Slide Slam S4 Sandbox Series
The benefits of regular physical exercise training for brain structure and function in relation to tip-of-the-tongue states in healthy ageing
Foyzul Rahman1, Samuel J.E. Lucas1, Eunice G. Fernandes2, Allison Wetterlin2, Hilde Lohne-Seiler2, Sveinung Bernsten2, Sindre Fosstveit2, Linda Wheeldon2, Katrien Segaert1; 1University of Birmingham, UK., 2University of Agder, Norway.
Regular physical activity is protective against age-related decay of executive function, including working memory and inhibitory control (Weinstein et al., 2012). Further, studies have shown that longitudinal aerobic exercise training interventions in older adults is associated with greater total brain volume, in both grey and white matter regions (e.g., Colcombe et al., 2006). However, it is unclear whether these benefits extend beyond executive function. What is currently lacking is knowledge about the effects of exercise on language abilities in healthy ageing. Many language processes are isolated from, and independent of, other cognitive faculties. For example, word finding difficulties are not age-associated failures of long-term memory, as word knowledge increases with age, but the ability to successfully access the words’ phonological form decreases. Recently, we have demonstrated that while older adults generally experience more word finding difficulties relative to younger adults, fitter older adults experience fewer word finding difficulties than age-matched unfit older adults (Segaert et al., 2018). Building on this, for the first time in the literature, we will conduct a six-month, endurance-based exercise intervention where we will test linguistic and non-linguistic cognitive performance in exercising (treatment) and non-exercising (control) older adults, in addition to acquiring structural and functional brain data to investigate the neural changes underlying the benefits of exercise on language. To this end, pre- and post-intervention, we will collect executive function (e.g., processing speed, working memory, inhibition), language function (e.g., word finding or tip-of-the-tongue states [TOT]) and physical fitness/physical function (e.g., oxygen consumption, hand-grip strength) measures in healthy older adults. Collection of physical function data will allow us to quantify increases in fitness levels due to the intervention and map these alterations onto linguistic and non-linguistic performance. We will also acquire fMRI during a TOT task to highlight differential recruitment according to TOT vs. non-TOT states, between exercising and control participants. Additionally, we will acquire high-resolution T1 anatomical images to permit examination of grey matter density in key language areas (e.g., left insula) and conduct a perfusion sequence to obtain cerebral blood flow and volume. Potential changes in grey matter density and cerebral blood flow/volume will then be directly mapped onto the (predicted) behavioural benefits of improved physical fitness, afforded by the intervention. We will use a resting state sequence to utilise resting-state-fluctuation-amplitude to correct our fMRI data for variability in neurovascular coupling among our older participants. Overall, we aim to establish for the first time a causal relationship between physical exercise and ameliorated language decline in healthy ageing. The acquisition of neuroimaging will allow us to understand the neural consequences of increased physical fitness, first, as a standalone measure, but also as a key component in the relationship between increased physical fitness and the advantages it confers in linguistic and non-linguistic aptitudes.