KNES 385

Motor Control & LearningProf John Jeka

What is this class???Course Description: Physiological and cognitive bases for motor control and their applications to the acquisition of movement skills and understanding of movement disorders. Basic Question HOW are motor skills learned and controlled?? This includes: Execution of simple movements Expert performance Infant motor learning (i.e., learning to walk) Rehabilitation (i.e., stroke patient re-learning to walk)

Course OutlineUnit 1: Motor Learning Unit 2: Neurophysiology of Motor Control Unit 3: Theories of Motor Control Unit 4: Role of Memory / Attention

1

UNIT 1.1: Introduction to motor control, learning, skill and performance

Objectives1. Define / compare and contrast: motor learning, control, coordination, skill and ability Name and describe the factors that influence the above terms?

2. Classify motor skills based on established criteria 3. Identify characteristics of skillful behavior

Some Early DefinitionsAs an area of study. Motor control understanding how the neuromuscular system functions to activate and coordinate the muscles and limbs involved in the performance of a motor skill (Magill, 2007) Coordination the patterning of body and limb motions relative to each other and to the environmental objects and events Three aspects / dimensions of control???

Some Early DefinitionsAs an area of study.. Motor learning study of the processes involved in acquiring and refining motor skills that promote or inhibit that acquisition Sample Questions What is the role of feedback in motor learning? What type of feedback enhances learning? How do practice schedules impact motor learning? What is the role of memory in motor learning?Coker, 2004

2

You have to go faster.

Skills, Movements and Abilities

What is Skill?Write down a skill you think you possess

Do the answers vary?Consider the many activities we perform on an everyday basis. We perform actions that we have acquired over time. From walking down steps to playing video games, these are skills.

A skill is an action or task that has a specific goal to achieve (Magill, 2001).

3

Are all activities skills?An activity is a skill if it:

1) Is directed toward the attainment of a goal 2) Is performed voluntarily 3) Has been acquired by experience/ practice

What makes a skill a motor skill?A motor skill requires voluntary body/ limb movement (Magill, 2001).Is the skill you wrote down a motor skill under these criteria? Unless you thought of a cognitive skill, or one of the primary behaviors we are born with (i.e. suckling), it should be!

What about activities like

sitting

standing

walking

Levels of SkillfulnessAnother conceptualization of skill is something which distinguishes competence between, for example, experts and novices.

vs.

4

Levels of Skillfulness In addition to the criteria for a movement to be considered a skill, there are additional characteristics of skilled performance1. Adaptable 2. Consistent 3. Efficient

What are Movements?

Movements are behavioral characteristics of specific limb(s) that are components of a skill (Magill, 2001)i.e., movements are the building blocks of a skill

Why differentiate between skill, movement, etc?

There is a taxonomy or hierarchy(e.g., Biology: phylum class order family etc)

Characteristics that vary within and between people Movement Jump shot, dunk, lay-up Skill Put the ball in the basket Goal

Process measures

outcome measures

5

Classifying skills

Why classify skills? Simplifies discussion Allows comparison across research Provides context for coaches/therapists

Classifying skillsUnlike biological classifications, we use a continuum so that a skill does not have to exactly match a condition or fit into a box on some chart skills have high variation across many variables.Stuff Animal Vegetable Mineral

A one-dimensional continuum is a range between two ends on a given variable

Hot

Cold

Consider the 8 skills below

What characteristics do they have in common? Which characteristics differentiate them?

6

Classifying skillsCommonalitiesAll require concentration. All must focus attention on a specific point/thing. ???

DifferencesSome have a stable, predictable environment in which the skill is performed, some do not. Some use the whole body, some just use the hands/arms. Some are continuous, some are sporadic. Some involve fast movements, some slow. Some involve standing posture, some seated.

Basis for continua.

Classification 1: Size of musculature usedThe prime movers used in surgery and long jumping are clearly not the same.

GROSSUse large musculature; involve less movement precisionFundamental motor skills (jumping, locomotion, etc)

FINERequire control of small muscles; hand-eye coordinationWriting, typing, sewing, etc

Classification 2: Type of MovementDiscrete Serial Continuous

Have a clearly specified beginning and end (e.g., hitting a switch) one movement skills.

Involve a series of discrete movements (e.g., playing piano, hammering a nail)

Have arbitrary start and end (e.g., swimming)

??

Implications for analysis

7

Classification 3: Motor-cognitive dimensionLow cognitive demand Moderate cognitive demand High cognitive demand

Actions are automatic, with little thinking about task required

The motor component is less significant than the cognitive element

Classification 4: Stability of the environment Environment refers to the characteristics of objects/ people the skill is performed with Closed OpenEnvironment does not change while performing the skill. These tend to be self-paced; the object waits for your action. Environment is changing during performance of the skill. These are usually not self-paced, require constant adjustment.

