Reward actively engages both implicit and explicit components in dual force field adaptation.

Area of Science:

• Motor learning and control
• Neuroscience
• Human adaptation

Background:

• Motor learning involves unsupervised, supervised, and reinforcement mechanisms.
• Reward-based learning (reinforcement) is known to improve motor adaptation, but its precise influence on underlying processes remains unclear.

Purpose of the Study:

• To investigate how reward presence impacts dual motor adaptation to opposing dynamics.
• To differentiate the effects of reward on implicit and explicit learning components during adaptation.

Main Methods:

• Participants underwent an adaptation/deadaptation/error-clamp paradigm with varying reward levels.
• Dual adaptation to two opposing force fields was assessed in reward and control groups.
• Triple-rate models were used to analyze learning rates and retention.

Main Results:

• Both groups achieved similar final adaptation levels, predominantly implicit.
• The reward group exhibited higher fast and slow learning rates and increased fast retention.
• Differences in slow learning rates were primarily implicit, while fast learning rate differences were mainly explicit.

Conclusions:

• Reward accelerates motor learning rates and influences both implicit and explicit adaptation processes.
• Reward primarily impacts the fast learning rate explicitly and the slow learning rate implicitly.
• Reward enhances initial learning rates and early adaptation timescales in dual force field tasks.