Cortical tracking of postural sways during standing balance

Area of Science:

• Neuroscience
• Human Motor Control
• Systems Neuroscience

Background:

• Maintaining upright stance relies on integrating sensory information (visual, vestibular, somatosensory-proprioceptive) for postural control.
• The specific role of the cerebral cortex in monitoring and controlling postural sway remains unclear.

Purpose of the Study:

• To investigate whether postural sway is encoded in ongoing cortical oscillations, forming corticokinematic coherence (CKC).
• To explore the involvement of the cerebral cortex in the closed-loop control of standing balance.

Main Methods:

• Recorded center-of-pressure (CoP) fluctuations and electroencephalographic (EEG) cortical activity in healthy participants.
• Manipulated sensory information during balance tasks to challenge postural control.
• Analyzed the relationship between cortical activity and CoP fluctuations to identify CKC.

Main Results:

• Postural sway is represented in ongoing cortical activity as CKC at 1-6 Hz during challenging balance conditions.
• Time delays in CKC suggest the brain monitors CoP velocity and controls position via afferent and efferent pathways.
• CKC predicted increased instability when sensory information was altered, indicating behavioral relevance.

Conclusions:

• Human sensorimotor cortical areas actively participate in the closed-loop control of standing balance under challenging conditions.
• Corticokinematic coherence (CKC) serves as a potential neurophysiological marker for cortical involvement in balance maintenance.