Classifying skillsGross or Fine motor skill? Order the following skills in terms of the size of musculature used in the action. Punching a speed bag Typing your name Getting out of your car Open or Closed motor skill? Order the following skills in terms of the environment the skill is performed in. Snapping a football Basketball jump shot Bowling

8

So how does Skill relate to Ability?

AbilityAn ability is a stable trait or capacity of the individual that is a determinant of a persons potential for the performance of specific skills (Magill, 2001). Abilities are generally thought to be hereditary/ genetically determined, and by large unmodified by experience (Schmidt & Wrisberg, 2000).

The hardware people bring to a task.

INDIVIDUAL DIFFERENCES

Stable, enduring differences among people that contribute to differences in task performance (Schmidt & Wrisberg, 2000)

9

INDIVIDUAL DIFFERENCES

Body type

Abilities

Developmental Cultural background Emotional Stage make-up

INDIVIDUAL DIFFERENCES

Body type Cultural background Emotional make-up

Abilities Developmental Stage

Abilities vs. SkillsABILITIESStable Inherited traits Few in number Underlie performance of many skills

SKILLSModified by practice Developed Many in number Depend on different subsets of abilities(Schmidt & Wrisberg, 2000)

10

Generalized Motor Ability???

Abilities are highly related and can be characterized by a single, global ability(Brace, 1927; McCloy, 1934)

=

- Minimal empirical evidence

Specificity of Motor Ability???

Abilities are relatively independent. The allaround athlete has a high number of abilities(Henry, 1958)

Research evidence for specificity of motor abilities

Correlation

Rehabilitation

Identifying abilities allows the practitioner to get to the source of a problem. This can be achieved via a task analysis. May identify areas for compensation.

11

Skill or Ability?

Skill or Ability?

Skill or Ability?

12

Skill or Ability?Preparing for a career in professional sports is risky business because it requires focusing on getting a job that statistically, does not exist.

Hall of Shame???

Skill or Ability?

UNIT 1.1 : Introduction to motor control, learning, skill and performance

Objectives1. Define / compare and contrast: motor learning, control, coordination, skill and ability Name and describe the factors that influence the above terms?

2. Classify motor skills based on established criteria 3. Identify characteristics of skillful behavior

13

Measurement and Evaluation Of PerformanceUnit 1.2

Prof. John Jeka

Unit 1.1 Outline1.1 Introduction to Motor Control and Learning a) Motor coordination vs. motor control vs. motor learning b) Motor skills and abilities c) Classification of motor skills d) Characteristics of skillful performance 1.2 Assessment of Motor Skill Performance a) Outcome Measures (i.e., error scores, timing, etc.) b) Process Measures (i.e., kinematics, kinetics, brain imaging, etc.) 1.3 Motor Learning a) Characteristics of the learning process b) Assessment of motor learning c) Learning stages 1.4 Effects of practice on motor learning 1.5 Assisting the Learning Process a) Observational learning b) Augmented feedback

In order to: understand skilled performance. infer learning . compare individuals/groups We must measure performance

1

UNIT 1.2: Measurement and Evaluation of Performance

Objectives1. Compute, utilize, and interpret outcome and process measures used to assess motor control, coordination, and learning 2. Design a research experiment to examine specific research questions in motor control and learning.

What is Motor Performance???Motor performance is what we actually measure when a person performs a skill. It is divided into 2 types of measure:

Motor PerformancePerformance outcome measures (outcome scores) Performance production measures (process measures)

Outcome MeasuresIndicate the outcome of performing a skill, such as:How accurate was a shot/throw etc? How fast did a person move? How far did an object travel? ACCURACY TIME/SPEED MAGNITUDE

2

Measures of Accuracy: Error ScoresWhy measure error?Accuracy is a major component of human skill from everyday tasks to sports performance. The way in which we understand the accuracy of performance is simply to measure the extent to which performance differed from a criterion.

How do we measure error?The criterion can be a specific target in space, such as an archery target or a time, such as matching a rhythm.

Dimensionality of Error ScoresY axis Y axis

1 Dimension

2 Dimensions

Information Obtained from Error ScoresA dichotomy (hit/miss): This performance has 6 hits/4 misses (60%).

So does this!Is there a difference in the quality of performance?

