Can moving in a redundant workspace accelerate motor adaptation?

Area of Science:

• Motor control
• Neuroscience
• Human movement science

Background:

• Behavioral variability can reflect beneficial exploration and learning, not just noise.
• Interindividual differences in motor learning correlate with baseline movement variability.

Purpose of the Study:

• To investigate how permitting versus constraining movement variability impacts motor learning rate within an individual.
• To determine if workspace redundancy modulates motor adaptation spatially.

Main Methods:

• Healthy young adults performed reaching movements to targets of varying shapes (arc, line) to manipulate movement variability in direction or extent.
• Motor adaptation rates to visuomotor perturbations (rotation, gain) were quantified after priming with different target shapes.

Main Results:

• Arc-shaped targets increased directional movement variability; line-shaped targets increased extent variability.
• Adaptation to visuomotor rotation was greater after priming with arc targets, while adaptation to gain change was greater after priming with line targets.
• These effects were most pronounced in workspaces with higher initial movement trajectory variability, indicating planning noise.

Conclusions:

• Workspace redundancy can spatially modulate motor adaptation.
• The degree of modulation depends on the level of planning noise within the workspace.
• Redundant workspaces may offer potential benefits for motor rehabilitation.