Interference between Flexible and Adaptive Reaching Control

Area of Science:

• Neuroscience
• Motor Control
• Human Movement

Background:

• Humans exhibit rapid motor control updates in response to contextual changes.
• Flexible control and motor adaptation are distinct but co-occur within movements, suggesting functional interaction.

Purpose of the Study:

• To investigate the interaction between flexible control and motor adaptation during human movement.
• To determine if concurrent target changes and force field adaptation interfere with motor performance.

Main Methods:

• Experiments involved human participants reaching for targets that changed in size (redundancy) under varying force field conditions.
• Step loads assessed exploitation of target redundancy.
• Force fields were introduced separately or combined with target changes.

Main Results:

• Exploitation of target redundancy was reduced when target changes occurred with force field adaptation.
• Force field adaptation magnitude decreased with the addition of step loads.
• Interference was most pronounced when all perturbations occurred simultaneously.

Conclusions:

• Flexible control and motor adaptation interact non-trivially during movement.
• These mechanisms show interdependence, particularly when engaged concurrently.
• The timescale for these interactions is during the execution of the movement.