Z

ax

X axis

X axis

X axis

3 Dimensions

is

3

Information Obtained from Error Scores10 8 6 4

28 points Only 40% hit

28 points 60% hit

Absolute Error (AE)The absolute difference in relevant units between the criterion and the performance outcome

abs (xi T)Absolute Error (AE) describes the error along a single dimension

We take multiple trials to gain a representative measure of performancethe average.Where:

AE = abs (xi T) n

= the sum of T = target n = number of trials

Absolute Error (AE)Trial 1 2 3 Xi 11 9 9.5 Abs Xi-T 11-10 9-10 9.5-10 = 1 1 0.5Target

2.5AE = 0.833 0 x2 x3 Then divide by n x1 the number of trials

AE =

abs (Xi T) n

9

10

11

4

Radial Error (RE) Absolute error for two dimensional tasks

RE =

Errorx2 + Errory2

What skill might this be appropriate for?

Radial Error (RE)Y axis

RE =

Errorx2 + Errory2c b

Pythagorean Theorema X axis

c2 = a2 + b2 c= RE = a2 + b2 Errorx2 + Errory2

Target

Radial Error (RE)Point Xaxis Yaxis Y axis

a b c d

3 -3 -1 2

3 1 -3 -2

a

b

X axis

d c

5

RE =Point

(x-axis error)2 + (y-axis error)2Xaxis Yaxis X2 Y2 X2+Y2

sqrt

a b c d

3 -3 -1 2

3 1 -3 -2

9 9 1 4

9 18 4.24 1 10 3.16 9 10 3.16 4 8 2.83 13.39 / n 3.35

Average RE

Bias in Performance Outcomes Absolute measures of accuracy may hold insufficient information. For example, they fail describe tendencies to over or under shoot. Constant error (CE): represents magnitude of error in a specific direction (i.e., it is no longer absolute). CE = (xi T)Target Error

0 Vs.

10 ft

AE = abs (xi T) you missed by that much CE = (xi T) you overshot by that much

Constant Error (CE)Trial 1 2 3 Xi 11 9 9.5 Xi-T 11-10 9-10 9.5-10 = 1 -1 -0.5

Then divide by n the number of trials

-0.5Target x CE = -0.167 02

x3

x1

9

10

11

CE =

(Xi T) n

6

Variability in Performance Outcomes Variability is a measure of consistency in performance. The typical measure is the standard deviation (Std Dev). Where: (x-m)2 Std Dev = n-1 = the sum of x = the individual score m = the mean n = the sample size

Variable error (VE) is an index of how much variability there is in the accuracy of performance.

Variable Error (Std Dev) (x-m)2 n-1

Std Dev =

Trial 14 2 3 1 5

Trial 2 Trial 3 Trial 4 Trial 5

1.5 0.25 0.25 3 0.5

Variable Error (Std Dev)Std Dev = Trials 1 2 3 4 5 Sum Mean Error 1.5 0.25 0.25 3 0.5 5.5 1.15.5

(x-m)2 n-1 (x m) -0.85 -0.85 1.9 -0.6 (x m)2 0.16 0.7225 0.7225 3.61 0.365.5775

7

Variable Error (Std Dev)Std Dev = Trials 1 2 3 4 5 Sum Mean Error 1.5 0.25 0.25 3 0.5 5.5 1.15.5

(x-m)2 n-1 (x m) 0.4 -0.85 -0.85 1.9 -0.6 (x m)2 0.16 0.7225 0.7225 3.61 0.365.5775

Variable Error (Std Dev)Std Dev = Trials 1 2 3 4 5 Sum Mean Std Dev Error 1.5 0.25 0.25 3 0.5 5.5 1.1 1.1815.5

(x-m)2 n-1 (x m) 0.4 -0.85 -0.85 1.9 -0.6 (x m)2 0.16 0.7225 0.7225 3.61 0.365.5775

Skilled Performance??

(A) (B) Which would be regarded as most skilled? (A) has a lower AE & lower CE, but a higher VE than (B). (B) has a higher AE & higher CE, but a lower VE than (A)

8

Continuous SkillsRoot mean square error (RMSE) Error between a participants displacement (position) curve and a criterion (ideal) curve Computes one error score for the total duration of the task

Performance Outcome MeasuresMagnitude Accuracy Time/speed

Dichotomy hit/miss Zones of accuracy Absolute error (AE) Radial Error (RE) Constant error (CE) Variable error (VE) RMSE

Speed: Reaction and Movement Time

Reaction time (RT): interval between the onset of a signal or stimulus, to the initiation of a response

Stimulus or Go signal

Light/Color Word/Sound Shock/Vibration

Vision Hearing Touch

9

Reaction TimeSimple RTStimulus Used in information processing studies

Choice RT

Discrimination RT

Response key Index Index Middle Ring Index

Reaction TimeMatch the following

Simple RT Choice RT Discrimination RT

What are typical RT values?Simple RT: Light Siren Electrical shock All together Choice RT:# of choices ~RT (ms) 1 200 2 350 3 400 4 450 5 500 6 550 7 600 8 600 9 650 10 650

240 ms 220 ms 210 ms 180 msSwink (1966)

Damon et al. (1966)

10

Performance Measures: Time Reaction time (RT): the interval of time from the onset of a go signal or stimulus to the initiation of a response Movement time (MT): the interval from the initiation of the response to the completion of the movement. Response time: the sum of RT + MT. From the onset of a go stimulus to the completion of the movement.These are all defined by observable events

Electromyography (EMG) in RT measures EMG, which indicates electrical activity of muscle, has been used to separate RT into central and peripheral components.

