Week 1 L3 Measuring Motor Learning and Performance PDF

6/09/2024 MEASURING MOTOR LEARNING AND PERFORMANCE EXPT2151 MOTOR LEARNING AND MOTOR CONTROL...

6/09/2024 MEASURING MOTOR LEARNING AND PERFORMANCE EXPT2151 MOTOR LEARNING AND MOTOR CONTROL Dr Rachel Ward Senior Lecturer, Health Sciences, UNSW Medicine & Health 1 LEARNING OUTCOMES At the end of this lecture you should be able to: ▪ Describe and distinguish between the terms motor performance and motor learning ▪ Describe how motor learning is measured, and be familiar with the different types of performance variables and performance curves ▪ Understand the terms acquisition, retention and transfer, and how they relate to motor learning 02 2 1  6/09/2024 DEFINITION OF MOTOR LEARNING ▪ Motor skills are learned physical behaviors ▪ In order to study motor learning it is important to have a clear definition of the term ▪ Motor learning is: ▫ “a set of processes associated with practice or experience leading to relatively permanent changes in the capability for skilled performance” – Schmidt ▫ “a change in the capability of a person to perform a skill that must be inferred from a relatively permanent improvement in performance as a result of practice or experience” – Magill ▪ This changed capability is then a permanent part of the person’s makeup and is available at some future time when that skill is required 03 3 DEFINITION OF MOTOR PERFORMANCE ▪ Motor performance is observable behaviour ▪ Motor performance refers to the execution of a skill at a specific time and in a specific situation ▪ Performance may vary according to the specific conditions and situation under which a skill is executed, i.e. performance variables alter performance Learner Learning Environment Performance Environment Alertness Instructions Physical conditions (e.g. weather) Self-confidence Demonstrations Equipment Motivation Feedback Floor surface Fatigue Practice schedule Presence of a crowd or audience Anxiety Practice specificity Importance of the outcome 04 4 2  6/09/2024 COMPARING MOTOR PERFORMANCE AND LEARNING Motor Performance Motor Learning ▪ Observable behaviour – ▪ Inferred from performance – What we can see cannot be observed directly ▪ May represent only temporary ▪ Relatively permanent changes changes in behaviour in behaviour ▪ Influenced by ▪ Not influenced by performance variables performance variables Source: recreated from Edwards (2011) Motor Learning and Control: From Theory to Practice. Table 5.1, page 172 05 5 PERFORMANCE CHARACTERISTICS OF SKILL LEARNING We generally observe five (5) performance characteristics as skill learning takes place: 1. Improvement – performance is executed with a higher level of skill at some later time than at a previous time 2. Consistency – a person’s performance outcome and movement characteristics become more similar 3. Stability – the influence of perturbations (internal or external) on skill performance decreases as learning progresses. 4. Persistence – the improved performance capability lasts over increasing periods of time, i.e. the improvement in performance becomes permanent. 5. Adaptability – performance is adaptable to a variety of performance contexts, i.e. the performance of a skill becomes generalisable to different situations 06 6 3  6/09/2024 MEASURING MOTOR LEARNING ▪ Motor skill learning cannot be directly observed 2.6 but must be inferred from performance, i.e. by measuring levels of performance during 2.4 Mean movement time (s) practice of a skill 2.2 2 ▪ Performance can be illustrated graphically in 1.8 the form of a performance curve – a plot of the 1.6 level achieved on the performance measure for 1.4 each period of time 1.2 ▫ Performance measured on the vertical axis ▫ Time or number of trials on the horizontal 1 0 1 2 3 4 5 6 axis Acquisition trial blocks Source: recreated from Edwards (2011) Motor Learning and Control: From Theory to Practice. Table 5.2, page 177 07 7 THE SHAPE OF PERFORMANCE CURVES There are 4 basic patterns of performance curves ▪ Linear performance - Learning occurs ▪ Positively accelerating - A large amount of proportionally over time learning occurs later in practice Positively Inverse positively ← Performance Performance → Performance → accelerating ← Performance Linear Inverse linear accelerating Trials → Trials → Trials → Trials → ▪ S-shaped (Ogive) - Learning accelerates in middle ▪ Negatively accelerating - A large amount of phase of practice learning occurs early in practice S-shaped Inverse S-shaped Performance → ← Performance Negatively Inverse negatively ← Performance Performance → accelerating accelerating Trials → Trials → Trials → Trials → Source: recreated from Edwards (2011) Motor Learning and Control: From Theory to Practice. Table 5.4, page 182 08 8 4  6/09/2024 PERFORMANCE CURVE PLATEAUS & ASYMPTOTES ▪ The negatively accelerating performance curve is most commonly observed. This curve demonstrates the “Power Law of Practice”. ▪ The negatively accelerating curve indicates that it is not uncommon for a person to experience a period of time during which improvement seems to have stopped, i.e. a performance plateau ▪ It is important to realise that even through performance plateaus may occur, learning often still continues during these times ▪ An asymptote is an upper limit of performance that is considered the “best possible level of performance” ▫ as long as practice is continued, learning will continue to get closer to this upper limit Source: Edwards (2011) Motor Learning and Control: From Theory to Practice. Table 5.6, page 186 9 9 MERGING OF PERFORMANCE CURVES ▪ Performance curves may reveal only the initial phase of