Leeftijdsgerelateerde veranderingen in multitasking met betrekking tot posturale controle

Maintaining balance while standing on slippery surfaces or engaging in conversation within noisy environments draws heightened attention to tasks that are typically perceived as effortless. Age-related decrements to sensory and motor functions have been suggested to induce a similar shift, going from automatic to more cognitively demanding sensorimotor processing. Multitasking studies generally support the idea of elevated interference between cognitive and sensorimotor functions in older age. However, advances in theorizing requires specifying underlying component processes to localize the sources of task interference. This dissertation aimed to uncover the mechanisms underlying cognitive-sensorimotor task interference and their age-related development. In our first study we identified component processes contributing to postural stability and their age-related changes. By adopting stabilogram diffusion analysis (SDA) as well as traditional summary measures of postural control in a lifespan sample of participants, we revealed that similarities in overall performance conceal important differences in the contributions of component processes. Older adults relied on superior long-term correction mechanisms to show overall levels of stability similar to children. In the second study, we applied the lifespan approach and SDA modeling to cognitive-sensorimotor multitasking and assessed the generalizability of age-differences in multitasking costs by comparing performance to a second multitasking context. Results indicated that the timing and quality of corrective long-term mechanisms play specific roles across different age groups and influence their adaptation to multitasking challenges. Age-related differences in multitasking costs strongly depended on the task combination, with children showing smallest task interference in the combination relying on switching, highlighting the role of cognitive control in multitasking. In the third study, we focused adult age-related changes and asked whether cognitive-sensorimotor interference already emerged in middle adulthood under ecologically relevant listening and postural control demands. Results revealed that young adults' performance remained unaffected under concurrent task demands. In contrast, while middle-aged and older adults maintained single-task levels of listening performance during multitasking, their postural stability declined substantially. SDA replicated findings of the previous study indicating long-term diffusion as a key parameter determining age-differential multitasking interference. Taken together, this dissertation significantly advances our understanding of the component processes underlying age-related differences in cognitive-sensorimotor task interference. By delineating the explanatory scope of existing multitasking models, it was illustrated how individuals across the lifespan navigate multitasking situations, highlighting both the potential as well as the limitations of compensatory strategies in older age.