Research shows that following presentation of a stimulus, for a portion of RT, there is no electrical activity. This 40-80 ms period is known as pre-motor RT represents CENTRAL PROCESSES (decision making/ perceptual processes etc).Weiss, 1965

Electromyography (EMG) in RT measuresWarning Stimulus Presentation Movement Onset Movement Offset

EMGPre-motor Foreperiod Motor

RT

MT

Response time

11

Measures of MagnitudeIndicate the size of an outcome, and have particular relevance in sports settings.

Distance

Weight

How far you throw

HeightHow much you lift

How high you jump

Performance Outcome MeasuresMagnitude Accuracy Time/speed

Distance Height Weight

Dichotomy hit/miss Zones of accuracy Absolute error Constant error Variable error RMSE

Reaction Time Movement Time Response Time

Performance Process Measures Outcome measures do not tell us how a result was achieved. To understand what underlies performance, we need process measures

Kinematics Kinetics EMG

Brain activity/ imaging

12

Kinematics Measures which describe motion, without regard to the cause of that motion. Muybridge (1878) in California, was the first to capture serial images of fast animal motion.

Kinematics Modern systems such as Optotrak use infra-red technology to relay the spatio-temporal positions of markers. 3-D Data can be captured at 1000 Hz.

Kinematics

Video/filmSlow sampling rate Wide workspace of data collection Variation in precision of measurement Forgiving (extrapolation) Inexpensive

OptoelectricFast sampling rate Narrower workspace (less as Hz increases) Very precise Less forgiving ExpensiveSchmidt & Lee (1999)

13

KinematicsY axis

Both methods provide raw data in the form of x, y, and z coordinates. From this we can calculate the following: Displacement (linear/angular) Velocity (linear/angular) Acceleration (linear/angular) Coordination (relative motion)

Motion Analysis

Motion Analysis

Z

ax

X axis

3 Dimensions

is

14

Displacement Change in spatial positionTime (s) 0 4.1 7.9 11.9 15.7 19.8 24.1 28.1 32.1 35.8 40.0 Disp (m) 0 40 60 80 100 120 140 160 180 2000 0 5 10 15 20 25 30 35 40 45

Velocity (m/s)

Accel (m/ s^2)250

Displacement

Displacement (m)

20

200 150 100 50

Time (s)

Velocity the rate of change in position (displacement)Time (s) 0 4.1 7.9 11.9 15.7 19.8 24.1 28.1 32.1 35.8 40.0 Disp (m) 0 20 40 60 80 100 120 140 160 180 200 Velocity (m/s) Accel (m/ s^2)

v=

displacement time 20 0 m 4.1 0s

v=

v = 4.88 m/s

Velocity the rate of change in position (displacement)Time (s) 0 4.1 7.9 11.9 15.7 19.8 24.1 28.1 32.1 35.8 40.0 Disp (m) 0 20 40 60 80 100 120 140 160 180 200 Velocity (m/s) 4.88 5.29Velocity (m/s)

Accel (m/ s^2)

7 6 5 4 3 2 1 0 0

v=

displacementVelocity

time 20 0 m 4.1 0s

5.02 5.22 4.91 4.61 5.06 4.88 5.43 4.76 N/A

v=

v = 4.88 m/s

5

10

15

20

25

30

35

40

Time (s)

15

Acceleration the rate of change in velocityTime (s) 0 4.1 7.9 11.9 15.7 19.8 24.1 28.1 32.1 35.8 40.0 Disp (m) 0 20 40 60 80 100 120 140 160 180 200 Velocity (m/s) 4.88 5.29 5.02 5.22 4.91 4.61 5.06 4.88 5.43 4.76 N/A Accel (m/ s^2)

a=

velocity time 5.29 - 4.88 m/s 4.1 0s

a=

a = 0.1 m/s^2

Acceleration the rate of change in velocityTime (s) 0 4.1 7.9 11.9 15.7 19.8 24.1 28.1 32.1 35.8 40.0 Disp (m) 0 20 40 60 80 100 120 140 160 180 200 Velocity (m/s) 4.88 5.29 5.02 5.22 4.91 4.61 5.06 4.88 5.43 4.76 N/A Accel (m/ s^2) 0.10Acceleration (m/s^2)0.5 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 -0.4 -0.5 Time (s)0

a=

velocity Acceleration time 5.29 - 4.88 m/s 4.1 0s20 25 30 35

-0.07 0.05 -0.08 -0.07 0.10 -0.05 0.13 -0.18 N/A N/A

a=

5 a = 0.1 10 15 m/s^2

Coordination Relative motion is the motion of one segment or point in a configuration relative to another Postural coordination patterns

