Motor Control And Learning Flashcards
What is motor control
Field of scientific study - seeks to determine principles and mechanisms that govern how we PLAN and EXECUTE movement
Examples of motor control
- learning new movements during development (child)
- learning new movements as an adult (learning to play tennis) “skill acquisition”
- injury that prevents normal/desired movement (spinal cord injury, Parkinson’s disease)
2 different kinds of neutrons
- sensory neuron (afferent)
- motor neuron (efferent)
What is a motor unit
A motor neuron and all the muscle fibres it innervates
- each muscle fibre innervated by a single motor neuron
- each motor neuron innervates many muscle fibres
Two extreme types of movements? Any relationship ?
- reflexes
- voluntary movements
- there’s a continuum - not a dichotomy between these extremes
What is the stretch reflex
- Muscle spindle detects magnitude and rate of stretch
- excitation of synergists to assist in bringing joint angle to original position
- inhibition of antagonist to allow stretch to be corrected
- reciprocal inhibition
Characteristics of reflexes
- fast
- relatively simple
- somewhat flexible
Reflexes in rehabilitation
- spinal circuits may operate below the level of injury/lesion
- can induce repeating movements via reflex pathways in some patients
- useful for cardiovascular health and perhaps locomotion
Voluntary movements
- goal directed (intentional)
- multiple areas contribute to movement planning
- commands sent via m1 to spinal cord
- huge flexibility of the tasks that can be performed
Characteristics of voluntary movements
- speed varies
- highly complex to simple(highly complex tasks can be performed relatively easy)(processing of movement plan is done subconsciously)
- highly flexible
Is sensation essential for normal movement ?
- we move to interact with world
- therefore need to sense environment to move effectively
- use our sensory systems to get information about our environment
- sensori-motor integration
- need to consciously perceive sensory information to use it
Perception vs. sensori-motor integration
- conscious perception involves the awareness of a stimulus
- only a small percentage of sensory signals picked up by the body are consciously perceived
What is perception
- accurate perception of the world requires processing and experience
- it’s not necessary for a signal to be fully perceived for it to contribute to the control of movement
- perception is not always accurate (can be creative/predictive)
Vision
- crucial sensor for external events
- also provides important information about our own movements
Vestibular apparatus
semicircular canals
otolith organ
functions?
-Provides information about head movements and head tilt
-semicircular canals: respond to angular acceleration in three planes
-otolith organs: respond to linear acceleration
Functions: linked with vision
Example of body receptors
Muscle, skin, joints
Body receptors (hint: muscle spindles, golgi tendon organs, other receptors)
- muscle,skin,joint
- length (and velocity) receptors (muscle spindles)
- tension receptors (Golgi tendon organs)
- other receptors provide information about skin pressure ,touch,joint deformation etc
Properties of sensory receptors (hint: what do they provide?)
- provide incomplete information (need to integrate information from various sensors and past experience for accurate perception)(implications for timing)
- may influence behaviour without conscious perception
Roles of sensory information in motor control (hint: 4 main roles)
- assess environment - decision making
- relatively direct contributions to muscle activation (reflexes)
- crucial for planning the details of movements
- essential to make corrections to inaccurate movements (online or next trial)
what is sensory information essential for? where does sensory information come from/why?
how many main roles does sensory information have?
