What is all the fuss about Principles of Motor Learning (PML) and Childhood Apraxia of Speech?

“Motor learning refers to the practice or experience leading to relatively permanent changes in the capability of movement (Schmidy & Lee 2005).

As a child, I was a figure skater, soccer player, baton twirler, horseback rider, cross country runner, hurdler, and skier (which might be one of the reasons I had a knee replacement this last year at only 46).  The first time on skates, I slid and fell.  I didn’t know how to move my legs in order to glide on the blades.  At the height of my figure skating, I was landing double jumps and gracefully gliding across the ice (well most of the time).  I learned how to figure skate by learning how to move my body in ways to create jumps, spins, and footwork patterns across the ice.  When I look back, I can see how integral motor learning was to my skating and how some of the Principles of Motor Learning were a component of my growth.

The Principles of Motor Learning are not unique to Childhood Apraxia of Speech.  These principles were derived from studies that involved nonspeech motor tasks, most with intact motor systems.  It is hypothesized that these principles can be applied to support disordered motor speech systems.  There is growing research and clinical experience in the efficacy of using these principles for Childhood Apraxia of Speech, but further research and clinical experience is needed.

So what are the Principles of Motor Learning and how can I incorporate them into my practice?

First, let’s look at some of the principles of motor learning.

Practice (Learning) Versus Performance

This is an area that I feel very strongly about.  There is often the push for data, data, and more data.  But are we truly promoting learning?  Early in my career, I looked at our games, flashcards, and therapy books only to realize many of them didn’t include the learning or teaching component.  We are drilling, but are we teaching.  In the PML research for CAS, there is a distinction between acquisition (or learning) and retention.  It is important to measure if our “practice” is transferring into similar untrained movements.  So we have to give our clients the opportunity to learn and practice movement so that it generalizes.

How do we structure practice according to PML?

  1.  Practice Amounts: This has to do with the amount of time spent practicing the movements.  Are there large or small amounts of time or trials.
  2. Practice Distribution:  Mass versus distributed practice can refer to both within the session and between sessions.
    • Mass Practice = minimal time between trials or sessions. Between sessions might look like sessions schedule on Monday, Tuesday, and Wednesday.  Within-session mass practice would entail working on a target multiple times with minimal time between trials.
    • Distributed practice = greater time between trials and/or sessions.  Sessions might be distributed across multiple days in a week (i.e. Monday, Wednesday, and Friday).  Within-session there might be greater time between trials and even have other targets in between.
  3. Practice Variability: Constant versus Variable – sometimes this has to do with changing the targets, and sometimes it could just be changing the context of the target.  Below the target is
    • Constant practice has to do with practicing the same target in the same context
      • I eat a cookie
      • I eat a cookie
      • I eat a cookie
    • With variable practice, you practice different targets in different contexts.
      • I EAT a pizza
      • I eat a cookie
      • I eat a COOKIE
  4. Practice Schedule:  Blocked versus random
    • With Blocked Practice, the same target or targets are worked on in the same order and before starting a new target.  This could look like this:
      • dog, dog, dog, dog, dog
      • dog, cat, bat, dog cat, bat, dog, cat, bat
    • In Random Practice there is not a predictable order for targets.  Chosen targets are worked on in a random and unpredictable order.  This might look like this:
      • dog, cat, bat, car, mom, dog
      • cat, dog, dog, car, mom, dog
  5. Supporting Practice:  Feedback
    • Feedback TYPE: Knowledge of Results (KR) versus Knowledge of Performance (KP)
      • Knowledge of Results typically is whether production was correct or not.  For example, if a child was working on “chair” and they said “tair” you would comment “No, that was not correct”.
      • With Knowledge of Performance, the feedback is more specific.  For example, if a child said “tair” or “chair” you might comment that “I heard you say tair instead of chair, you used a “t” instead of the “ch” sound.”
    • The frequency of feedback:  Feedback is given with every production or at a high rate, or at a lower frequency.
    • The timing of feedback:  Feedback is immediate or delayed by a specific amount of time (i.e. 5 seconds).

As you may have noticed each of these principles has multiple components.  So which do I use?  When should I use random versus blocked practice?  What I have found in my research as well as practice, is that it depends on the level and needs of the individual that you are working with.  In my next post, I will share some of the research on when and how you might incorporate these different components with CAS.

PS – It is ALL about the MOVEMENT!

Resources for this article:

Rosenbek, J., Lemme, M., Ahern, M., Harris, N., & Wertz, T. “A treatment for apraxia of speech in adults.” The Journal of speech and hearing disorders 38(4), 1973, pp. 462-72.

Mass, E. et. al, “Principles of Motor Learning in Treatment of Motor Speech Disorders.” American Journal of Speech-Language Pathology, Vol. 17, 2008, pp. 277–298.