Reexposure to a sensorimotor perturbation produces opposite effects on explicit and implicit learning processes

Area of Science:

• Neuroscience
• Motor Control
• Cognitive Psychology

Background:

• The motor system adapts to environmental changes, with faster future learning known as savings.
• Savings in sensorimotor learning are often linked to explicit memory recall.
• The contribution of implicit adaptation to savings is debated.

Purpose of the Study:

• To investigate whether implicit adaptation contributes to savings in sensorimotor learning.
• To differentiate the roles of explicit and implicit processes in motor learning and relearning.
• To examine the effects of relearning on both explicit and implicit adaptation components.

Main Methods:

• Used a visuomotor rotation task to measure explicit and implicit adaptive responses in parallel.
• Employed a protocol designed to elicit savings.
• Utilized clamped visual feedback in a second experiment to isolate implicit adaptation.

Main Results:

• The initial rate of learning was faster upon re-exposure, but this benefit was solely due to explicit re-aiming.
• Implicit adaptation, measured by aftereffects in no-feedback trials, significantly decreased after relearning.
• Relearning with clamped feedback also showed reduced adaptation and attenuated aftereffects, confirming implicit adaptation attenuation.
• Reanalysis of prior studies revealed a consistent pattern of implicit adaptation attenuation during relearning.

Conclusions:

• Explicit and implicit sensorimotor processes have opposing effects during relearning.
• Explicit learning demonstrates savings, enhancing performance upon re-exposure.
• Implicit adaptation becomes attenuated with relearning, suggesting a complex interplay between learning systems.