Partial Repetition Costs are Reduced but not Eliminated with Practice

Area of Science:

• Cognitive Psychology
• Neuroscience
• Human Action Planning

Background:

• Intervening events often interrupt planned actions, requiring rapid adaptation.
• Action execution can be delayed when action plans share features, a phenomenon known as partial repetition cost (PRC).
• PRCs are hypothesized to stem from 'code confusion' within working memory (WM).

Purpose of the Study:

• To investigate if extensive practice reduces or eliminates PRCs.
• To test the 'code confusion' hypothesis of PRCs by reducing WM reliance through training.
• To examine the impact of stimulus-response (S-R) training on action plan interference.

Main Methods:

• Participants performed a partial repetition (PR) task involving retained and intervening action plans.
• Action plans were manipulated to either partly overlap or not overlap.
• Stimulus-response (S-R) training was administered for 0, 4, and 8.5 sessions before the PR task.

Main Results:

• Extensive practice significantly reduced PRCs.
• PRCs were not completely eliminated even after substantial training.
• Reduced PRCs suggest action plans become more specific and less WM-dependent with practice.

Conclusions:

• Practice modulates interference between action plans, supporting memory models where actions become more distinct.
• Findings indicate that while practice mitigates WM load, complete elimination of PRCs may require further mechanisms.
• The study advocates for broader applications of PR tasks and integrating formal memory model structures into action plan research.