learning ▪ In later stages of learning different shaped curves may merge into negatively accelerating pattern, i.e. the Power Law of Practice (i.e. the performance asymptote) is eventually demonstrated Merging of Performance Curves Source: Edwards (2011) Motor Learning and Control: From Theory to Practice. Table 5.5, page 184 10 10 5  6/09/2024 ASSESSING MOTOR LEARNING – MEASURING ART ▪ There are three methods for 2.6 assessing motor learning from 2.4 Mean movement time motor performance observations 2.2 2 ▫ Acquisition (s) 1.8 ▫ Retention 1.6 ▫ Transfer 1.4 1.2 ▪ All three methods require 1 repeated observations 0 1 2 3 4 5 6 Retention Transfer Acquisition trial blocks test test (10 min. retention interval) Source: recreated from Edwards (2011) Motor Learning and Control: From Theory to Practice. Table 5.2, page 177 11 11 ACQUISITION Acquisition refers to the direct measurement of performance 2.6 ▪ All practice attempts are assessed 2.4 ▪ Measurements represent any changes in Mean movement time (s) 2.2 performance observed over the course of practice 2 ▪ A series of acquisition measures may be 1.8 graphed to illustrate changes in performance 1.6 over the course of practice – this is the performance curve 1.4 ▪ May illustrate important features of 1.2 performance 1 ▫ e.g. effect of various temporary performance 0 1 2 3 4 5 6 Retention Transfer variables (instruction methods, environment, Acquisition trial blocks test test motivation) (10 min. retention interval) Source: recreated from Edwards (2011) Motor Learning and Control: From Theory to Practice. Table 5.2, page 177 12 12 6  6/09/2024 RETENTION Retention tests refer to performance measurements conducted after acquisition trials 2.6 2.4 Mean movement time (s) ▪ Retention tests should be performed after 2.2 sufficient time, this allows any effects of 2 performance variables to have dissipated 1.8 ▪ Retention tests only measure the permanent 1.6 changes in performance, they are therefore a more accurate measure of learning than 1.4 acquisition tests 1.2 ▪ Retention tests demonstrate the learning 1 characteristic of persistence, i.e. the 0 1 2 3 4 5 6 Retention Transfer Acquisition trial blocks test test permanency of the changes (10 min. retention interval) Source: Edwards (2011) Motor Learning and Control: From Theory to Practice. Table 5.2, page 177 13 13 TRANSFER Transfer tests measure how effectively a 2.6 person can transfer the learning of a skill from one condition to another 2.4 Mean movement time (s) 2.2 ▪ A measure of the strength of learning in terms of how adaptable the learning is 2 to novel, non-practiced conditions 1.8 ▪ A measure of the adaptability or 1.6 generalisability of learning 1.4 1.2 1 0 1 2 3 4 5 6 Retention Transfer Acquisition trial blocks test test (10 min. retention interval) Source: Edwards (2011) Motor Learning and Control: From Theory to Practice. Table 5.2, page 177 14 14 7  6/09/2024 ASSESSING MOTOR LEARNING – MEASURING ART Each of the ART measures contribute something unique to our understanding of the learning process ▪ Acquisition ▫ Shape and rate of improvement ▫ Factors that influence performance ▫ Consistency and stability of performance ▪ Retention ▫ Learning independently of temporary performance variables ▫ Persistence or permanence of practice effects ▪ Transfer ▫ Influence of practice on strength of learning ▫ Adaptability to other conditions 15 15 TRANSFER OF LEARNING Functional exercise prescription is a form of transfer of skill learning from one context (i.e. practicing specific therapeutic exercises) to another context, (i.e. performing activities of daily living or workplace tasks) When prescribing functional exercises, Exercise Physiologists and Physiotherapists must have a clear understanding of the target skill and target context, and specifically match the prescribed therapeutic exercise to these goals ▪ Target skill – the real skill of interest during practice (e.g. specific workplace task) ▪ Target context – the real situation in which the skill will be performed (e.g. work environment where speed or accuracy of performing a skill may be important) 16 16 8  6/09/2024 POINTS FOR THE MOVEMENT INSTRUCTOR ▪ Good performance under certain conditions does not necessarily mean learning has occurred ▪ Improvement and consistency during practice sessions may be artificially influenced by characteristics of the practice session, e.g. feedback and guidance. Try not to always provide feedback, or physical guidance for every practice attempt ▪ As people learn motor skills, they not only show improvement in their performance, but also become more consistent in their performance. Increased consistency is a sign of learning ▪ Evaluation of retention and/or transfer gives a better indication of learning. Assess performance at the beginning of a practice session to assess how much has been retained (learnt) from the last session ▪ Performance plateaus are normal and common. Learning still does occur during these times so it is important to provide encouragement so the learner continues to practice 17 17 LECTURE SUMMARY ▪ Motor learning is distinct from motor performance ▪ Motor learning is inferred from measurement of motor performance ▪ Performance curves graphically display the improvement and consistency of learning during the acquisition phase. ▪ Retention tests demonstrate persistence and permanence in motor learning ▪ Transfer tests demonstrate adaptability and generalisability in motor learning ▪ Skills with shared common elements have greater transferability in motor learning, this is an important point for effective functional exercise prescription 18 18 9