Cortical adaptations in Tai Chi practitioners during sensory conflict: an EEG-based effective connectivity analysis of postural control.

Background: Tai Chi (TC) is recognized for enhancing balance and postural control. However, studies on its effects on the central nervous system are limited and often involve static experiments despite the dynamic nature of TC. This study addressed that gap by examining cortical network activity during dynamic, multisensory conflict balance tasks. We aimed to determine whether long-term TC practice leads to neuroplastic changes in brain connectivity that improve sensory integration for postural control.

Methods: Fifty-two young adult participants (long-term TC practitioners = 22; non-practitioners = 30) performed balance tasks under sensory congruent and conflict conditions using a virtual reality headset with a rotating supporting surface. EEG was performed, and generalized partial directed coherence was used to assess directed functional connectivity in the mu rhythm (8-13 Hz) between predefined regions of interest (ROIs) in the cortex implicated in sensory and motor integration. Graph-theoretic measures (in-strength and out-strength) indexed the total incoming and outgoing connection strengths for each region. Statistical analysis used mixed-design ANOVAs (Group × Condition) to compare balance and connectivity measures.

Results: TC practitioners demonstrated significantly better postural stability under both sensory conditions, with a reduced sway area. EEG analysis revealed that increased sensory conflict decreased the global efficiency of the visual integration network but increased that of the somatosensory integration network. Furthermore, TC practitioners demonstrated enhanced out-strength of the somatosensory cortex and lower out-strength of the right posterior parietal cortex (PPC) compared to non-practitioners.

Conclusions: Long-term TC practice is associated with quantifiable neuroplastic changes in mu-band cortical effective connectivity, specifically enhanced information outflow from somatosensory reduce parietal influence regions. Our findings demonstrate central mechanisms by which TC practice may improve balance, providing neuroengineering evidence for TC as a neuroplasticity-driven balance intervention.