Multiparameter Optimized tES for Memory in Aging

With an aging population worldwide, it is critical to develop effective interventions promoting healthy cognitive aging. Transcranial electrical stimulation (tES) is a promising but not fully realized noninvasive brain stimulation approach that could improve memory. This study investigates the behavioral and electrocortical effects of personalized tES in aging to determine whether whether optimal dosing, electrode placements, and waveforms elicit stronger responses.

With an aging population worldwide, it is critical to develop effective interventions promoting healthy cognitive aging. A key component of healthy cognition is intact working memory, an executive neural process holding information temporarily. With increasing age, working memory capacity decreases and is associated with a loss of independence, thus incentivizing the need to retain a healthy working memory capacity. In addition to facilitating healthy aging, developing a method that improves working memory could help those diagnosed with mild cognitive impairment (MCI) and Alzheimer's Disease (AD), which is currently is the 6th leading cause of death in the US and has an annual economic burden of $305 billion. A potential approach to improve working memory is transcranial electrical stimulation (tES), a noninvasive brain stimulation method using scalp electrodes to deliver low electrical currents of 2 milliamps (mA) over the cortical target. While some prior studies have shown that prefrontal tES can improve working memory in older adults, there are small meta-analytic effect sizes and no FDA-approved indications to date. These mixed results could be due to applying one-size-fits-all and suboptimal tES parameters. In this study, the investigators will test the effects of personalized parameters, including dosing, electrode positioning, and waveforms compared to standard tES and placebo.