Midterm 1 Flashcards
Motor learning involves the study of
-acquiring new motor skills
-performance enhancement
-reacquisition of skills following inquiry, disease, and the like
Motor control involves the study of
How the neuromuscular system functions to activate and coordinate the mm and limbs involved in the performance of a motor skill
-while learning a new skill
-while performing a well learned skill
Motor dev involves study of
Motor behaviour and human development throughout lifespan
Three influences on how we perform a motor skill
- The person
- The skill
- Performance environment
What are skills
Tasks or activities that have specific goals to achieve
-require voluntary control over movements of joints and body segments
What are actions
Term used synonymously termed motor skills
Characteristics of skills and actions
- There’s a goal to achieve
- Types of motor skills of interest are performed voluntarily
- Motor skills require movement of joints and body segments to accomplish task goals
- Skills need to be learned or relearned
What are movements
Specific patterns of motion among joints and body segments
What are neuromotor processes
How nervous system controls movements and actions
Explain why we distinguish actions, movements, and neuromotor processes
-ppl initially learn to achieve action goals
-ppl use movements to discover the best movement to accomplish the action goal
-ppl modify neuromotor processes by refining movement and making it more efficient
- not everyone can accomplish action goal using same movement pattern
-diff measures are used to evaluate actions, movements, and neuromotor processes
Why do we classify motor skills
-provides basis for identifying similarities and differences among skills
- helps identify demands different skills place on performer
- provides basis for developing principles related to performing and learning motor skills
Gross motor skills
Require use of large musculature to achieve goal of the skill
Ex: walk, jump
Fine motor skills
Require control of small muscles to achieve goal of skill
Ex: skills involving hand eye coordination
Discrete motor skills
Specified beginning and end points, usually require simple movement
Ex: flipping a light switch
Continuous motor skills
Arbitrary movement beginning and end points; usually involve repetitive movements
Ex: steering car
Serial motor skills
Involve continuous series of discrete movements
Ex: shifting gears in stick shift
Environmental context
Physical location in which a skill is performed
- supporting surface
- objects involved
- other ppl or animals
Closed motor skills
Stationary supporting surface, object, or other ppl/animal; performer determines when to start the action
Ex: picking up cup while sitting at table
Open motor skills
Performed in an environment that supports surfaces, objects, or other ppl or animals are in motion; environmental context in motion determines when to start the action
Ex: catching a thrown ball
Regulatory conditions
Features of environmental context to which movements must conform to achieve action goal
- regulate spatial and temporal aspects of the movement as well as forces that underlie these characteristics
Non regulatory conditions
Features of environment that have no influence or only an indirect influence on movement characteristics
Intertrial variability
variations in regulatory conditions associated w performance of a skill change or stay from one trial to next
Ex: grocery store layout
Stationary regulatory conditions - no intertrial variability
-free throws
-walking in uncluttered hall
Stationary regulatory conditions - intertrial variability
- golf shots
- taking several sips of water from same glass
In motion regulatory conditions - no intertrial variability
- Hitting tennis balls projected at same speed from ball machine
- Walking on treadmill at constant speed
Body stability
Skills that involve no change in body location during performance of skill
Body transport
Active and passive changes of body locations
Object manipulation
Maintaining and changing position of moveable objects
Characteristics of Gentiles taxonomy
- each skill category poses different demands on performer
- skills that demand least of the performer are the simplest; those that demand the most are complex
- environmental context dimension and action function dimension form bases for creating 16 categories of motor skills
Practical application of taxonomy
Can be used for evaluating learners movement capabilities and limitations
-increase persons performance capabilities
-help person overcome their performance deficiencies
Why do we study the measurement of motor performance
For performance assessments
Two general categories of measurements
Performance outcome measures
