Motor Learning and Control

1. Motor Learning and Control • Defining learning and control • Measurement Schemes • Open vs. Closed loop control • Stages of Learning • The role of practice • Amount • Composition • Scheduling

2. Motor Control Understanding the execution of the events (physiological or behavorial/psychological description) that lead to skilled human movement

3. Psychological level Physiological level Motor Control: Questions • How do we control how much force we produce ? • What aspects of a movement are remembered to help recall a movement ? • # of motor units • rate coding • spatiallocation • effector used

4. Motor Learning involves changes in the execution of the events (physiological or behavioral/ psychological description) that lead to improvements (skilled) human movement

5. Motor Learning: Questions • Can we become more efficient in the way we produce force? Can we recruit motor units differently with practice? Can we use different frequency to recruit units? Do we change the manner in which we remember a movement ? Do we use different information about movement to remember it change (spatial features of movement followed by motor features (flexion-extension)

6. Motor Development study of changes in human movement behavior across the lifespan and the influence of these changes on human motor performance (p. 238) – We will get to this in a later section

7. Measuring Motor Control • Latency Measurements • Reaction Time • assessment of planning operations that contribute to organizing/planning a movement • Movement Time • assessment of movement implementation

8. Measuring Motor Control • Error Measures • Absolute Error • absolute deviation from a target • Constant Error • movement bias • Variable Error • movement variability

9. Measuring Motor Control • Movement Quality • Kinematics • Kinetics • Electromyography Position, velocity, acceleration, jerk (see biomechanics) Force, torque (see biomechanics)

10. Controlling Movement • Open-Loop (memory-driven) movements are completely pre-planned and subsequent feedback during the movement doesn’t change the nature of the plan (e.g., traffic lights)

11. Using Reaction Time to examine movement planning Warning “GO” Initiation Termination foreperiod RT MT

12. Perception Decision Motor Plan I O Sternberg’s (1969) planning model Reaction Time

13. Perception: SRT O O O O O O E O O O O O O O O O O O O O F F F F F F E F F F F F F F F F F F F F YES NO YES NO Plot reaction time for simple and complex perceptual cases

14. Perception in Real World

15. Decision-making: CRT

16. Decision-making: CRT RT

17. Choice impacted by Compatibility

18. Real World Compatibility Effects

19. Real World Compatibility Effects

20. Motor Plan: Movement Complexity Say /ba/ when the circle changes color Say /ba/ x 4 when circle changes color

21. Motor Plan: Movement Complexity RT RT in this case is time to start to say /ba/

22. Simplifying Movement Planning • Using feedback or closed-loop processing

23. Closed-Loop Control: Evidence Proportion of Targets missed Required Movement Time between Targets Keele and Posner (1968)

24. Perception Decision Motor Plan I O Closed and Open-Loop Control Closed Open

25. Fitts and Posner’s Stages of Learning • Cognitive • high verbalization • Associative • fine-tuning • Autonomous • attention-free Closed-loop Open-loop

26. Distinguishing Performance from Learning • Performance (or acquisition) • Learning • retention of what is practiced • generalizibility of what is practiced

27. Transfer Paradigm Acquisition Retention (transfer)

28. Importance of Practice: Anecdotal • “It appears that the patient will require much more opportunity to practice if motor control is to improve” (Duncan, 1997). • “Skill acquisition is impossible without practice” (Winstein, 1997). • Practice is repetition without repetition (Bernstein, 1967). • Practice problem-solving is more effective for learning than simply repeating the solution (Lee et al., 1994)

29. Importance of Practice • Power law of practice: Practice Extent • Composition and Scheduling of practice

30. Pre-practice considerations • Pre-practice Considerations • motivation for learning • making the task seem important (rationale) • goal setting (see Fig 11.1 Schmidt & Lee) • Verbal information (overused, Wulf & Weigelt, 1997) • perceptual presentations better than verbal

31. Verbal instructions can sometimes interfere (implicit learning) DV: Amplitude Frequency IV: Instruction No Instruction

32. Verbal instructions can sometimes interfere (implicit learning)

33. Change in RT with practice

34. Change in RT with practice

35. Power Law of Practice • The power law of practice is a very general law in human cognition, and in particular in human learning. The higher the level of expertise and the time spent on the task, the more difficult it is to improve (principle of diminishing returns). • Previous graphs reveal a typical example of data showing a power law (first graph). An interesting feature of the power law is that , when data are plotted by taking their logarithms, they are well fitted by a straight line. (second graph).

36. Can we make a practice trial more useful? • Practice Composition • Practice Variability • Mental Practice • Part vs. Whole Practice • Practice Scheduling • Practice Distribution • Contextual Interference

37. Practice Variability vs. Specificity ACQRETTRAN Specificity AAAAAAAA A E BBBBBBBBB B E CCCCCCCCC C E Variable AAABBBCCC ABC E

38. Practice Specificity or Variability?

39. Mental Practice • Skill acquisition (?) • Skill Maintenance (?) • Arousal Regulation (√) • Planning and event management (√) • Stress Management (√)

40. Whole vs. Part Practice • Nature of the Skill • task component interdependence • Capability of Learner • beginners, low aptitude • Organization of Parts • Segmentation (progressive part), simplification, fractionation

41. Key for whole is Interdependence of Parts

42. Practice Distribution: Using Time • How to best use 60 hours of training to maximize performance and learning? (e.g., 2-a-days) 2 Session 1 Session 1 hour 12 weeks 6 weeks 6 weeks 3 weeks 2 hour

43. Baddeley & Longman (1978)

44. Correct # of Keystrokes as a function of practice distribution

45. Can this work with verbal material: Melton (1970)

46. Structuring Variability: Contextual Interference ACQRETTRAN Specificity AAAAAAAA A E BBBBBBBBB B E CCCCCCCCC C E Variable 1 AAABBBCCC ABC E Variable 2 ABCBCACAB ABC E

47. A practical Example : Badminton

48. Shea & Morgan (1979)

50. Contextual Interference: Applied Examples • Baseball (Hall et al., 1994) • Badminton (Goode & Magill, 1986; Lui, 1991) • Volleyball (Bortoli et al., 1992) • Pawlata Roll (Smith et al., 1995)