Upright Stance

Ankle Pattern

Hip Pattern

16

Intra-limb Coordination: Running

ITO = ipsilateral take-off IFS = ipsilateral foot-strike CTO = contralateral take-off CFS = contralateral foot strikeEnoka et al. (1978)

Kinetics Measurements of the forces which cause motion. Predominantly apply Newtons laws of motion.

Examples: Force: push or pull on an object; product of an objects mass and acceleration (e.g., ground reaction force) Torque: angular force directed around an axis of rotation; product of force and perpendicular distance to the axis Momentum: product of an objects mass and velocity

Equipment includes force platforms, strain gauges, etc.

Kinetics: Force Platform

17

Electromyography (EMG) Measures the electrical activity in muscle. Electrodes are attached to the skin superficial to the muscle belly

Electrodes detect electrical activity which result in muscular contraction. Electrical signals are amplified and recorded. Data describes temporal patterning, and amplitude.

STUDYING THE LIVING BRAIN

Brain activity and Imaging

Electroencephalography (EEG) Electrodes placed on skull detect and record brainwaves, or the electrical patterns created by the rhythmic oscillations of neurons. Technique often uses: Event related potentials (ERPs): electrical peaks that are related to a specific stimulus. Coherence- functional communication between brain areas of interest

18

Electroencephalography (EEG) Electrodes placed on skull detect and record brainwaves, or the electrical patterns created by the rhythmic oscillations of neurons.

Electroencephalography (EEG)

Pros:Directly measure brain activation Good temporal Resolution Relatively cheap Easy to transport Silent! Easy to use for MANY behavioral paradigm and with different populations

Cons:Spatial resolution Set-up time

Positron Emission Tomography (PET) Uses computed tomography (CT) and radioactive markers injected in the bloodstream. Identifies areas of brain working most based on fuel intake (i.e., glucose and O2 providing energy to firing neurons).

Characteristics: Good spatial resolution; poor temporal resolution

19

Magnetoencephalography (MEG) Records the magnetic fields produced by the electrical activity of the brain.

Characteristics: Better spatial resolution; good temporal resolution

Magnetoencephalography (MEG)

Pros:Magnetic fields are less distorted Excellent temporal resolution Reference-Free Less set-up time Direct measure of brain activation

Cons:Orientation of MEG Less readily available

Functional Magnetic Resonance Imaging (fMRI) Aligns atomic particles in tissues by magnetism, then bombards them with radiowaves. Different tissues return different radio signals. fMRI determines areas in brain where there is most oxygenated hemoglobin.

Characteristics: Good spatial resolution; poor temporal resolution

20

Functional Magnetic Resonance Imaging (fMRI)

Pros:Excellent spatial resolution

Cons:Indirect measure of brain activity Susceptible to movement artifacts Use of templates and atlases

Brain ImagingLow Resolution High Resolution

Spatial Resolution

Temporal Resolution

Low Resolution

Human Connectome

21

Summary of Performance MeasuresOutcomeAccuracy Error scores - Absoluter error (1-D)- Radial error (2-D) - Constant error - Variable error

ProcessDescription of movement Kinematics - displacement- velocity - acceleration - relative motion - phase plane portraits

Movement Speed Reaction time - simple- choice - discrimination

Forces underlying movement Kinetics - force- torque - moment

Movement time Response time Magnitude

Electrical activity of muscle EMG Brain activity/images EEG, PET, fMRI & MEG

But before you start measuring performance..Is it an objective measure? A measure is objective if it can be employed consistently by different people. It is also objective if the measurement scale is appropriate. Is it a valid measure? This refers to whether a test measures what it is supposed to measure. Does your measure have construct validity? Magnitude measures almost always do. However, is accuracy, consistency, bias a construct of your skill? Is it a reliable measure? Is the measurement repeatable? Deviations in the way a test is performed can result in markedly different results. As a result, change may be incorrectly attributed to difference in performance.

Improving your tests objectivity, reliability, and validity

Consider the purpose of the skill Keep the test environment consistent Document your methodology Standardize measures Dont test yourself!

22

Scientific MethodStep 1

Develop a testable research questionStep 2

Formulate hypotheses what is the anticipated outcome and why?

Scientific MethodStep 3

Operationally define independent and dependent variables Independent : the manipulated variables/ factors Dependent: the measured variable (presumably influenced by the independent variable(s))

Scientific MethodStep 4

Design study to test research question 1 2M F

3

4

Subjects.? Who How many? Independent groups or repeated measures? # of trials? How will you control for extraneous variables?

