Effects Of Tai Chi Chuan Exercise On Brain Function As Assessed By Near-infrared Spectroscopy

Tai Chi Chuan(TCC)is an intangible cultural heritage in China and is beneficial to human health.Early studies have shown that TCC contributes to the rehabilitation of cognitive disorders and increases blood oxygen concentration levels in the parietal and occipital brain areas;however,the mechanism of TCC training on brain function remains poorly understood.This study hypothesize that TCC has altered cognitive function and aims to explore the effects of TCC on functional connection and effective connection of the prefrontal cortex(PFC).The participants were 55 healthy right-handed subjects aged 60-70 years.Among which,23 were experienced Chen-style TCC practitioners(TCC group),and 32 were demographically matched healthy controls(control group).Near-infrared spectroscopy(NIRS)signals were analyzed in five frequency intervals:?,0.6-2 Hz;?0.145-0.6 Hz;?,0.052-0.145 Hz;?,0.021-0.052 Hz,and V,0.0095-0.021 Hz.Functional and effective connections were calculated using wavelet-based coherence analysis and dynamic Bayesian inference method,respectively.The wavelet amplitude results showed that TCC training could induce activations of PFC,motor cortex(MC),and occipital cortex(OC).The significant difference of the wavelet phase coherence values indicated that short-term TCC training benefitted MC and OC;moreover,long-term TCC training involved the PFC in motor control and improved the connection of PFC,MC and OC in myogenic activity,sympathetic nervous system,and endothelial cell metabolic activities.Therefore,TCC practice could reduce brain lateralization and enhance integration between the brain regions.This result relayed the ability of TCC training to improve cognitive ability and its potential against memory decline.The resultant effective connections showed that long-term TCC training enhances the control of sympathetic and parasympathetic innervations in the PFC and MC.Furthermore,TCC affected the interaction among different brain regions,and this enhancement was maintained in TCC practitioners.Lastly,this study indicated that functional NIRS is an optimal cortical imaging monitoring tool for evaluating the brain function of TCC practitioners in resting and moving environments and helps improve the TCC training strategy.