Does Overpractice Improve Motor Learning?
Condition: Aging
Study type: Interventional

Summary: 
      This study contains two pilot studies: 1) one study will investigate practice dosage of a
      postural stepping task in healthy young individuals in order to determine an operational
      definition of performance plateau, and 2) the other study will investigate whether practicing
      beyond reaching a performance plateau improves learning of a postural stepping task in
      healthy older adults, compared to discontinuing practice immediately after reaching a
      performance plateau. The investigators hypothesize that the group that continues to practice
      beyond reaching their performance plateau will learn and retain the motor task better than
      the other group.
    

Detailed description: 
      What is the ideal amount, or dose, of practice needed for a person to learn a motor skill?
      Studies suggest that "more is better," but the optimal dose of motor practice is unknown.
      Motor learning is defined as a set of internal processes leading to a relatively permanent
      change in the capability for a motor skill. Older adults and people with neurological
      disorders have a critical need to learn and relearn motor skills to remain independent, but
      standard clinical rehabilitation currently provides practice doses that are insufficient to
      result in motor learning. Under-dosing of practice results in sub-optimal clinical outcomes,
      while research studies that are dosed insufficiently to identify between-group differences
      are prone to misinterpretation. Therefore, it is essential for both clinical care and for
      research that we determine the practice dose needed to optimize motor learning.

      Performance curves (i.e., plots of the average performance of a group or individual for each
      of a number of practice trials or blocks of trials) demonstrate that performance improves
      (e.g., error decreases or speed increases) during practice, until a point at which
      performance improvement begins to plateau. Additional practice provided beyond the point at
      which an individual reaches a performance plateau will be termed overpractice. Amounts of
      practice that are insufficient to reach a plateau tend not to demonstrate motor learning,
      while overpractice typically results in retention of the practiced task.

      Pilot Study #1: The first pilot study will include healthy young adults who are randomly
      assigned to practice a postural stepping task for one day, or for five consecutive days of
      practice. The investigators will use this data to determine an operational definition (i.e.,
      a mathematical definition) of performance plateau. This definition will be used to
      differentiate the groups in Pilot Study #2.

      Pilot Study #2: The second pilot study will include healthy older adults who will be divided
      into three groups: a standard of care group (i.e. very low dose), an overpractice group, and
      a no overpractice group. All groups will practice a postural stepping task. The experimental
      group will be the overpractice (OVP) group, in which each participant will complete 100%
      additional practice trials after reaching their performance plateau. In contrast, the two
      active control groups will be the no overpractice (NoOVP) group (in which each participant
      will stop practicing immediately after reaching a performance plateau), and the standard of
      care (SoC) group (in which each participant will perform one block of practice).
    

Intervention name(s): Motor Practice of a Standing Serial Reaction Time Task
Intervention type(s): Behavioral
Intervention description(s): Subjects will perform a standing serial reaction time task on a step reaction mat. Subjects will step to a series of targets, based on a series of stimuli that are presented. One trial is composed of two 12-step sequences. One of the 12-step sequences is random, while the other is a repeated sequence; sequences are presented in random order. After each trial, the subject rests for 25 seconds. Six trials equal 1 block of practice, which is followed by a 4 minute rest break. After each block, feedback is provided about average response time (RT) on all steps included in the block. One complete day of practice consists of 6 blocks of practice in which each block consists of 6 trials.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Supportive Care
Keywords: Motor Learning; Dose of Motor Practice; Postural Control; Serial Reaction Time Task; Retention; Transfer; Overpractice; Overtraining; Overlearning