23

Scientific MethodStep 5 Observe behavior and gather dataMale SUB 1 SUB 2 SUB 3 SUB 4 SUB 5 SUB 6 SUB 7 SUB 8 SUB 9 SUB 10 SUB 11 12 16 21 22 16 16 14 25 22 34 12 Female 11 14 12 17 12 16 11 21 17 26 11

Scientific MethodStep 6Male Female 11 14 12 17 12 16 11 21 17 26 11 15.27273 4.818525

Analyze and interpret results of study Run descriptive statistics (and inferential statistics)

SUB 1 SUB 2 SUB 3 SUB 4 SUB 5 SUB 6 SUB 7 SUB 8 SUB 9 SUB 10 SUB 11 MEAN SD

12 16 21 22 16 16 14 25 22 34 12 19.09091 6.579583

UNIT 1.2: Measurement and Evaluation of Performance

Objectives1. Compute, utilize, and interpret outcome and process measures used to assess motor control, coordination, and learning 2. Design a research experiment to examine specific research questions in motor control and learning.

24

7/4/12

Introduction to Motor LearningUnit 1.3

Prof. John Jeka

Unit 1 Outline1.1 Introduction to Motor Control and Learning 1.2 Assessment of Motor Skill Performance 1.3 Motor Learning Characteristics of the learning process Assessment of motor learning Learning stages 1.4 Effects of practice on motor learning 1.5 Assisting the Learning Process

UNIT 1.3: Introduction to Motor Learning

Objectives1. Define and distinguish between motor performance and learning 2. Identify key characteristics of the learning process 3. Describe and compare / contrast different methods to assess motor learning 4. Design research experiments to assess motor learning 5. Describe and compare / contrast different stages of motor learning

1

7/4/12

Introduction to Motor Learning!Although we are born with the neural structures which facilitate the acquisition of knowledge and skill, with the exception of elementary reflexes, infants are born without repertoires of behaviour Bandura (1977) !

Complex human behaviours acquired over time and development are the result of experience and observation. In essence, they are learned. "

Understanding Learning

Learning is a relatively permanent change in the capability to perform a skill Learning cannot be directly measured it is inferred from performance! Influenced by performance variables Temporary Not necessarily a result of practice

Observable behavior

Learning

refers to a change in the potential or capability to perform a behaviour .why?

2

7/4/12

Characteristics of the learning process

1. Performance of

skills shows an improvement over a period of time

Characteristics of the learning process2. Performance becomes more consistent (less variable) over time1.4 1.2

Variability

1 0.8 0.6 0.4 0.2 0 0 5 10 15 20 25 30 35 40

Blocks of Trials

Characteristics of the learning process3. There is greater persistence in the improvements made

Time delay" Practice" Repeat"Krakauer et al., 2005: Visuomotor adaptation

3

7/4/12

Characteristics of the learning process4. Performance of the skill becomes more adaptable !

Performance Curvesare a method of assessing learning by recording levels of performance across practicePerformance measure"

Dependent variable for learning

time (or time period)"

e.g., absolute error, variable error, time-on-task, RT

Learning a new skill is typically characterized by one of four performance curves

Performance Curves(ceiling effect)

Linear

Negatively accelerated

Positively accelerated

(ceiling effect)

S-shaped

4

7/4/12

Performance Curves in KinematicsMore complicated as they show not only changes in performance between trials, but within trials "Improvement in performance can be assessed by how close the movement pattern matches the criterion. Consistency can be assessed by the extent to which the movement patterns vary.

Assessment of LearningIt is not wise to infer learning from practice because:Practice data provides no evidence for permanent/ semi-permanent changes in behavior Performance during practice is susceptible to over-estimating and under-estimating learning

Performance in practice may temporarily plateau230 220 210 200 190 180 170 160 150 1 2 3 4 5 6 7 8 9

Absolute error

Days of practice

Assessing Learning by Retention

The typical design is as follows: Pre-test Practice/acquisition

+ 1 to 7 days Post-test Retention test

Measures ability to perform task before the treatment

Measures ability to perform task after period of practice

Measures ability to perform task after a nopractice retention interval

5

7/4/12

Assessing Learning by RetentionPre-test Practice/acquisition Post-test Retention test

Effect of practice on performance Learning Experimenters may test several groups using the same designPre Control Verbal Guidance Video Model 3 x 3 design Post

Decay of performanceRetention

Assessing Learning by Transfer

Transfer of learning describes how previous practice on a task influences the learning of a new skill

Transfer can be negative, where previous practice of one skill hinders learning of a new skill or positive, where previous practice in one skill assists learning of a new skill

Positive Transfer

Sensorimotor adaptation experiment (Abeele & Bock, 2003) Group A (left) performed tracking task in rotated environment before the pointing task (vice versa for Group B) Group A smaller errors on pointing task compared to Group B (right) Positive transfer across the tasks!!!!

