Asymmetric interlimb transfer of concurrent adaptation to opposing dynamic forces

Area of Science:

• Motor control and learning
• Neuroscience
• Biomechanics

Background:

• Interlimb transfer of motor skills is well-established.
• Unimanual adaptation to opposing environments is possible with distinct workspaces.
• Previous research focused on single dynamic force adaptation.

Purpose of the Study:

• To investigate if adapting to opposing velocity-dependent viscous forces with one arm enhances the other arm's performance.
• To determine if interlimb transfer occurs via extrinsic (spatial) or intrinsic (joint-based) coordinative systems.

Main Methods:

• Subjects adapted to opposing viscous forces presented in different target locations.
• Performance was measured by correlating speed profiles of movements.
• Interlimb transfer was tested from dominant to non-dominant (D --> ND) and vice-versa (ND --> D) across intrinsic and extrinsic systems.

Main Results:

• Significant adaptation to opposing forces was observed within the first epoch.
• Interlimb transfer was found exclusively from the dominant to the non-dominant limb.
• This transfer occurred only across an intrinsic coordinative system.

Conclusions:

• Interlimb transfer of opposing viscous forces is possible.
• The transfer mechanism appears to rely on an intrinsic, joint-based coordinative system.
• Motor information transfer can be more complex than previously thought, involving intricate representations.