Trade-off between frequency and precision during stepping movements: Kinematic and BOLD brain activation patterns

Area of Science:

• Neuroscience
• Motor Control
• Human Locomotion

Background:

• The central nervous system adapts locomotor patterns for diverse gaits and velocities.
• External pacing stimuli reveal a frequency-precision trade-off in human locomotion, suggesting specialized control centers.

Purpose of the Study:

• To explore the neural mechanisms underlying adaptive locomotion control.
• Investigate brain activity and lower limb kinematics during externally paced stepping.

Main Methods:

• Healthy subjects received visual guidance to follow three stepping frequencies on a custom treadmill.
• Simultaneous recording of blood-oxygen-level-dependent (BOLD) responses and lower limb kinematics.

Main Results:

• Stepping precision and stability improved with increased frequency, indicating a shift from reactive to predictive control.
• Brain activity showed significant differences in parietal and cerebellar regions correlating with stepping precision and stability.
• Neural correlates for precision involved the insula, cerebellum, pons, and inferior olivary nucleus; stability involved a distributed network.

Conclusions:

• Locomotion control transitions from reactive (subcortical) at lower paces to predictive (cortical) at higher paces.
• Distinct neural networks support stepping precision and stability, adapting to changing environmental demands.