Whole body adaptation to novel dynamics does not transfer between effectors

Area of Science:

• Neuroscience
• Motor Control
• Biomechanics

Background:

• The brain coordinates arm movements and standing posture.
• Postural control can utilize information from adapted arm movements.
• It is unknown if postural control adapts independently of arm control.

Purpose of the Study:

• Investigate if postural control can be adapted and controlled independently of arm control.
• Examine the transfer of motor learning between arms for both arm and postural control.
• Determine the role of error size and consistency in motor adaptation.

Main Methods:

• Subjects performed reaching movements with a robotic arm while standing.
• Novel force field perturbations were introduced abruptly or gradually.
• Adaptation was assessed during dominant arm reaching and then transferred to nondominant arm reaching.

Main Results:

• Neither arm control nor postural control showed evidence of transfer between the dominant and nondominant arms.
• Motor adaptation occurred even with small errors, indicating error size and consistency are important.
• Postural adaptation was dependent on concurrent arm movement dynamics.

Conclusions:

• Adapted postural control cannot be transferred independently of arm control in this task.
• Whole-body postural movement planning is linked to concurrent arm task dynamics.
• Error signals play a crucial role in driving motor adaptation.