Random Practice Enhances Retention and Spatial Transfer in Force Field Adaptation.

Area of Science:

• Motor Learning and Control
• Neuroscience
• Robotics

Background:

• The contextual-interference effect, well-studied in motor skill acquisition, remains underexplored in motor adaptation.
• Understanding this effect is crucial for optimizing training protocols in rehabilitation and sports.

Purpose of the Study:

• To investigate the presence of the contextual-interference effect in force field adaptation.
• To examine its impact on motor retention and spatial transfer.
• To model the observed phenomena using state-space models and the forgetting-and-reconstruction hypothesis.

Main Methods:

• Thirty-two participants were assigned to either random or blocked practice schedules for reaching movements in a force field.
• Motor retention and spatial transfer were assessed at 10 minutes and 24 hours post-practice.
• Participant-specific 4-slow-1-fast state-space models were fitted to adaptation data.

Main Results:

• The blocked group showed faster initial adaptation, but performance did not differ at practice conclusion.
• The random group exhibited superior short-term (10 min) retention and interpolation transfer.
• The random group also demonstrated better transfer to shifted targets at both 10 min and 24 h, though long-term retention showed no significant differences.

Conclusions:

• The contextual-interference effect is partially evident in force field adaptation, influencing practice dynamics, short-term retention, and spatial transfer.
• State-space models offer valuable insights into the mechanisms underlying the contextual-interference effect in this context.