Enhancing Everyday Cognition in Healthy Older Adults via Non-Invasive Neurostimulation and Memory Training. An Integration of Neuroscience and Rehabilitation Science
AuthorStephens, Jaclyn Anne
AdvisorBerryhill, Marian E.
AltmetricsView Usage Statistics
Older adulthood is associated with decline in working memory (WM) and prospective memory (PM) performance. These declines can negatively impact everyday cognitive task ability (e.g. remembering to take medication;Woods et al., 2014), which subsequently affect quality of life. Cognitive training interventions are designed to restore cognitive abilities, but many fall short and show little transfer to untrained tasks (for review see: Karbach & Verhaeghen, 2014). To extend cognitive training we paired it with neurostimulation in healthy older adults to extend our previous positive findings (Jones, Stephens, Alam, Bikson, & Berryhill, 2015). This approach successfully elicited WM beyond training benefits in the group receiving WM training and higher intensity transcranial direct current stimulation (tDCS). This current study also tested for improvements in everyday cognition, explored optimal tDCS parameters, and the underlying tDCS mechanism. Over 5 consecutive days, we paired WM and PM training with parametric anodal tDCS dosage (Sham, 1mA, or 2mA) to the right prefrontal cortex (PFC) in healthy older adults (aged 55-85; N = 90). At follow-up a month later, there were significant improvements in everyday cognitive ability only in those who received 2mA of tDCS. FNIRS data revealed a significant reduction in bilateral PFC recruitment in the 2mA group potentially indicative of improved efficiency. Finally, tDCS may modify dopaminergic activity in PFC, and tDCS-based WM enhancement may be genotype-specific.