Lifespan development of postural control shows as an inverted U-shaped function with optimal performance in young adults and similar levels of underperformance in children and older adults. However, similarities in children and older adults might conceal differences in underlying control processes. We mapped out age-related differences in postural control using center-of-pressure trajectories of 299 participants ranging from 7 to 81 years old in three tasks: stable stance, compromised vision, and narrowed base of support. Summary statistics (path length, ellipse area) replicated the well-known U-shape function also showing that compromising vision and narrowing the base of support affected older adults more than children. Stabilogram diffusion analysis (SDA) allows to assess postural control performance in terms of diffusion at short (< 1 s) and longer timescales. SDA parameters showed the strongest short-term drift in older adults, especially under compromised vision or narrowed base of support conditions. However, older adults accommodated their poor short-term control by corrective adjustments as reflected in long-term diffusion under eyes closed conditions and initiating anti-persistent behavior earlier compared with children and young adults in tandem stance. We argue that these results highlight the adaptability of the postural control system and warrant a reinterpretation of previous postural control frameworks.

IntroductionThe present study explored age effects and the coupling of sensorimotor and cognitive functions in a stratified sample of 96 middle-aged and older adults (age 45-86 years) with no indication of mild cognitive decline. In our sensorimotor tasks, we had an emphasis on listening in noise and postural control, but we also assessed functional mobility and tactile sensitivity.MethodsOur cognitive measures comprised processing speed and assessments of core cognitive control processes (executive functions), notably inhibition, task switching, and working memory updating. We explored whether our measures of sensorimotor functioning mediated age differences in cognitive variables and compared their effect to processing speed. Subsequently, we examined whether individuals who had poorer (or better) than median cognitive performance for their age group also performed relatively poorer (or better) on sensorimotor tasks. Moreover, we examined whether the link between cognitive and sensorimotor functions becomes more pronounced in older age groups.ResultsExcept for tactile sensitivity, we observed substantial age-related differences in all sensorimotor and cognitive variables from middle age onward. Processing speed and functional mobility were reliable mediators of age in task switching and inhibitory control. Regarding coupling between sensorimotor and cognition, we observed that individuals with poor cognitive control do not necessarily have poor listening in noise skills or poor postural control.DiscussionAs most conditions do not show an interdependency between sensorimotor and cognitive performance, other domain-specific factors that were not accounted for must also play a role. These need to be researched in order to gain a better understanding of how rehabilitation may impact cognitive functioning in aging persons.

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Objectives: Adults’ most common complaint relates to understanding speech in noisy environments. Hearing aids can compensate for sensory loss but do not restore hearing to normal. Listening training has the potential to partially remediate these problems. In this study, we propose and evaluate a Flemish version of a listening training paradigm, which involves the use of cognitive control as well as auditory perception. The paradigm entails a discrimination task where participants are cued to attend to one of two concurrent talkers with target speakers randomly varying between a female and a male voice. We evaluate learning effects, different scenarios, and masking types. Design: In total, 70 young and 54 middle-aged adults participated in this study. Each adult performed one or more conditions. Participants’ hearing was screened before participation, all middle-aged adults passed a cognitive screening task. Results: Analyses indicated learning effects across scenarios that were similar in terms of speech intelligibility. Our results indicated better speech intelligibility when the female speaker was the target, but speech intelligibility did not differ when the target was the male speaker. An unintelligible masker noise results in worse speech intelligibility than a competing talker masker. Our results suggest that listeners could use an intensity cue to identify and/or select the target speaker when presented at a lower signal to noise ratio (SNR). Error analysis suggested higher cognitive control demands when the target and masker were presented at similar levels (i.e., around 0 dB SNR). The addition of independent trials with the intensity of target and masker reversed improved speech intelligibility. Inhibitory control, but not task switching, was reliably correlated with listening performance. Conclusions: The proposed paradigm turned out to be feasible and practicable, demonstrating its potential for training speech intelligibility in noise. We believe that this training paradigm can generate real-life benefits including for persons with hearing loss. This latter application awaits future evaluation.