Objective To investigate the balance control abilities and cortical activation characteristics of elderly individuals under different sensory strategies. Methods From January to May,2023,19 healthy young adults and 20 elderly individuals were recruited in Changzhou as control group and experimental group,respectively.Both groups wore functional near-infrared spectroscopy(fNIRS)caps and performed balance control tasks on a balance platform under three different sensory strategies.Test A was 40 seconds of standing on a stable surface with eyes closed,Test B was 40 seconds of standing on an unstable surface with eyes open,and Test C was 40 seconds of standing on an unstable surface with eyes closed.Before and after the tests,both groups performed 40 seconds of standing on a stable surface with eyes open.The overall stability index(OSI)and cortical activation β values of the regions of interest(ROI)were measured and compared between two groups.The ROIs included the left premotor cortex(LPMC),right premotor cortex(RPMC),left sensorimotor cortex(LSMC),right sensorimotor cortex(RSMC),left prefrontal cortex(LPFC)and right prefrontal cortex(RPFC). Results There was no significant difference in OSI and β values of each ROI in Tests A and B between two groups(P>0.05).In Test C,there was a lower OSI in the experimental group(Z=-2.056,P<0.05),and there were signifi-cant differences in the β values of RSMC(t=2.623,PFDR<0.05),LPMC(Z=-2.360,PFDR<0.05)and LPFC(t=3.202,PFDR<0.05)between two groups. Conclusion Elderly individuals experience a decline in balance control abilities,accompanied by increased activation in related brain regions,when both vision and proprioception are restricted.

ObjectiveTo explore the characteristics of balance and cortical activation in older adults when performing cognition-balance dual tasks. MethodsFrom January to April, 2023, 20 healthy older adults were non-targeted recruited. They completed six tasks of close eyes & fixed platform (CF), close eyes & fixed platform & cognitive task (CFc), open eyes & sway-referenced platform (OS), open eyes & sway-referenced platform & cognitive task (OSc), close eyes & sway-referenced platform (CS), and close eyes & sway-referenced platform & cognitive task (CSc) on the Balance SD, wearing functional near-infrared spectroscopy caps. The overal stability index (OSI) was measured with Balance SD. The premotor cortex (PMC), sensorimotor cortex (SMC) and prefrontal cortex (PFC) were as regions of interest (ROIs), and the β values were calculated. ResultsThe OSI was more as CFc than as CF (Z = -2.014, P < 0.05), and was less as CSc than as CS (Z = -2.063, P < 0.05). The β values of bilateral ROIs were all more as CFc than as CF (|Z| > 2.464, |t| > 3.733, P < 0.05), and as OSc than as OS (|t| > 2.308, P < 0.05); the β value of the right SMC was more as CSc than as CS (t = -2.912, P < 0.05). The number of correct counts was less as CSc than as CFc and OSc (|Z| > 3.643, P < 0.001). ConclusionBalance has been impaired under dual tasks for older adults, while activation of cerebral cortex increases. However, for more difficult balance task, older adults would preferentially maintain postural balance under dual tasks, while cognitive performance decreases, which may be the results from no more activation of cerebral cortex under dual tasks.