Maximizing Motor Learning: Repetition, Duration, Frequency

The article highlights:

• The effectiveness of task-specific repetitive practice for stroke recovery
• The importance of repetitions in establishing stable neural pathways for specific tasks
• The effectiveness of shorter, frequent practice sessions for motor learning.

Task-specific practice

Intensive, task-specific rehabilitation has been found to be particularly effective in promoting recovery after a stroke. This involves practicing specific movements or activities repetitively and in a structured manner, with the goal of helping the brain rewire and adapt to the new demands being placed upon it.

When we repeatedly perform a movement, such as reaching for an object with our upper limb, the brain forms a pattern of activity that corresponds to that movement, known as an engram. The engram involves the coordinated activity of multiple brain regions, including the motor cortex and sensory cortex. These regions work together to create a neural pathway that allows us to execute the movement smoothly and efficiently.

Through a process called synaptic plasticity, the neural pathway becomes strengthened as the movement is repeated. This involves the strengthening and weakening of connections between neurons in response to activity patterns. The more frequently a particular pathway is activated, the stronger the connections become, making it easier for the brain to activate the pathway in the future.

Rehabilitation research has shown that stroke recovery progresses slowly and incrementally, and the gains may not be immediately noticeable on a daily basis. However, over a period of a week or a month, these gains become more evident when compared to the baseline. Repetitive practice is thus a crucial component of rehabilitation after a stroke or other injury that affects movement.

Over time, the strengthened neural pathway becomes more efficient and automatic, requiring less conscious effort to execute the movement. Shorter but more frequent practice sessions have been found to be more effective for motor learning, as they allow for more repetitions and prevent fatigue. Consistent rehabilitation over a longer period of time leads to significant improvements in motor function.

The number of repetitions

The number of repetitions required to establish a stable engram for a specific task can vary depending on factors such as task complexity, prior experience, and training intensity. However, research generally suggests that several thousand repetitions are necessary to establish a well-defined engram. For example, participants in a study required an average of 4,000 to 5,000 repetitions to reach a performance plateau while learning a complex motor task involving moving a cursor on a computer screen. It's important to note that simply repeating a task without paying attention to movement details or feedback from the body may not be as effective as practicing with focused attention and deliberate practice.

Task duration and frequency.

Shorter but more frequent practice sessions may be more effective for motor learning than longer but less frequent sessions. In a study by Kantak and Winstein (2012), individuals who practiced a motor task for 30 minutes per day, 5 days per week, showed greater improvements in motor performance than those who practiced for 60 minutes per day, 3 days per week. The authors suggest that shorter but more frequent practice sessions allow for more frequent consolidation and reconsolidation of motor memories.

References:

Krakauer, J. W., & Shadmehr, R. (2006). Consolidation of motor memory. Trends in neurosciences, 29(1), 58-64.

Karni, A., Meyer, G., Jezzard, P., Adams, M. M., Turner, R., & Ungerleider, L. G. (1995). Functional MRI evidence for adult motor cortex plasticity during motor skill learning. Nature, 377(6545), 155-158.

Kantak, S. S., & Winstein, C. J. (2012). Learning-performance distinction and memory processes for motor skills: a focused review and perspective. Behavioural brain research, 228(1), 219-231.

Written by Natanael Dobra - Communicative Disorders Assistant (CDA)