- essential for normal movement however we generally don’t perceive this information
- sensory information comes from a number of varied sources to provide different types of information
- sensory information has 4 main roles in contributing to human movement
Role of models in scientific study (hint: 3 roles)
- models allow scientific theories to be visualised and understood
- simplify complex systems to concepts we are more easily able to deal with/process (often use everyday analogies/examples)
- provides basis for further experimentation on the model or parts of the model rather than concerned with the complexity of the underlying system
Information-processing models
(hint: origins? , aim? , usefulness?, analogies
- origins in psychology 1940s/70s
- aimed at answering practical questions e.g physical education or skill acquisition
- usefulness of information processing model
- allowed human motor control situations to be thought of as a computer
- simplifies this process for clearer understanding of how we perform movements
Central processing stages
Serial processing of information
-perceiving, deciding , acting
What are the three processing stages of information processing models
Give an example of each
Perceiving - obtaining relevant information about the task (self, environment)
Deciding - choosing a response from a range of alternatives
Acting - organising and executing the selected response
What are the approaches of the three processing stages of information processing models
Perceiving and deciding : traditional psychology approach
Acting: recent neurophysiological approach
What is perceiving
-accurate perception of the world requires processing and experience (expert vs novice performers)
- perception is not always accurate
- multiple sources of sensory information can conflict/cause ambiguity
How does perceiving benefit experts
Experts can use precontact information to make decisions about their responses
-experts can use information from proximal body parts for decision making (timing implications)
What is deciding
-depends on accurate and relevant sensory processing
- need to draw on previous experience to select the best response
- processing speed limitations
How does reaction time play a role in deciding
- reaction time is an important type of measurement to assess principles of motor control
- can be very simple (SRT) or choice (CRT)
- provide a stimulus, measure a time to respond
Decision making in deciding
- the more options there are to decide between, the longer it takes to react
- skilled performers have a greater range of options
- can also decide which options opponents most likely use
Conflicts in deciding
- it takes longer to react to stimuli that don’t usually occur together
- conflicts in stimulus increase processing time
- stroop task
What is acting
- organising and executing the movement commands (which muscle to contract, timing of contractions, keep opposing muscle quiet)
- complex process that may involve multiple areas of the nervous system
Complexity with acting
- acting also depends on complexity of task
- reaction time used to show more processing used up in movement execution for difficult tasks than others
- index finger flexion - extension task
Acting and resources
Amount of resources needed to organise movement depends on skill/ experience
What are the implications when we perform poorly
- not just the mechanics/techniques
- perception/decision making important
- can it be trained?
An info processing approach to human motor control
- models help us to simplify our understanding of complex concepts using everyday analogies
- perceiving: accurately process relevant sensory information
- deciding : make an accurate decision based upon the sensory information that has been perceived
- acting: implement a motor plan that can best respond to the decision
What are two examples of motor changes through the lifespan
Maturation/ development
Ageing
What are the developmental milestones of motor development 0-2 years
- primarily concerned with skills of survival
- posture, locomotion, reaching and grasping
What are the two main principles of motor development and what age
0-2 years
- cephalocaudal principle
- proximodistal principle
What happens with motor development >2 years
- develop a range of fundamental motor skills that form the basis for specialised adult motor behaviour
- locomotor skills (walking running jumping)
- non locomotor skills (throwing kicking striking catching )
What occurs in the running stage of motor skills development and what age
Initial 18mo-2yrs
-no flight phase
-short leg swing
-arm swing horizontally
Elementary:
-limited flight phase
-more arm swing
-increase stride length
Mature(4-6yr old)
-definite flight phase
-max stride length
What occurs in the initial stage of throwing for motor skills development
- mainly elbow
- trunk perpendicular
- feet stationary
elementary stage of throwing in motor skills development
- increased shoulder rot
- leg on same side
mature throwing stage in motor skills development
age?
boys, 12 years
- leg on opposite side
- trunk rotation
what neuromuscular changes occur in the visual system
- comprehensively developed by birth
- visual acuity improves with age during childhood
- 10 yr for stationary, 12 yr for moving objects
neuromuscular changes in the kinaesthetic/vestibular system
- comprehensively developed by birth
- 8yr for precise kinaesthetic judgements
neuromuscular changes in muscles
- get larger and affect our movement patterns
neuromuscular changes: changes in reflex system
primitive reflexes
- protection and survival
- birth to 3-4 months
- sucking reflex, moro reflex
postural and locomotor reflex changes
- preparing nervous system pathways
- 2 to 12 month (postural)
- e.g body righting, neck righting, parachute reflexes
- birth to 4-5 month (locomotor)
- e.g walking, swimming reflex
information processing in children/adolescents
PERCEPTION
- maturation of perceptual skills (8-10yrs) continues after sensory system has matured structurally
- more complex perceptual judgements take longer to develop (stationary vs moving objects)
- tasks requiring visual-kinaesthetic integration develop simultaneously with separate maturation of visual and kinaesthetic systems (hitting a ball)
what are implications for HPE teachers
?