Performance production measures
Performance outcome measures
Indicates outcome of motor skill
- doesn’t tell us about movements that led to outcome
- doesnt provide info about activity of various mm involved in each action or how the nervous system was involved
Performance production measures
Indicates how nervous, muscular, and skeletal systems function during performance of motor skill
What is reaction time
Measure indicating how long it takes a person to prepare and initiate movement
-stim indicates action
Events and time intervals of reaction time and movement time
Warning signal
-fore period
Go signal
-RT
Initiation of response
- movement time
Termination of response
RT is used to…
-assess how fast someone can initiate a required movement
-identify environmental context information someone uses to prepare to produce a required action
-assess capabilities of a person to anticipate required action and determine when to initiate it
3 types of RT sits
Simple RT
Choice RT
Discrimination RT
Premotor time
Quiet interval of time between onset of stimulus signal and beginning of mm activity
Motor time
Period of time from increase in mm activity until actual beginning of observable limb movement
Error measures
Allow us to evaluate performance for skills that have spatial or temporal accuracy action goals
3 error measures
Absolute error
Constant error
Variable error
Absolute error
Absolute diff between actual performance on each trial and the criterion for each trial
**see lec 2 for formula
-provides a general index of performance accuracy
Constant error
Signed plus or minus deviation from target or criterion
- serves as measure of performance bias
-lec 2 has formula
Variable error
Standard deviation of CE scores for series of repititions
Assessing error for two dimensions movement goals
Obtain qualitative assessment of bias and consistency by looking at actual grouping of locations
- when outcome of performing a skill requires accuracy in vertical and horizontal directions, the person assessing error must make modifications to the one dimension assessment method
Radial error
General accuracy measure for the two dimension situation
Root mean squared error
Commonly used error score for continuous skills
Kinematics
Description of motion without regard to force or mass; it includes displacement, velocity, and acceleration
Displacement
Change in spatial position of a limb or joint during movement
Velocity
Rate of change of an objects position w respect to time
V=displacement / time
Acceleration
Change in velocity during movement
A=change in velocity / change in time
Kinetics
Study of role of force as a cause of motion
-internal external forces
Electromyography - EMG
Recording of electrical activity of muscle or group of mm
- to determine when mm begin and end activation
Whole mm mechanomyography
Detects and measures lateral displacement of muscles belly following maximal percutaneous neuromuscular stimulation
Near infrared spectroscopy
Determines level of oxygenation in muscle
4 measures for brain activity
EEG
PET
FMRI
MEG
TMS
Electroenceohalography EEG
Measures electrical activity in brain
Positron emission topography PET
Neuroimaging technique measuring blood flow in brain
- PET scan detects activated brain regions
Functional magnetic resonance imaging fMRI
Neuroimaging technique that measures blood flow changes by detecting blood o2 levels while someone performs a skill or activity in MRi
Magnetoencephalography MEG
Assesses magnetic fields created by neuronal activity in brain
Transcranial magnetic stimulation TMS
Method in which a short burst of a field of magnetic waves is directed at a specific area of cortex
-noninvasive
Measuring coordination
Assess movement relationship between joints of limb and body segments
What is ability
General trait or capacity of a person
-enduring characteristics
-determinant of a persons achievement potential for performance of specific skills
What is motor ability
Ability that’s related to the performance of motor skill
- everyone has a variety of motor abilities
General motor ability hypothesis
Many motor abilities are highly related and can be grouped as a singular, global motor ability
Specificity of motor ability hypothesis
Many motor abilities are relatively independent in an individual
Static vs dynamic balance
Static and dynamic are two independent balance abilities
- as a motor ability, balance must be viewed as a multidimensional ability
External timing
Movement timing based on external source
Eternal timing example
Starting a sprint in track
Internal timing
Timing of movement based on someone’s internal representation of time
Internal timing example
Maintaining rhythm in dance without music
Fleishmans taxonomy of motor abilities
