Bridging cognition and action: executive functioning mediates the relationship between white matter fiber density and complex motor abilities in older adults

Abstract

Aging may be associated with motor decline that is attributed to deteriorating white matter microstructure of the corpus callosum (CC), among other brain-related factors. Similar to motor functioning, executive functioning (EF) typically declines during aging, with age-associated changes in EF likewise being linked to altered white matter connectivity in the CC. Given that both motor and executive functions rely on white matter connectivity via the CC, and that bimanual control is thought to rely on EF, the question arises whether EF can at least party account for the proposed link between CC-connectivity and motor control in older adults. To address this, diffusion magnetic resonance imaging data were obtained from 84 older adults. A fiber-specific approach was used to obtain fiber density (FD), fiber cross-section (FC), and a combination of both metrics in eight transcallosal white matter tracts. Motor control was assessed using a bimanual coordination task. EF was determined by a domain-general latent EF-factor extracted from multiple EF tasks, based on a comprehensive test battery. FD of transcallosal prefrontal fibers was associated with cognitive and motor performance. EF partly accounted for the relationship between FD of prefrontal transcallosal pathways and motor control. Our results underscore the multidimensional interrelations between callosal white matter connectivity (especially in prefrontal brain regions), EF across multiple domains, and motor control in the older population. They also highlight the importance of considering EF when investigating brain-motor behavior associations in older adults.

Neural Mechanisms of Neuro-Rehabilitation Using Transcranial Direct Current Stimulation (tDCS) over the Front-Polar Area

“…Tessitore et al (2012) reported that severity of freezing of gait was associated with a reduction of functional connectivity within the two cortical networks: executiveattention (PFC) and visual (right occipito-temporal gyrus) networks [36]. In addition, executive function, which is mainly supported by the dlPFC, is positively associated with hand dexterity [37][38][39]. These findings suggest that the target brain areas for PD treatment should include not only the cortico-basal ganglia motor circuits, but also cortical circuits such as the dlPFC.…”

Is an 8-Week Regimen of Nordic Walking Training Sufficient to Benefit Cognitive Performance in Healthy Older Adults? A Pilot Study

“…In particular, improving cognitive functions (attention, inhibition, visuospatial capacities, etc.) is important because they strongly determine behavioral adaptability in everyday life situations and complex movement tasks [ 2 , 3 , 4 , 5 ]. It is widely accepted that both endurance and muscular resistance training, when performed separately or in association, effectively counteract the effects of aging on cognitive capacities [ 6 , 7 , 8 , 9 ].…”

Effects of home-based manual dexterity training on cognitive function among older adults: a randomized controlled trial

“…Among the many deleterious effects of aging, deterioration of manual dexterity is one that can lead to difficulty in performing instrumental activities of daily living, such as writing, cooking, gardening, working on crafts, and opening a bottle [ 1 – 3 ]. These principal aging-associated changes are observed in both men and women, especially those older than 65 years [ 4 – 6 ].…”

“…Manual dexterity is related to not only executive function but also muscle strength [ 2 , 9 ]. Moreover, the performance of executive functions is related to the motor control performance (i.e., manual dexterity) of both hands, especially the non-dominant hand in older adults [ 3 , 10 , 11 ]. Manual dexterity is particularly important to ensure independent living of older adults owing to its association with the performance of instrumental activities of daily living [ 6 ].…”

“…Interestingly, an acute experimental study revealed that compared to the easier task (control, and trail-making test (TMT) part A), the difficult task (TMT part B) shows greater activation of the prefrontal cortex (PFC) in younger adults [ 18 ]. However, only a few intervention studies exist that confirmed the cognitive load of training in older adults through fNIRS and verified the effect of training [ 3 ].…”