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Удержание и обновление вербального и невербального материала в рабочей памяти при здоровом старении
Background.
Working memory (WM) declines with ageing. Despite a large body of relevant studies, changes in verbal and nonverbal WM, relevant specifically for healthy aging, and their brain correlates, remain understudied.Objectives. Our study aimed to analyse changes in maintenance and updating of verbal and nonverbal material in WM in healthy ageing (i.e., the absence of cognitive decline, neurological and mental disorders, as well as the history of cardiovascular and cerebrovascular events and oncological diseases).
Study Participants.
The final groups were equivalent in terms of education level and gender composition and comprised 16 older (65.7 ± 4.4 years) and 16 younger (23.3 ± 4.9 years) right-handed participants.
Methods.
We analysed the behavioural data from the project wherein the brain activity was registered via functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) while the participants performed maximally comparable verbal and nonverbal versions of the Sternberg and n-back tasks developed by us earlier. This was done to overcome the methodological limitations of previous studies which used verbal and nonverbal WM tasks that addressed different processes (e.g., updating of verbal or maintenance of non-verbal material in WM), and had different structure, stimuli, and difficulty. Neurophysiological data were not analysed in the current article.
Results.
Older participants demonstrated slower responses in all tasks than the younger participants. Response accuracy in the Sternberg task and the 0-back task was independent of age, whereas it decreased in the 2-back task by 5–10% in the older participants compared to the younger group. Some evidence in favour of a more prominent decrease of nonverbal vs. verbal WM in older participants was observed.
Conclusions.
Maintenance of material in WM is not affected by healthy ageing. Decline in updating observed in high WM load may be considered as a true age-related change of WM.