To define the fewest independent ability categories which might be most useful and meaningful in defining performance in the widest variety of tasks
Multi limb coordination
Ability to coordinate movements of a number of limbs simultaneously
Multi limb coordination example
Playing piano
Response orientation
Ability to make a rapid selection of controls to be moved
Response orientation example
Soccer play dribbling past a defender
Manual dexterity
Ability to make skillful arm-hand movements to manipulate large objects under speeded conditions
Manual dexterity example
Dribbling a basketball while running
What are aptitude tests used for
Predicting future performance of a motor skill or physical activity
What’s a neuron and what’s its size range
A nerve cell ranging from 4-100 microns
What are dendrites and their function
Extensions from cell body that range from none to thousands per neuron
-receive info from other neurons
What are the three types of neurons
Efferent (motor)
Afferent (sensory)
Interneuron
Afferent (sensory) neurons function
Send neural impulses to CNS from sensory receptors
-cell body and most of axon is in PNS; only the central process of the axon enters the CNS
Alpha motor neurons are found where & and what do they connect with
-found in spinal cord
-have long branching axons that connect directly w skeletal muscle fibers
Gamma motor neurons function
Supply a portion of skeletal muscle called intrafusal fibers
What are interneurons and what do they connect
Specialized neurons that originate and terminate in the brain or spinal cord
They connect:
-axons descending from brain and motor neurons
- axons from sensory nerves and the spinal nerves ascending to the brain
What four structures are most directly involved in the control of movement in the CNS
Cerebrum
Diencephalon
Cerebellum
Brainstem
What connect the L&r hemispheres of the cerebrum
Corpus callosum
Cortical neurons are either…
Pyramidal cells
Nonpyramidal cells
What is the motor control theory
Explains how nervous system produces coordinated movement to successfully perform motor skills in multiple envrionemnts
Essential issues important to motor control
- Meaning of coordination
- The degrees of freedom problem
Definition of coordination
Patterning of head, body, and limb movements relative to the patterning of environment objects and events
Two parts to consider regarding coordination
- Refers to relationship among head, body and limbs at a specific point in time during skill performance
- Need to consider movement coordination in relation to the context in which the skill is performed
Degrees of freedom (df)
Number of independent components in a ctrl system and the number of ways each component can vary
Degrees of freedom problem
Ctrl problem that occurs in the designing of a complex system that must produce a specific result
Open loop and closed loop control systems
Shows different ways the CNS and PNS initiate and control action
-generates and forwards movement instructions to effectors
Open loop system
Doesn’t use feedback
- instructions contain all the info needed for effectors to carry out planned movements
Closed loop system
Uses feedback
-ctrl centre issues info to effectors sufficient only to initiate movement
-relies on feedback to continue and terminate movement
Two theories of motor control
Motor program
Dynamical systems theory
Motor program
Memory based construct that controls coordinated movement
Dynamical systems theory
Emphasizes role of info in the environment and mechanical properties of body and limbs
Generalized motor program (gmp) characteristics
Proposed that each gmp controls a class of actions which are identified by common invariant characteristics
GMP invariant features
Form basis of what is stored in memory
-characteristics that don’t vary across performances of a skill within class of actions
GMP parameters
Movement related features of the performance of an action that can be varied from one performance to another
Example of an invariant feature
Relative time of the components of a skill
Example of a a parameter
Overall duration and the muscles used to perform a skill
Attractors
Stable behavioural steady states of systems
Characteristics of an attractor
- preferred behavioural states
- represent stable regions of operation around which behaviour typically occurs when a system is allowed to operate in its preferred manner
- energy efficient states
Order parameters
Functionally specific variables that define overall behaviour of the system
-aka collective variables
-enable a coordinated pattern of movement to be distinguished from other patterns
- relative phase is the most prominent order parameter: it shows how one joint moves relative to another
Control parameter
