"Post‐training stimulation of the right dorsolateral prefrontal cortex impairs working memory training performance"

Postdoctoral Fellow Jacky Au (pictured right) is first author, along with UCI Alumnus Austin Moon and Associate Professor Susanne Jaeggi, of an article in the Journal of Neuroscience Research on the effects of transcranial direct current stimulation (tDCS) to enhance cognitive training.

​The title of the article is “Post‐training stimulation of the right dorsolateral prefrontal cortex impairs working memory training performance.”
 
Co-authors are Professor Benjamin Katz, Virginia Tech; Sheebani Talati, University of Michigan, Ann Arbor; Dr. Tessa R. Abagis, University of Michigan, Ann Arbor; and Professor John Jonides University of Michigan, Ann Arbor.
 
Au is a postdoctoral scholar in Jaeggi’s Working Memory and Plasticity (WMP) lab. He received his Ph.D. in 2019 from the Cognitive Sciences Department at UCI. In support of his doctoral studies, Au was awarded a National Science Foundation Graduate Research Fellowship. 

Au’s interests surround the nature and enhancement of brain plasticity, including the use of transcranial direct current stimulation (tDCS) and computerized training of targeted cognitive processes such as working memory. His current focus combines his two interests by evaluating the enhancement of cognitive training benefits using tDCS. He recently was accepted in the TL-1 scholars training program at the UC Irvine Institute for Clinical and Translational Science (ICTS).

Moon graduated from the University of California, Irvine in 2017 with a B.S. in Cognitive Sciences and a B.A. in Education Sciences. As an undergraduate he served as lab manager for Jaeggi’s WPM lab. Currently, Moon is a graduate student at UC Riverside pursuing a degree in neuroscience and a member of UCR’s CALLA (Cognitive Agility Across the Lifespan) lab.  His research interest includes visual search, attention, and perceptual learning using computational modeling, EEG, and deep learning techniques.
 
Jaeggi researches training and transfer, individual differences in working memory capacity and executive control, as well as the nature of working memory limitations across the lifespan. In addition to directing UCI's Working Memory and Plasticity Lab, Jaeggi is a fellow of the Center for the Neurobiology of Learning and Memory and holds a courtesy appointment in the Department of Cognitive Sciences in UCI's School of Social Sciences.
 
Abstract
 
Research investigating transcranial direct current stimulation (tDCS) to enhance cognitive training augments both our understanding of its long‐term effects on cognitive plasticity as well as potential applications to strengthen cognitive interventions. Previous work has demonstrated enhancement of working memory training while applying concurrent tDCS to the dorsolateral prefrontal cortex (DLPFC). However, the optimal stimulation parameters are still unknown. For example, the timing of tDCS delivery has been shown to be an influential variable that can interact with task learning. In the present study, we used tDCS to target the right DLPFC while participants trained on a visuospatial working memory task. We sought to compare the relative efficacy of online stimulation delivered during training to offline stimulation delivered either immediately before or afterwards. We were unable to replicate previously demonstrated benefits of online stimulation; however, we did find evidence that offline stimulation delivered after training can actually be detrimental to training performance relative to sham. We interpret our results in light of evidence suggesting a role of the right DLPFC in promoting memory interference, and conclude that while tDCS may be a promising tool to influence the results of cognitive training, more research and an abundance of caution are needed before fully endorsing its use for cognitive enhancement. This work suggests that effects can vary substantially in magnitude and direction between studies, and may be heavily dependent on a variety of intervention protocol parameters such as the timing and location of stimulation delivery, about which our understanding is still nascent.
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