Explicit and implicit contributions to learning in a sensorimotor adaptation task.

Area of Science:

• Cognitive Neuroscience
• Motor Control
• Human Learning

Background:

• Visuomotor adaptation is traditionally viewed as an implicit process driven by sensory prediction errors updating a forward model.
• Human learning also involves explicit processes, such as utilizing verbal instructions and strategies.

Purpose of the Study:

• To investigate the interplay between explicit and implicit learning during visuomotor adaptation.
• To determine how instructions and error feedback modulate explicit and implicit learning contributions.

Main Methods:

• A novel task design allowed continuous verbal reports of aiming direction during visuomotor rotation learning.
• Directly measuring aiming direction enabled time-course analysis of explicit learning and isolation of implicit learning via subtraction.

Main Results:

• Explicit learning, driven by target error, showed rapid initial adjustments in aiming direction.
• Implicit learning, driven by sensory prediction error, exhibited slow, monotonic progression.
• Continuous error feedback amplified implicit learning while reducing explicit learning amplitude.
• Instructions had a minor effect on initial learning rate and implicit learning.

Conclusions:

• Visuomotor adaptation results from the dynamic interplay between explicit learning (target error) and implicit learning (prediction error).
• Both explicit and implicit learning mechanisms are crucial for effective visuomotor adaptation, even without explicit instruction.