A variable when increased or decreased will influence the stability and character of the order parameter
Self organization
Behaviour that spontaneously emerges in response to a particular set of constraints
Examples of self organization
Bimanual finger movement task performed in the Kelso experiments
Coordinative structures (muscle synergies)
Groups of mm and joints constrained to act as functional units by the nervous system to act cooperatively to produce an action
-if perturbation stops one set of mm from working, another automatically compensates
Example of muscle synergies
Speaking with a mouth full of jelly beans
Perception action coupling
Inextricable linkage between info specifying body and environment and action ctrl
Perception action coupling- perception
Detection and utilization of critical information for the ctrl of action
Perception action coupling- action
Movement control features that are regulated and which enable the person to achieve the action goal
Perception action coupling- example
When walking, the time to contact an object in your pathway determines when you initiate stepping over the object
- your stepping action is coupled with your visual perception of the approaching object
Affordances example
Ratio of leg length to stair height determines whether a set of stairs is climbable
The optimal theory of motor learning
A new theory of motor control and learning that focuses on three issues:
1. Conditions that enhance expectancies for future performance
2. Variables that influence learners autonomy
3. External focus of attention on the intended movement effect
Mechanoreceptors
Are below skin surface in dermis
-provide CNS with temp, pain, and movement info
- greatest amount in finger tips
Meissners corpuscle
Rapidly adapting mechanoreceptor, touch and pressure
Merkel’s corpuscle
Slowly adapting mechanoreceptors, touch and pressure
Free neuron ending
Slowly adapting, including nociceptors, itch receptors, thermoceptors, and mechanoreceptora
Pacinian corpuscles
Rapidly adapting mechanoreceptor, vibration and deep pressure
Ruffini corpuscle
Slowly adapting, mechanoreceptor, skin stretch
Roles of tactile info in motor control
Accuracy
Consistency
Timing
Force adjustments
Proprioception
Sensation and perception of limb, trunk, and head position and movement characteristics
How does CNS receive proprioception information
Via Afferent sensory neural pathways that begin in specialized sensory neurons which are proprioceptors
Where are proprioceptors located
Mm, tendons, ligaments, and joints
Three primary types of proprioceptors
- Muscle spindles
- Golgi tendon organs
- Joint receptors
Intrafusal muscle fibers & where are they located
Specialized muscle fibers that contain a capsule w both sensory receptors and muscle fibers
-lie in parallel w extrafusal muscle fibers and are attached to muscle sheath
What do type Ia axons do
Wrap around middle region of intrafusal muscle fibers and detect changes in muscle length and velocity of length changes
GTO’s (golgi tendon organs)
-in skeletal mm near insertion of tendons into muscle
-type Ib sensory axons detect changes in mm tension or force
-poor detectors of muscle length changes
Joint receptors
-respond to changes in force and rotation applies to the joint
-respond to changes in joint movement angle esp at extreme limits of angular movement or joint positions
Surgical deafferentation
Afferent neural pathways associated w movements of interest have been surgically removed or altered
Deafferentation due to sensory neuropathy
Sometimes called sensory neuropathy
-large myelinated fibers of the limb are lost, leading to loss of all sensory information except pain and temp
Proprioception in motor control- movement accuracy
-specific kinematic feedback provided by proprioceptors to the CNS
- feedback about limb displacement provides basis for spatial position corrections
Proprioception in motor control- coordination of body and limb segments
-postural control
-spatial-temporal coupling between limbs and limb segments
3 roles of Proprioception in motor control
- Movement accuracy
- Timing of onset of motor commands
- Coordination of body and limb segments
The moving room experiment
Infants prioritized vision when touch/proprioception and vision provided conflicting info to CNS
Result of moving room experiment
Infants initiated unnecessary postural adjustments and often lost balance and fell
- adults show postural compensation in the moving room
Temporal occlusion techniques
-stop video recording or film at various times
-use of specially prepared visual occlusion spectacles
Event occlusion technique
Involves editing film or video recordings to occlude parts of the environmental context or the performer
Two visual systems for motor control
Central and peripheral
Binocular vision
