Successful Working Memory Processes and Cerebellum in an Elderly Sample: A Neuropsychological and fMRI Study

Abstract

BackgroundImaging studies help to understand the evolution of key cognitive processes related to aging, such as working memory (WM). This study aimed to test three hypotheses in older adults. First, that the brain activation pattern associated to WM processes in elderly during successful low load tasks is located in posterior sensory and associative areas; second, that the prefrontal and parietal cortex and basal ganglia should be more active during high-demand tasks; third, that cerebellar activations are related to high-demand cognitive tasks and have a specific lateralization depending on the condition.MethodsWe used a neuropsychological assessment with functional magnetic resonance imaging and a core N-back paradigm design that was maintained across the combination of four conditions of stimuli and two memory loads in a sample of twenty elderly subjects.ResultsDuring low-loads, activations were located in the visual ventral network. In high loads, there was an involvement of the basal ganglia and cerebellum in addition to the frontal and parietal cortices. Moreover, we detected an executive control role of the cerebellum in a relatively symmetric fronto-parietal network. Nevertheless, this network showed a predominantly left lateralization in parietal regions associated presumably with an overuse of verbal storage strategies. The differential activations between conditions were stimuli-dependent and were located in sensory areas.ConclusionSuccessful WM processes in the elderly population are accompanied by an activation pattern that involves cerebellar regions working together with a fronto-parietal network.

Atlas55+: Brain Functional Atlas of Resting-state Networks for Late Adulthood

“…This finding was expected as the age range across all participants was 40 years. This was also consistent with prior neuroimaging studies that described an effect of aging on both brain structure and function in populations over age 50 (Betzel et al, 2014;Chan et al, 2014;Damoiseaux, 2017;Dima et al, 2020;Frangou et al, 2020;Luis et al, 2015;Luo et al, 2020b;Varangis et al, 2019a). The overall negative impact of age on each network largely confirms a reduction of functional cohesiveness of the major brain networks, particularly those supporting higher-order cognitive functions (Betzel et al, 2014;Damoiseaux et al, 2008;He et al, 2013;Mowinckel et al, 2012;Yaple et al, 2019).…”

Components of the Language-Ready Brain

“…Tellingly, when the auditory memory is overloaded (hence alpha rhythm enhancement is further employed), acoustic degradation affects processing, because of the noncanonical ellipsis of alpha suppression . This is also consistent with studies reporting an increased activation of the cerebellum in high-load tasks, suggesting a prominent role of the cerebellum in working memory processing (Kirschen et al, 2010;Stoodley et al, 2012;Luis et al, 2015).…”

Modafinil-Induced Changes in Functional Connectivity in the Cortex and Cerebellum of Healthy Elderly Subjects

“…Upon brain aging, cognitive deficiency can result from failure of inhibitory processes and the dysfunctional interplay between the WM and the attentional systems (Luis et al, 2015). This dysfunction can result in an overall reduced activity of filtering relevant information while increasing the production of noise overflow (Luis et al, 2015).…”

“…This dysfunction can result in an overall reduced activity of filtering relevant information while increasing the production of noise overflow (Luis et al, 2015). A similar deficit in cognitive control has been found to occur in mild cognitive impairment (MCI) or early-stage dementia patients.…”