?
THOUSANDS of repetitions may be necessary
Task-specific training: consider motor control – sequence of events Types of practice
Massed vs Distributed
practice schedule
mass practice
Same thing over and over Initially faster learning /
performance (and therefore reward)
Better for closed skill
distributed practice Try things lots of different ways Less initial progress
More frustrating More generalisable Better transferability
self controlled practice
Improves learning
Active involvement of learner
Learners are effective in selecting practice conditions conducive
to learning
Self-Controlled feedback improves learning
adequate design of learning situation
Transfer of training: Training on one task transferring to training on
another task
(gym v home / ward environment) (gym v football pitch)
environment
promote safe independent practice
priming nervous system for learning
Aerobic exercise (physical activity) enhances neural plasticity (learning) by:
Increasing blood flow to the brain
Facilitating the release of neurotrophic factors (BDNF)
Improving brain health (brain volume)
exercise - goal based aeorbic exercise
increased synaptic strength
increase NTS
increase receptor density
increased dendritic spine formation
improved brain health increased trophic factors increased blood flow increase immune system increase neurogenesis increase metabolism
strengthened circuitry BG cortex thalamus cerebellum brainstem
increased functional and structural connectivity in the brain.
