Prior uncertainty impedes discrete locomotor adaptation

Area of Science:

• Neuroscience
• Biomechanics
• Motor Control

Background:

• Environmental uncertainty's effect on locomotor adaptation is not well understood.
• Uncertainty may aid or impede motor learning by altering movement control strategies.

Purpose of the Study:

• To investigate how unpredictable environmental uncertainty impacts adaptation to a consistent force field.
• To compare locomotor adaptation in participants exposed to perturbations versus a control group.

Main Methods:

• Participants adapted to a robotic force field after experiencing unpredictable balance perturbations.
• Assessed center of mass (COM) trajectory, anticipatory postural adjustments (COM lateral offset), and step width.
• Compared a Perturbation group to a Non-Perturbation control group.

Main Results:

• The Perturbation group showed greater initial disruptions in COM trajectory when entering the force field.
• Only the Non-Perturbation group fully adapted their COM trajectory to baseline levels.
• The Perturbation group demonstrated impaired adaptation in COM lateral offset and step width.

Conclusions:

• Exposure to unpredictable perturbations impedes subsequent sensorimotor adaptation to consistent environmental demands.
• Unpredictable environmental uncertainty negatively affects the ability to learn and adapt movements.