Working memory training in older adults: COMT Val158Met modulates the transfer of benefits in a virtual reality working memory task

Abstract

AbstractBackgroundIndividuals with the Val/Val homozygous variation of the catechol‐O‐methyltransferase (COMT) gene possess lower prefrontal dopaminergic levels than Met/‐carriers and show more pronounced age‐related cognitive impairment (Papenberg et al., 2015). The aim of this study was to examine the impact of the COMT genotype profile on the transfer of working memory (WM) training effect in older adults.Method60 older adults were randomly assigned to inhibition or updating WM training conditions which were provided over 12 half‐hour sessions (3 sessions per week). Their COMT genotype was determined from a salivary sample collected using an Oragene OG‐500 collection kit. Transfer was measured with untrained complex WM tasks: Alpha‐span, Reading‐span, and a Virtual Reality dual‐task (VR‐WM) involving the detection of a visual road sign and a concurrent verbal memory task. Testing was done weekly, but to limit the bias of regression to the mean with small samples, the first two and the last two assessments were averaged.ResultMixed model analyses showed better performance for COMT Met/‐carriers (n = 43) than Val/Val carriers (n = 11) in the Reading‐Span task and improved performance on the three transfer tasks. There was a COMT x Time interaction on the VR‐WM task. Post‐hoc analyses showed that only the Val/Val group improved their performance following training, allowing them to reach levels similar to that observed in the Met/‐carriers group.ConclusionOur results indicate an effect of the COMT status on WM performance and training transfer. The observed pattern is similar to that previously reported in younger adults (Colzato et al., 2014) and emphasizes the role of dopaminergic regulation in WM and WM malleability. Colzato, L. S., van den Wildenberg, W. P. M., & Hommel, B. (2014). Cognitive control and the COMT Val158Met polymorphism: Genetic modulation of videogame training and transfer to task‐switching efficiency. Psychological Research, 78(5), 670–678. https://doi.org/10.1007/s00426‐013‐0514‐8. Papenberg, G., Lindenberger, U., & Bäckman, L. (2015). Aging‐related magnification of genetic effects on cognitive and brain integrity. Trends in Cognitive Sciences. Elsevier Ltd. https://doi.org/10.1016/j.tics.2015.06.008.