Motor learning test #1

Specific patterns of motion among joints and body segments (can be voluntary & involuntary)

Movements

Tasks or activities that have specific goals to achieve (action goals) & Require voluntary control over movements of the joints and body segments

skills

Term often used synonymously with the term “motor skills”

actions

What are the characteristics of skill

• Goal is achieved with maximum certainty (know it will achieve your goal, it may not be perfect, but it doesn’t have to be).

• Goal can be achieved under a wide range of conditions (pressure, familiarity, etc).

• Goal is achieved with minimum cognitive effort (don’t really have to think about it).

The study of the processes involved in acquiring motor skills and of the variables that promote or inhibit such acquisition

motor learning

involves the study of the neural, behavioral, environmental, and synergistic mechanisms responsible for human movement and stability (How the nervous system controls the body).

motor control

_______ are expressions of the motor control systems

all motor skills

concerned with the neural processes that are associated with (or are causes of) movements

Neurophysiology

concerned with high-level skills with very little reference to the neurological mechanisms involved.

- How we cognitively organize skills, how did they fit together

Psychology

• Proposed that simple reflexes composed a human’s most complex movements

• Nobel Prize winner in 1932 for his work in the field of neurophysiology

• Discovered the synapses of neurons

Sir Charles Sherrington

• Russian Physiologist

• Developed a lot of theories regarding movement coordination

• Concerned with how we accomplish goals

• Developed the degrees of freedom problem

Nikolai A. Bernstein

• Interested in speed + accuracy

• Reaction time

• Movement accuracy

• Developed his own law

Paul M. Fitts

• Pioneer of kinesiology as an academic field of study at Penn State

• Advocated an experimental approach to the study of movement

Franklin M. Henry

• Infant Movement, how did they gain this

• Applied dynamical system theory to motor learning

Ester Thelen

Who studies motor learning?

athletic coaches/PE teachers, athletic trainers/PT/OT, movement scientists, ergonomics designer

• States there is no relationship between the variables you are studying

• An a priori statement of equality

• Represented by “H₀“

Null hypothesis

• Definite statement that there is a relationship between variables

• Statement on inequality

• Represented  by “H₁“ or “H_a“

Research hypothesis

a search through records of the past to determined what happened and why.

historical research

the research process that involves manipulating and controlling events or variables to solve a problem. 

experimental research

involves describing events or conditions, which the researcher does not actively manipulate.  

descriptive research

• The proposed cause

• A predictor variable

• A manipulated variable (in experiments)

Independent variable

• The proposed effect

• An outcome variable

• Measured not manipulated (in experiments)

Dependent variable

a necessary but not sufficient condition of a measure.

validity

the ability of the measure to produce the same results under the same conditions.

reliability

Many movements together accomplish same action

Ex: walking

Many-to-one relationship

One movement accomplishes many actions

Ex: wax on – wax off

One-to-many relationship

Two categories based on the size of the primary musculature required

Gross & Fine motor skills

Three main categories based on the specificity of where actions begin and end

Discrete, Continuous & Serial motor skills

involve a stationary supporting surface, object, and/or other people; performer determines when to begin the action

e.g. picking up a cup while seated at a table

Closed motor skills

involve supporting surface, object, and/or other people in motion environmental features determine when to begin the action

e.g. catching a thrown ball

Open motor skills

A classification system organized according to relationships among the component characteristics of what is being classified

Taxonomy

Two general characteristics of taxonomy

• The environment context in which the person performs the skill

• The function of the action characterizing the skill

features of environment to which movements must conform.

Regulatory conditions

variations in the regulatory conditions from one trial to the next.

Inter-trial variability

Features of the environment that do not necessarily affect the task (like color).

Non-regulatory conditions

maintaining base of support in one position; no change in the body location when performing the skill.

Body stability

changing the location of the base of support; requires change in location of the body during skill.

Can occur on object (car, bike, skateboard, escalator)

Requires active processing of change of position relative to the surround

Body transport

maintaining/changing position of moveable objects

Manipulation

complexity increases when a motor skill involves these

Open environment

Trial-to-trial variability

Object manipulation

Body transport

why would we use gentile’s taxonomy

• as a guide for evaluating motor performance capabilities, limitations, and deficiencies

• Systematic basis for selecting progressions of functionally appropriate activities to increase/overcome performance capabilities

• chart a persons progress

• Indicates the outcome or result of performing a motor skill (e.g. How far was a ball thrown?)

• Does not tell us about the movements that led to the outcome

• Does not provide information about the activity of various muscles involved

• Time to complete a task, reaction time.

Performance outcome measures

• Indicate the activity of specific aspects of the motor control system during the performance. (e.g. Which muscle was responsible for bringing the movement, how much joint angle (ROM) did he achieve?)

• Displacement, Velocity, Acceleration, ROM, EMG

Performance production measures

• Common measure indicating how long it takes a person to prepare and initiate a movement.

