Practice

1. Practice Chapter 5

2. Performance & learning • Performance is observed, learning inferred • Performance can improve without improved learning • Learning can improve without improved performance • What is learning, really?

3. Amount of practice • Do we become less dependent on the environment, or more? • Important implications – do you practice powerlifting in front of a mirror to aid form? (Proteau & Temblay, 1998)

4. Amount of practice • As we learn, do we rely less on feedback? • Proteau’s task (1987, 1992)...

5. Amount of practice • As we learn, do we rely less on feedback? • Proteau’s typical paradigm... • Task: 90cm movement in 550msec • Condition 1: 200 trials with vision • Condition 2: 2000 trials with vision • Test condition: No vision Has also used walking (see next slide), force control, and others Sometimes as little as 20 vs. 200 trials too.

6. Amount of practice • As we learn, do we rely less on feedback? • Typical Results: The full vision practice condition typically transfers to a no vision condition badly, and this gets worse as full vision practice increases

7. Amount of practice • As we learn, we seem to rely more on the information that is present and used when we learn • For the powerlifting form example – mirrors not a good idea (Proteau & Tremblay, 1998) • Also think of learning to type, drive (shifting gear), play piano (watching fingers) and so on • “learning is specific to the source or sources of afferent information that are more likely to ensure optimal performance”

8. Amount of practice • More recent findings: • Weak vs. strong visual cues (still a reaching task) – weak vision transfers as well as no vision to a no vision condition • Weak vision encourages processing of other sources of information like proprioception

9. Amount of practice • More recent findings: • Ball interception – touch the interception point of a moving ball with the index finger • Two conditions: full vision, or ball only

10. Amount of practice Normal specificity effect when transferring to practiced trajectories • More recent findings: • Ball interception – touch the interception point of a moving ball with the index finger • Two conditions: full vision, or ball only Effect disappears in new trajectories

11. Variability of practice • Imagine you’re trying to teach catching • Should you make it as simple as possible, by choosing only one type of ball, one type of throw, one catching technique…etc… • Or not?

12. Variability of practice • Schema Theory (Schmidt, 1975) • More variability means more generalized schema for learning • Like a regression rule • Your performance of the right movement depends on the proximity of previous behavior to the desired behavior

13. Variability of practice • Supported? • Generally, I’d say so, provided key assumptions are met • Are the participants genuinely novices? • Is sufficient practice given to form a strong enough prediction rule? • Is prediction of a novel version of the task ultimately required? • See Schmidt and Shapiro (1982) for a summary • Does not imply that the governing theory is accepted • Now as for organization of variability...

14. Random Blocked Serial All A’s …then all B’s …then all C’s Who knows – it’s random! A B C Contextual interference • Practice order (3 tasks – A, B, and C) Low Amount of contextual interference High

15. Contextual interference • Practice order (3 tasks – A, B, and C) • Stimulus light goes off • Color signifies which movement pattern to perform • Pick up tennis ball • Knock down barriers • Replace tennis ball • RT and MT measured

16. Contextual Interference effect • From the classic study (Shea & Morgan, 1979) • Practice – Low CI is better (time is being measured, so smaller scores are better) • Retention – High CI is better

17. Contextual Interference • Theory • 2 primary hypotheses • Elaboration • Compare the sequence of tasks practiced within blocked and random practice – what kinds of comparisons between or among the tasks are promoted by each type of practice?

18. Contextual Interference • Theory • 2 primary hypotheses • Action plan reconstruction • Compare the sequence of tasks practiced within blocked and random practice – how long, on average, do you have to wait before the task is repeated in each practice order? • Brown-Peterson (1958), Peterson-Peterson (1960) Recall worsens as interval “A” increases A Recall improves (!) as interval “A” increases A

19. Contextual Interference • Some research examples, and some conclusions... http://www.youtube.com/watch?v=CIG3El76ltg&feature=related

20. Contextual Interference • Smith & Davies (1995) • Used a Pawlata roll • Compared progressive part learning of a full roll with either alternate (high CI) or blocked (low CI) practice • All transferred to both a full and a half roll one weeklater (score is 5 - average # attempts prior to success)

21. Contextual Interference • Now for something completely different (...and quite a bit more difficult) We’ll see that these findings may severely limit the generalization of the CI effect

22. Contextual Interference • Task: • Notice: overall duration varies across tasks; relative timing does not

23. Contextual Interference • Task: • With this task, you can vary overall duration without varying rhythm • see previous slide • Or both • Or vice versa • E.g. • 300-200-400 • 400-300-200 • and 200-300-400

24. Contextual Interference • Findings • Experiment 1: • The more consistent the practice type, the better people perform in retention and transfer

25. Contextual Interference • Findings • Experiment 2: • Feedback type has a radical effect on this outcome • Hard to see, but depending on fdbk, effect is almost reversed • Generally, whatever results in stability of RT during practice works (random practice with segment fbdk did this, & so did blocked practice w/ratio fdbk)

26. Contextual Interference • Since then... • Still celebrated as a general effect • Does not seem to be the case • Shea’s (& colleagues) work clearly important • Findings largely limited to overall timing (simple adaptations of already known movements) • Smith & Davies (1995, see also Smith, 2002, Smith et al, 2003) may be a result of negative transfer rather than CI • But these things matter too! • Subsequent work emphasizes the disconnect between simple and complex tasks...

27. Contextual Interference • Complexity as a moderator (for CI & others) A good review paper for the final

28. Part vs. Whole practice • Segmentation, fractionation, simplification, component interdependence... • Do the parts fit together naturally, or can they be easily separated? • Think of a free throw – should you practice the knee movement and the arm movement separately? • Juggling...from the annals of 257 (Spring 2000) – Knapp & Dixon (1952) revisited.

29. Part vs. Whole practice 11am class: move through practice stages quickly (get to the full juggling phase as soon as possible) 12:35pm class: practice each stage thoroughly (master each stage before moving on) Similar findings have been published by Knapp & Dixon, 1952.

30. Part vs. Whole practice • In this case, part practice of juggling didn’t work well • Seems that the skill is highly organized, and as such should not be practiced in parts • See also Hautala (1988): scarves not a good idea.