Neural correlates of working memory training: Evidence for plasticity in older adults
Alexandru D. Iordan,
Katherine A. Cooke,
Kyle D. Moored,
Benjamin Katz,
Martin Buschkuehl,
Susanne M. Jaeggi,
Thad A. Polk,
Scott J. Peltier,
John Jonides,
Patricia A. Reuter-Lorenz
Affiliations
Alexandru D. Iordan
Department of Psychology, University of Michigan, 530 Church St, Ann Arbor, MI, 48109, United States; Corresponding author. 530 Church St, Ann Arbor, MI, 48109, United States.
Katherine A. Cooke
Department of Psychology, University of Michigan, 530 Church St, Ann Arbor, MI, 48109, United States
Kyle D. Moored
Department of Mental Health, Bloomberg School of Public Health, Johns Hopkins University, 615 N Wolfe St, Baltimore, MD, 21205, United States
Benjamin Katz
Department of Human Development and Family Science, Virginia Tech, 295 W Campus Dr, Blacksburg, VA, 24061, United States
Martin Buschkuehl
MIND Research Institute, 5281 California Ave., Suite 300, Irvine, CA, 92617, United States
Susanne M. Jaeggi
School of Education, University of California, Irvine, 3200 Education Bldg, Irvine, CA, 92697, United States
Thad A. Polk
Department of Psychology, University of Michigan, 530 Church St, Ann Arbor, MI, 48109, United States
Scott J. Peltier
Functional MRI Laboratory, Department of Biomedical Engineering, University of Michigan, 2360 Bonisteel Blvd, Ann Arbor, MI, 48109, United States
John Jonides
Department of Psychology, University of Michigan, 530 Church St, Ann Arbor, MI, 48109, United States
Patricia A. Reuter-Lorenz
Department of Psychology, University of Michigan, 530 Church St, Ann Arbor, MI, 48109, United States; Corresponding author.
Brain activity typically increases with increasing working memory (WM) load, regardless of age, before reaching an apparent ceiling. However, older adults exhibit greater brain activity and reach ceiling at lower loads than younger adults, possibly reflecting compensation at lower loads and dysfunction at higher loads. We hypothesized that WM training would bolster neural efficiency, such that the activation peak would shift towards higher memory loads after training. Pre-training, older adults showed greater recruitment of the WM network than younger adults across all loads, with decline at the highest load. Ten days of adaptive training on a verbal WM task improved performance and led to greater brain responsiveness at higher loads for both groups. For older adults the activation peak shifted rightward towards higher loads. Finally, training increased task-related functional connectivity in older adults, both within the WM network and between this task-positive network and the task-negative/default-mode network. These results provide new evidence for functional plasticity with training in older adults and identify a potential signature of improvement at the neural level.