• The interval of time between the onset of a signal (stimulus) and the initiation of a response or a movement.

• does not include any movement related to a specific action, but only the time before movement begins.

• A stimulus or go signal is the indication to act

Reaction time

Components of reaction time (RT)

stimulus-identification, response-selection, response-programming

depends on characteristics of the stimulus and modality.

stimulus-identification

“knowing” what happened in the environment, the subject decides what response to make

response-selection

The time required to make a decision about a response is correlated with the number of alternatives.

Hick’s law

involves the set of muscular actions that will achieve the desired action.

response-programming

• Recording of muscle electrical activity (depolarization of t-tubes)

• Common use is to determine when a muscle begins and ends activation 

• fractionated RT (index of movement preparation)

• enables us to fractionate RT to obtain more specific information about movement preparation

Electromyography (EMG)

two fractionated RT components

pre-motor & motor time

Quiet interval between the onset of stimulus and beginning of activity

pre-motor time

Interval from the initial increase in muscle activity until the actual limb movement

motor time

can involve either spatial, temporal measures or both.

accuracy

refers to space dimensions, distance.

spatial

refers to time dimensions.

temporal

allow us to evaluate performance for skills that have spatial or temporal accuracy action goals

error measures

types of error measures

absolute, constant & variable error

• difference between the actual performance on each trial and the criterion for each trial

• measure of the magnitude of an error without regard to the direction of the deviation

• provides a general index of performance accuracy

absolute error

Algebraic value of difference between the actual performance on each trial and the criterion for each trial. It represents the amount and direction (+/-) of deviation.

• index of performance bias

constant error

The standard deviation of the CE scores. An error score representing the variability of the performance.

• Index of performance consistency (i.e. variability)

variable error

Describe Motion without regard to force that causes the motion.

• Performance production measures

kinematics

measures of kinematics

displacement, velocity & acceleration

Change in position of a limb or joint over time

displacement

Rate of change of displacement (i.e. speed) how long did it take you

velocity

Rate of change of velocity, how fast were you really going

acceleration

• The study of the role of force as a cause of motion

• Human movements organized by external and internal forces

• Importance of force: All three of Newton’s laws of motion refer to force

• Angular force = Torque

Kinetics

Displacement of muscle belly after stimulation

Whole muscle mechanomyography (wMMG)

level of oxygenation in the muscle (or brain)

Near infrared spectroscopy (NIRS)

Measures electrical activity in brain

Electroencephalography (EEG)

Neuroimaging technique that measures blood flow changes by detecting blood oxygenation levels

Functional Magnetic Resonance Imaging (fMRI)

Average neuron count

86 billion

how many neurons in the cerebral cortex

16 billion

initial segment (not axon hillock) initiates AP

integration of a neuron

release message molecules (hormones) into the blood.

neuroendocrine

membrane potential components

1. hydrophilic (attracted to water)

2. hydrophobic (afraid of water)

3. Protein channels allow ions to flow and be pumped out of cell

have a + charge (11 protons, 10 electrons)

Sodium (NA+) Ions

have a + charge (19 protons, 18 electrons)

Potassium (K+) Ions

create concentration gradients and electrical gradients across the cell membrane

NA+ and K+ Ions

How is the resting membrane potential maintained?

Leak channels & Na-K pumps

for all ions contribute to resting membrane potential (K+ most influential)

Leak channels

contribute to resting potential

Na-K pumps

travel over short distances and are activated by the opening of mechanically or chemically gated channels. (travels down cell bodies)

Graded potentials

travel over long distances and they are generated by the opening of voltage-gated channels. (travels down axons)

Action potentials

Gated ion channels in the membrane open to a variety of stimuli like…

• Mechanical force, eg. sensory neurons.

  • Chemical ligands, eg. neurotransmitters.

  • Voltage, eg. changes in the resting membrane potential.

excitatory postsynaptic potential (EPSP)

a graded potential depolarization

an inhibitory postsynaptic potentials (IPSP).  (doesn’t generate enough)

a graded potential hyperpolarization

move faster by jumping over myelin and depolarizing at the Nodes of Ranvier

action potentials

where neuron-to-neuron communication happens

synapse

causes an EPSP or IPSP that changes the excitability of the postsynaptic cell.

Postsynaptic current

4 structures most directly involved in the control of voluntary movement

Cerebrum

Diencephalon

Cerebellum

Brainstem

• One of two components of forebrain

• Covered by cerebral cortex

• Two halves - Right and Left

• connected by the corpus callosum

cerebrum

Gray tissue; 2- to 5-mm thick, undulating covering of ridges & grooves

cerebral cortex

called gyrus

ridges

called sulcus

grooves

the cutting of what may help reduce epilepsy in patients

corpus callosum

what are the four lobes of the cerebral cortex

frontal, parietal, occipital & temporal

control of voluntary movement

frontal lobe

control of somatosensory perception information

parietal lobe

control visual perception

occipital lobe