Cognition and brain network connectivity in timed up & go performance

Gait performance depends on numerous aspects of brain functioning that are also relevant to key cognitive processes throughout the lifespan. The Timed Up and Go (TUG) test has been shown to be a reliable tool for assessing age-related mobility changes and risk of falls in older adults. This study aimed to predict TUG performance using motor-cognitive inter-network connectivity, cognitive performance and socio-demographics. 189 participants without cognitive impairment were included. Mobility was measured with the TUG through a wireless inertial sensor device. Functional connectivity between the somatomotor hand, cerebellar, and cognitive-related networks was assessed using pairwise correlations among 264 predefined regions assigned to large-scale functional networks. Connectivity between networks was summarized by averaging Fisher z-transformed values across all ROI pairs linking each network pair. Three linear regression models were constructed including the dependent variables TUG total time, turning time and turning peak-angular velocity (PAV) and the independent variables age, sex, years of education, memory and executive performance, and inter-network connectivity patterns. Somatomotor hand - ventral attentional and cerebellar - DMN inter-network connectivity were significant predictors of TUG total time. Memory performance, somatomotor hand - salience and -cingulo opercular inter-network connectivity were significant predictors of turning time. Age, years of education, somatomotor hand - dorsal attentional and cerebellar - cingulo opercular network activation were significant predictors of turning PAV. Findings indicate different contributions of attentional systems to gait performance in aging.