Working Memory Training Effects on White Matter Integrity in Young and Older Adults

Abstract

ObjectivesWorking memory is essential for daily life skills like reading comprehension, reasoning, and problem-solving. Healthy aging of the brain goes along with working memory decline that can affect older people’s independence in everyday life. Interventions in the form of cognitive training are a promising tool for delaying age-related working memory decline, yet the underlying structural plasticity of white matter is hardly studied.MethodsWe conducted a longitudinal diffusion tensor imaging study to investigate the effects of an intensive four-week adaptive working memory training on white matter integrity quantified by global and tract-wise mean diffusivity. We compared diffusivity measures of fiber tracts that are associated with working memory of 32 young and 20 older participants that were randomly assigned to a working memory training group or an active control group.ResultsThe behavioral analysis showed an increase in working memory performance after the four-week adaptive working memory training. The neuroanatomical analysis revealed a decrease in mean diffusivity in the working memory training group after the training intervention in the right inferior longitudinal fasciculus for the older adults. There was also a decrease in mean diffusivity in the working memory training group in the right superior longitudinal fasciculus for the older and young participants after the intervention.ConclusionThis study shows that older people can benefit from working memory training by improving their working memory performance that is also reflected in terms of improved white matter integrity in the superior longitudinal fasciculus and the inferior longitudinal fasciculus, where the first is an essential component of the frontoparietal network known to be essential in working memory.

Adaptive working memory training does not produce transfer effects in cognition and neuroimaging

“…While there has been no TBSS study on the effects of WM training, a few research groups have explored effects of this kind of training on white matter integrity using voxel-based morphometry or an ROI analysis [30][31][32][33]. They reported training associated-changes in frontal and parietal white matter tracts [33], corpus callosum [31], in regions of the dopaminergic system [32], and in the superior and inferior longitudinal fasciculus [30]. However, in line with our resting-state fMRI and FDG-PET results, we found no significant effects of WM training on white matter integrity.…”

“…However, neither of these studies used an active control group nor did their analyses cover the whole brain. Similarly, only a few studies have investigated changes in structural connectivity, that is, neural tracts, following WM training [30][31][32][33]. Results indicated training-associated changes in frontal and parietal white matter tracts [30,33] or the corpus callosum [31].…”

“…Similarly, only a few studies have investigated changes in structural connectivity, that is, neural tracts, following WM training [30][31][32][33]. Results indicated training-associated changes in frontal and parietal white matter tracts [30,33] or the corpus callosum [31]. Takeuchi et al [32] reported that WM training increased the mean diffusivity in regions of the dopaminergic system.…”

Tract-Based Spatial Statistics Analysis of Diffusion Tensor Imaging in Older Adults After the PICMOR Intervention Program: A Pilot Study

“…To prevent or slow age-related changes in cognitive function and white matter, various cognitive intervention/training paradigms have been developed (Wassenaar et al, 2019). Previous studies have attempted to elucidate intervention/training-induced white matter changes using DTI (Lovden et al, 2012;Chapman et al, 2015;Nozawa et al, 2015;Antonenko et al, 2016;Fissler et al, 2017;Dziemian et al, 2021). However, the use of comprehensive DTI metrics to assess intervention/training effects on white matter fiber health in older adults remains limited (Lovden et al, 2010;Engvig et al, 2012;Strenziok et al, 2014;Lampit et al, 2015;Cao et al, 2016;de Lange et al, 2016de Lange et al, , 2017Youn et al, 2019).…”

Memory-Enhancing Effect of 8-Week Consumption of the Quercetin-Enriched Culinary Herbs-Derived Functional Ingredients: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

“…Memory, especially working memory, or the ability to maintain and manipulate information over a period [ 3 ], is necessary for daily life skills such as reading, comprehension, and problem-solving [ 4 ]. This capacity declines as age advances [ 5 ].…”