Provides better info for movement control than monocular vision for motor skills such as locomotion in cluttered environments and reaching and grasping objects
-provides important info to help intercept moving objects
Central vision
Detects info only in the middle of 2-5 degrees of visual field
Central vision for reaching and grasping an object
Contributes to controlling transport of limb to the object and grasping the object
Central vision for walking on a pathway
Provides specific pathway information to stay on path and avoid obstacles
Peripheral vision
Detects info beyond central vision limits
-provides info about environmental context and moving limbs
Peripheral vision field
200° horizontally and 160° vertically
Optical flow
Moving pattern of light rays that strikes the retina from all parts of environment when head moved through space
Vision for perception (ventral stream)
-used for analysis of visual scene into form, colour, and features
-anatomically processes info from the visual cortex to the temporal lobe
-available to consciousness
Vision for action (dorsal stream)
-used for detecting spatial characteristics of a scene and guiding movement
-anatomically processes info from primary visual cortex to posterior parietal cortex
-not available to consciousness
Perception action coupling
When applied to visual system, enables precise coupling between body and environment
Sensory cortex
- loc
- function
Located posterior to central sulcus
-sensory info is transmitted via sensory nerves to the part of cortex that receives that type of info
Primary motor cortex
-loc
-structure
-function
-Frontal lobe just anterior to central sulcus
-contains motor neurons that send axons to specific skeletal muscles throughout body
-critical for movement initiation and coordination of moevemnts for fine motor skills
-control and learning of postural coordination
Premotor area loc & function
Ant to primary motor cortex
- controls organization of movements before they’re initiated and rhythmic coordination during movement
- enables transitions between movements of a serial motor skill
Supplementary motor area loc and function
-medial surface of frontal lobe
- helps control of sequential movements and prepares and organizes movement
Parietal lobe loc and function
Behind frontal lobe and central sulcus and above temporal
-interacts w premotor cortex, primary motor cortex, and small before and during movement.
Basal ganglia loc & parts
Buried in cerebral hemispheres
Consists of 4 nuclei
-caudate nucleus
-putamen
-substantia nigra
-globus pallidus
Function of basal ganglia
Receives neural info
- plays role in control of movement
1. Planning and initiation
2. Control of antagonist mm
3. Control of force
What is Parkinson’s
Disease associated w dysfunction of basal ganglia
- lack of dopamine production by substantia nigra
-motor control problems
Thalamus functions
Relay station- receives sensory info from spinal cord and brainstem; passes them through to cerebral cortex
-plays an important role in the control of attention mood and perception of pain
Hypothalamus function
Controls endo system and regulates homeostasis
Cerebellum loc and structure
Behind cerebral hemispheres and attached to brainstem
-cerebellar cortex covering which is divided into 2 hemispheres
Cerebellum functions
Controls movements and detects and corrects them
-controls hand eye coordination, movement timing, force ctrl, and postural ctrl
Pons function
Controls various body functions and balance
Medulla function
Regulatory centre for internal physiologic processes
Reticular formation function
Integrator of sensory and motor neural impulses
Two pairs of horns in spinal cord
Dorsal horns and ventral horns
Dorsal horns function
Cells transmit sensory information
Ventral horns
Contains alpha motor neuron cell bodies whose axons terminate on skeletal mm
Pyramidal tracts
60% from primary motor cortex
- control fine motor skill performance
Extrapyramidal tracts
Involved in postural control and control of hand and finger flexion and extension
Motor unit
End of the transmission of motor neural info
Fine movements
Have smallest number of mm fibers for each motor unit
Gross movements
Have the largest number of mm fibers per motor unit w as many as 700 muscle fibers innervated by one motor unit
Motor unit recruitment
Amount of force generated by muscle contraction depends on.number of muscle fibers activated
Neural control of voluntary movement
Performing a motor skill begins w a cognitively derived intent that’s based on the dictates of the situation or needs or the person
Trade off
Increasing speed yields decreasing accuracy and vice versa
Speed accuracy skills: fitts law
Showed we could mathematically predict movement time for speed - accuracy skills.
