Postural Complexity during Listening in Young and Middle-Aged Adults

Postural behavior has traditionally been studied using linear assessments of stability (e.g., center of pressure ellipse area). While these assessments may provide valuable information, they neglect the nonlinear nature of the postural system and often lead to the conflation of variability with pathology. Moreover, assessing postural behavior in isolation or under otherwise unrealistic conditions may obscure the natural dynamics of the postural system. Alternatively, assessing postural complexity during ecologically valid tasks (e.g., conversing with others) may provide unique insight into the natural dynamics of the postural system across a wide array of temporal scales. Here, we assess postural complexity using Multiscale Sample Entropy in young and middle-aged adults during a listening task of varying degrees of difficulty. It was found that middle-aged adults exhibited greater postural complexity than did young adults, and that this age-related difference in postural complexity increased as a function of task difficulty. These results are inconsistent with the notion that aging is universally associated with a loss of complexity, and instead support the notion that age-related differences in complexity are task dependent.

Automated summary

The traditional linear assessments of postural behavior neglect the nonlinear nature of the postural system and can lead to the conflation of variability with pathology. Assessing postural complexity during ecologically valid tasks provides unique insight into the natural dynamics of the postural system. In this study, postural complexity was assessed using Multiscale Sample Entropy in young and middle-aged adults during a listening task, with results showing that middle-aged adults exhibited higher postural complexity and that this difference increased with task difficulty.