- objective method of monitoring motor development to detect any movement
- provides information for teachers
- can examine neurophysiology to determine underlying mechanisms
changes in balance and posture: what is postural sway?
- 40% of vestibular receptors lost by age 70
- less cutaneous receptors and less sensory neurons innervating receptors
changes in balance and posture: what is recovery
- weaker, smaller muscles
- fewer motor neurons innervating muscle fibres
changes in balance and posture: extra examples
- poorer vision
- altered gait
- increased use of medication
changes in more complex motor skills?
- complex tasks deteriorates with aging
- last in, first out rule (CRT vs SRT)
- however, skills can be learned and improved in elderly
changes in the visual system for elders
- visual acuity, sensitivity to glare and contrast decline
- narrowing visual field and difficulty with low light
changes in kinaesthetic/vestibular system for elders
-loss of balance, sensitivity to touch, vibration, temperature and pain
changes in muscle in elders
- reduced size, number of motor units (fast twitch)
- activation of motor units becomes variable
implications for exercise physiologists?
- regular exercise
- regular practice
what is typical child and adolescent development characterised by
- types of movements they exhibit (motor development milestones)
when do perception, decision, and action stages improve
-from childhood to adolescence
what do elderly exhibit in the quality and complexity of their motor skills
- reversal
- however, this reversal can be slowed or complex skills can be learned with practice
what is motor learning
- relatively permanent change in the control elements of the nervous system that occurs as a result of practice and not attributed to maturation
- not directly observed or measurable (we measure performance instead)
how do you measure motor behaviour (performance)
- measuring of movement or outcome (error rate, #correct responses, #goals, time , kinematics, muscle activity)
how do you measure motor behaviour (learning)
- retention test
- transfer test
what is plasticity
- brain is highly malleable
- changes in synapse efficiency/connections
- changes in cortical representation
what changes occur in sensory reception of experts
- no changes in sensory receptors (vision)
what changes in perception occur with skill (experts)
experts are better at recognizing patterns and predicting upcoming events
what changes in decision making occur with skill (experts)
experts make decisions faster and better
what changes in acting occur with skill (experts)
experts perform better as well with high efficiency, repeatability and accuracy.
what is the (verbal) cognitive phase of motor skill acquisition
- learning the new task’s demands
- thinking, planning and comprehension
- explanation and demonstrations are very important
what is the associative phase of motor skill acquisition
- development and fine tuning of the control pattern
- practice is essential in this phase
what is the autonomous phase of motor skill acquisition?
- automatic initiation of movement patterns
- selective and global focus
- control programs are ingrained (habits)
why is feedback a factor that affects learning
- effective practice requires feedback of the movement to promote learning
- Knowledge of results (KR)
- Knowledge of performance (KP)
- both internal and external sources
It is important that feedback is..
- compared to previous performances
- specific to the activity/skill being performed and to the performer
- in manageable amounts for the performer to take in
- linked to goals of the movement/outcome
how does type of practice affect learning practice
- length of rest intervals (massed vs. distributed)
- variable (multiple tasks) vs. constant (one task) practice
what are performance curves?
- learning is a relatively permanent change in our nervous system that is indirectly inferred from changes in performance
function of semicircular canals in the vestibular apparatus
respond to angular acceleration on three planes
function of otolith organs in the vestibular apparatus
respond to linear acceleration
example of motor control in a child
learning new movements during development
example of motor control in adult
learning new movements as an adult (skill acquisition)
example of motor control with spinal injury/disease
injury that prevents normal/desired movement
is it necessary for a signal to be fully perceived for it to contribute to the control of movement?
no it’s not necessary
is perception always accurate?
no it can be creative or predictive
what kind of receptors are muscle spindles
length and velocity receptors
what kind of receptors are golgi tendon organs
tension receptors