Application of fitts law to non laboratory skills
This law also applies to various non laboratory motor skill performance situations
Ex: darts, piano etc
Two motor control processes involved in performance of speed accuracy skills
Open loop ctrl
Closed loop ctrl
Open loop ctrl
Initial movements speed, direction and accuracy are under CNS control without feedback
Closed loop control
Visual feedback about limbs relative position to that target is used to guide the homing in phase of the limb to ensure it’s accurate landing on target
Preparation phase
Person uses vision to determines regulatory conditions that characterize environmental context in which action will occur
Initial flight phase
Vision acquires limb displacement and velocity info and acquires time to contact information that will be used later as the movement nears the target to make movement modifications
Termination phase
Begins just before and ends when the target is hit which is when the key is inserted into the keyhole
Prehension
Term for actions involving reaching for and grasping objects
Three components for prehension
Transport
Grasp
Object manipulation
Relationship between transport and grasp components
They are temporally coupled and they interact synergistically
Goodall and colleagues finding
Regardless of object size and distance, max grip aperture and hand closure occurred at approx two thirds of total movement time duration of action
Role of vision in prehension
Assists planning of prehension actions by providing info about regulatory conditions of the environmental context
Prehension and fitts law
Prehension demonstrates speed-accuracy take off characteristics as predicted by fitts law
What makes bimanual coordination hard
Inherent preference of the motor control system for controlling limb movements
-motor control system prefers symmetry
Catching a moving object - three phases
- Initial positioning of arm and hand
- Shaping of hand to catch the object
- Grasping object w fingers
Central pattern generator
Are in spinal cord and are involved in control of locomotion
Rhythmic structure of locomotion
Walking and running each have rhythmic structure and a rhythmic relationship exists between arms and legs
Benefit of analyzing rhythmic structure of gait patterns
Allows for assessment of coordination problems of trunk and legs
Spontaneous gait transitions
Important characteristic of locomotion
Ppl spontaneously change from walking to running gait at critical speed
Why do spontaneous gait transitions occur
Most popular: minimize metabolic energy use
No single cause for gait transitions has been determined
Avoiding contact w objects
Vision provides motor system with advance information about the body to determine how to avoid contact
Reaction time
An index of preparation required to produce an action
3 types of RT situations
Simple RT
Choice RT
Discrimination RT
What are the main steps on the RT diagram from signal to termination
- Warning signal (time)
- Go signal (RT start) (beginning of total response time)
- Response initiated (RT end and MT start)
- Response termination (MT end) (total response time end)
Hicks law
RT increases as the number of stimulus response choices increases
Cost benefit trade off
Cost and benefit that occur as a result of biasing the preparation of an action in favor of one of several possible actions
Stimulus response compatibility
Includes the spatial arrangement of stimuli and limb movements required to respond to them, and the physical characteristics or meaning of a stimulus and the type of response required
Stroop effect
Phenomenon that occurs when a person must verbally respond to the ink colour of s word that names a colour
Foreperiod length regularity
RT decreases when interval between warning and go signal is more regular
Movement complexity
RT increases as complexity of the action influences the time a person required to prepare the motor control system
Movement accuracy
RT increases as movement accuracy demands increase
Repetition of a movement
Repitition of the same response on the next attempt while performing a situation means that the persons RT for the next trial will be faster than it was for the previous attempt
Time between different responses to different signals
Delay of response to the second stimulus is called the psychological refractory period
-responding to the second stimulus is related to the response selection demands of the two S-R tasks that must be performed in rapid succession or to the timing of response initiation
Psychological refractory period
Takes time to realize what happened and react to it
Alertness of performer
Should be provided with a warning signal that indicates they must respond within the next few secs
Vigilance effects
RT increases the longer alertness is maintained
Attention focused on signal versus movement
Results showed that for both novices and experiences sprinters, RT was faster for the sensory set condition
Anticipatory postural adjustments
Organization of movements needed for postural support
Limb performance characteristics
Movement direction
Movement trajectory
Prepare in advance for ballistic movement and spatial accuracy
Object control characteristics
Force control
End state comfort control
Rhythmicity preparation
Pre performance rituals
-they prepare relative timing of upcoming movements
