The nervous system tunes sensorimotor gains when reaching in variable mechanical environments.

Area of Science:

• Neuroscience
• Motor Control
• Biomechanics

Background:

• Human movements frequently encounter unpredictable mechanical disturbances.
• These disturbances can compromise the accuracy and success of actions.
• Understanding the nervous system's adaptive strategies is crucial for motor control research.

Purpose of the Study:

• To investigate how the nervous system adjusts control strategies during reaching movements under variable mechanical disturbances.
• To identify the relationship between movement characteristics, sensory feedback, and disturbance variability.

Main Methods:

• Healthy participants performed reaching movements while exposed to randomly varying mechanical disturbances.
• Movement kinematics and sensory feedback responses (proprioceptive and visual) were analyzed.
• Control strategies were inferred based on movement adjustments and feedback sensitivity.

Main Results:

• Participants modified their motor control strategies to enhance movement robustness against disturbances.
• Reaching movements became faster in the presence of variable disturbances.
• Responses to proprioceptive and visual feedback increased and were tuned to disturbance variability.

Conclusions:

• The nervous system employs a flexible continuum of control strategies to manage mechanical disturbances.
• Increased responsiveness to sensory feedback is a key adaptation for maintaining performance.
• These findings offer insights into the neural mechanisms underlying adaptive motor control.