The effect of computerized cognitive training and exercise on white matter integrity: a secondary analysis of a randomized controlled trial

Abstract

AbstractBackgroundAs a consequence of aging, the structure of the brain can be negatively impacted, and consequently, cognitive function. Although aerobic exercise and computerized cognitive training (CCT) are promising lifestyle interventions to prevent or delay cognitive decline, the underlying mechanisms of the effect of CCT, with or without exercise, on cognitive function remain poorly understood. Diffusion tensor imaging (DTI) is a neuroimaging technique for detecting changes in white matter (WM) tissue. Common DTI metrics such as fractional anisotropy (FA) can be summarized as a measure of overall WM integrity. The aim of this analysis was to explore the effect of CCT, with or without exercise, on WM integrity in healthy older adults.MethodsThis sub‐analysis included 65 community‐dwelling older adults aged 65‐85 years. Participants were enrolled in an 8‐week proof‐of‐concept randomized controlled trial and were assigned to either: 1) Group‐based CTT (Fit Brains; FBT; n = 19) 3x/week for 1hr plus 3x/week home‐based training; 2) Group‐based CCT preceded by exercise (ExFBT; n = 22) 3x/week for 1hr plus 3x/week home‐based training or; 3) Group‐based balanced‐and‐toned (BAT; n = 24) classes 3x/week for 1hr (control). DTI scans were acquired at baseline and at trial completion. Analysis of covariance (ANCOVA) evaluated treatment effects on FA at trial completion controlling for baseline age, MoCA, BMI, and FA. We conducted planned contrasts of FBT vs. BAT and ExFBT vs. BAT. In addition, we included an exploratory comparison between ExFBT vs. FBT.ResultsWe found significant group differences in fornix and superior longitudinal fasciculus (SLF) FA at trial completion. Planned contrasts revealed significantly greater fornix FA in BAT vs. FBT (mean difference = 0.015, 95%CI = 0.002‐0.029). Also, fornix FA was significantly greater in ExFBT vs. FBT (mean difference = 0.017, 95%CI = 0.003‐0.031). In addition, SLF FA was significantly greater in ExFBT vs. FBT (mean difference = 0.008, 95%CI = 0.001‐0.014) at trial completion.ConclusionThese findings suggest CCT alone may be detrimental to WM integrity, potentially due to its sedentary nature.