Estimating the implicit component of visuomotor rotation learning by constraining movement preparation time

Area of Science:

• Motor control
• Cognitive neuroscience
• Human sensorimotor adaptation

Background:

• Accurate movement relies on implicit learning and explicit reaiming to correct sensory feedback errors.
• Previous methods to dissociate implicit and explicit learning include self-report of aiming directions and manipulating preparation time.

Purpose of the Study:

• To directly compare self-report and preparation time constraints for isolating implicit visuomotor rotation learning.
• To investigate if preparation time constraints suppress explicit reaiming during adaptation to visuomotor rotation.

Main Methods:

• Participants performed a visuomotor rotation task under different conditions.
• Methods compared: 1) self-reporting aiming directions versus actual movement and target directions, and 2) manipulating movement preparation time.
• Implicit learning was estimated by error reduction during adaptation and during trials without visual feedback.

Main Results:

• Restricting preparation time suppressed explicit reaiming, especially with broad target distributions, yielding implicit learning estimates similar to self-report.
• Self-reporting aiming directions led to less implicit learning when measured during no-feedback trials, suggesting reporting influences learning.
• Reaiming is possible even with short preparation times, particularly with narrow target distributions.

Conclusions:

• Restricting preparation time is a viable method to suppress explicit reaiming and estimate implicit visuomotor learning.
• The act of reporting aiming directions may interfere with the extent or persistence of implicit learning.
• This study provides a method for estimating implicit visuomotor learning without relying on potentially confounding self-report measures.