6

7/4/12

Negative Transfer

Sensorimotor adaptation experiment (Caithness et al., 2004) Task A = 30 CCW rotation; Task B = 30 CW rotation Angular error on day 2 (task B) exceeded -30 degrees, suggesting that performance on Task A hindered performance on Task B Negative transfer!!

The significance of transfer1. It can define the appropriate sequencing of skills to be learned Curricula tend to be organized in a simple-to-complex order Early fundamentals need to be in place before moving on Skill classifications can be a useful tool to guide transfer PTs need an appropriate order of functional treatment

The significance of transfer2. It can assess the effectiveness of practice conditions!Practice condition 1"

Practice condition 2" Criterion performance"

Practice condition 3"

7

7/4/12

Theoretical explanations for positive transfer of learning

Identical elements theory (Thorndike, 1914)

Task 1 Task 2

Task 3 Task 4

Little overlap of elements = little transfer

Greater overlap of elements = greater transfer

Transfer-appropriate processing theory

Suggests that movement components need not be similar. Instead, positive transfer is more likely between two skills or practice conditions which share cognitive processing characteristics

(Morris et al, 1977)

Research designs to assess positive transferGroup Experimental Control Practice conditions Practice skill A No practice Transfer test Perform skill B Perform skill B

OR"Experimental Control Skill in context 1 No practice Skill in context 2 Skill in context 2 x 100 Experimental group + control group

Experimental group control group Percentage of transfer =

8

7/4/12

Contextual variations in transfer testsChanges to the physical environment Changes in availability of feedback information Changes to learners personal characteristics

Novel skill variations in transfer testsChanges to the task itself (e.g., faster/slower)

i.e.,

Changes in constraints!

Transfer

Mobility Simulator The devices can apply 6DOF forces and torques to the feet Simulate varied support surface conditions. The platforms are integrated with two VE simulations, a street crossing and park path.

http://shrp.umdnj.edu/rivers/facilities/index.htm

9

7/4/12

Nintendo Wii Use of Wii in physical rehab settings (children with cerebral palsy)Deutsch et al., 2008

Stages of LearningFitts & Posner (1967) 3-stage modelPractice time continuum

Cognitive stage Learner encounters cognitive problems, and must integrate information. What should I do? How should I move? Large errors; variability

Associative stage Learner makes associations b/w environmental cues and movements. Learner detects errors. Performance is refined, variability and error decreases.

Autonomous stage Learner performs skill in habitual or automatic manner. No conscious thought of action processes. Learner can divide attention.

Gentiles two-stage model (1972, 2000)Stage 1: Getting the idea of the movement The learner organizes a movement pattern by delimiting the potential muscular responses in tune with the demands of the environment. Must discriminate Regulatory conditionsEnvironmental features which specify how movement must be performed

Non-regulatory conditionsEnvironmental conditions which do not influence movement characteristics.

10

7/4/12

Gentiles two-stage model (1972, 2000)Stage 1 also is highly cognitive problem solvingLearner leaves stage 1 with a framework for the organization of the movement, but performance is variable and inefficient

Stage 2: Fixation/diversification Learner must acquire adaptability for the skill consistency economy of effort

Gentiles two-stage model (1972, 2000)Closed Open

Skills require fixation Learner must refine pattern for consistency.

Skills require diversification Learner must diversify the basic movement pattern. Must be highly tuned to the regulatory conditions

Embedded Hierarchyof coordination, control and skill (Newell, 1985) coordination controlToward skill

Early skill learning emphasis within the synergy of coordination and control is upon assembling a new movement pattern (coordination) Later in skill learning, when the movement pattern is assembled, the emphasis is upon scaling the movement pattern (control)

11

7/4/12

Bernsteins Degrees of FreedomThe degrees of freedom (DOF) in any system is the number of independent elements to be controlled DOF problem: how can a complex system act to constrain so many degrees of freedom into a functional unit? e.g., The human arm has 7 degrees of freedom" 3 at the shoulder" 1 at the elbow" 1 at radioulnar joint" 2 at the wrist"

Bernsteins Degrees of FreedomEarly learning novice simplifies movement by freezing a portion of available DOF.

