Handedness can be explained by a serial hybrid control scheme

Area of Science:

• Neuroscience
• Motor Control
• Biomechanics

Background:

• Previous research suggests specialized motor control for dominant and nondominant arms.
• A hybrid control scheme was previously proposed for single-joint movements.

Purpose of the Study:

• To investigate interlimb differences in multi-joint reaching movements using a computational framework.
• To test the hypothesis of specialized motor control (predictive vs. impedance) for dominant and nondominant arms.

Main Methods:

• Applied a computational framework modeling predictive and impedance control mechanisms.
• Analyzed multi-joint reaching movements in the horizontal plane for both arms.
• Modeled the switch-over time between predictive and impedance control modes.

Main Results:

• Nondominant arm trajectories showed an early switch to impedance control near peak velocity.
• Dominant arm trajectories were best fit with a late switch to impedance control during deceleration.
• Results support distinct motor control specializations for each arm.

Conclusions:

• The dominant arm is specialized for predictive control of limb dynamics.
• The nondominant arm is specialized for impedance control mechanisms.
• A computational model operationally defines handedness in multi-joint movements.