Later learning there is a release of the DOF. Dynamics of action become more apparent to the learner

Expert - release and organization of DOF. Flexibility to freeze or release DOF at appropriate moments

UNIT 1.3: Introduction to Motor Learning

Objectives1. Define and distinguish between motor performance and learning 2. Identify key characteristics of the learning process 3. Describe and compare / contrast different methods to assess motor learning 4. Design research experiments to assess motor learning 5. Describe and compare / contrast different stages of motor learning

12

7/4/12

Role of Memory in Motor Control and LearningUnit 4.1

Prof. John Jeka

UNIT 4.1: Role of Memory in Motor Control and Learning

Objectives 1. Define / compare and contrast: verbal and motor memory, declarative and procedural memory, short- and long-term memory 2. Describe methods used to assess memory 3. Explain the neurophysiological processes underlying memory 4. Describe different causes of forgetting

Information processing does not simply refer to generating short-term responses. Information must be retained, and accessed later.

?? In what form are memories stored?

1

7/4/12

MemoryHow is that I can remember the names of every teacher I had in school (Mrs. Bungay, Mrs. Abel, Mr. Jones, Miss Waugh, Miss. Wilson, Mr. Jones II, Mrs. Winterbottom, Mr. Robottom, Mr. Cormack, Mr. Dean, Mrs. Court etc , etc) But I forget a name within 5 minutes of meeting someone new?

MemoryWhy does repetition and association make it easier to remember something? Why are phone numbers 7 digits?

Is memory for action the same as memory for numbers, language etc?

MemorySome definitions. - The internal record or representation of some prior event or experience - Retention of experience-dependent changes over time - The capacity to remember - Tulving (1985): the capacity that permits the organism to benefit from past experiences

2

7/4/12

Motor MemorySchmidt & Lee (1999)

the persistence of the acquired capability for motor performance

Motor Memorytheories of motor control & learningMotor program: a memory structure, or representation that stores information necessary for action.

Schema theory (Schmidt, 1975,88): we have a motor response schema which provides rules governing an action.

Motor Memoryas a reference of correctness in closed-loop motor control theory:System goal

Detection, recognition, matching Decisions Muscle response

inputReference mechanism

errorExecutive level

instructionsEffector level

outputEnvironment

3

7/4/12

Human Memory System

Carter, 2000

Amygdala: traumatic, uncon. mems Temporal lobe: LT memories

Caudate nucleus: instincts (genetically -coded memories) Putamen: procedural memories Hippocampus: laying down/retrieving (spatial) memories

Neurophysiological Basis of Memory Memories are groups of neurons which fire together in the same pattern each time they become activated(Carter, 2000).A. 2 Linked connection strong enough to trigger firing Weak connection 1 3

Initial stimulus

Neurophysiological Basis of Memory Memories are groups of neurons which fire together in the same pattern each time they become activated(Carter, 2000).B. 2 Linked connection strong enough to trigger firing Weak connection 1 3

Initial stimulus

4

7/4/12

Neurophysiological Basis of Memory Memories are groups of neurons which fire together in the same pattern each time they become activated(Carter, 2000).C. 2 Linked connection strong enough to trigger firing Weak connection 1 3The faster the neural activity, the more likely the charge will pass to neighboring cells

Initial stimulus

Neurophysiological Basis of MemoryEvery perceived sensation creates new neural connections But, if not laid down in memory the impression rapidly fades

Lingering patterns connect with and create activity in other neural networks = an association

In principle, if same neural network is lit up should give rise to same thought etc. In reality similar, mutated patterns occur

As memory fades, neural connections are lost. (Carter, 2000)

Verbal vs. Motor MemoryMagill (2001): verbal and motor memory considered as part of same memory system. But two conditions suggest they are not: Apraxia person cannot produce movement from verbal command Agnosia person can produce a movement but cannot name it Also, depend on different neural structures Verbal: consolidation into LTM depends on medial temporal lobe

5

7/4/12

Key DefinitionsRetention: the information that we remember Forgetting: the information we cannot remember Is memory not there?Cannot retrieve it?

Retrieval: the process of calling up information from LT memory (ST memory?) Serial search, activation

Measuring MemoryRecognition tests ability to recognize something from list/group of stimuli.

Recall tests ability to reproduce something from memory.

How do these relate to our examinations in this class???

Put down your pens

6

7/4/12

83

Tick..tock

Recall: How many items do you remember from the previous slide?

7

7/4/12

Recognition: Which of the following items were on the test slide?

Recall vs. RecognitionList the 3 proposed stages of information processing Stimulus identification ____________________________________ Response selection ____________________________________ Response programming ____________________________________

With the condition apraxia, a person:

A. Cant remember the names of movements they do B. Cant produce movement from a verbal command C. Cant hear verbal commands D. Cant remember anything

Two-component Theory of Memory

Short-term Memory

Long-term Memory Declarative Procedural

explicitEpisodic

implicit

Semantic

8

7/4/12

Short-term Memory- capacity to retain info for short time(Peterson & Peterson, 1959: