Poster C44, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
Compensation or restoration: Optimizing tDCS-enhanced visual working memory in older adults
Hector Arciniega1, Filiz Gözenman2, Marian Berryhill1; 1University of Nevada, Reno, 2Yaşar University
Working memory (WM) permits maintenance of information over brief delays and is an essential executive function. Unfortunately, WM is subject to show age-related decline. Some evidence supports the use of transcranial direct current stimulation (tDCS) to improve visual WM. A gap in knowledge is an understanding of the mechanism characterizing these tDCS linked effects. Here, we tested two competing possibilities in older adults using different tDCS montages. In older adults, greater bilateral frontal activation is associated with cognitive task performance and is interpreted as compensation. If tDCS facilitates compensation, we predicted we would see superior WM performance after bilateral frontal tDCS. In contrast, if restoration of a more youthful pattern of right lateralized brain activity is superior, the unilateral frontoparietal tDCS would be better. We tested these predictions in healthy older adults (60-75 years). As our previous findings showed that WM capacity predicts differential responses to a tDCS protocol, we included an independent measure of WM capacity. Participants completed 3 sessions of 20 minutes of 2 mA anodal tDCS including bilateral frontal, right frontoparietal, and sham. During stimulation participants performed a visual long-term memory (LTM) control task and visual WM task. The results demonstrated no effect on the LTM task, and a greater benefit for the WM task when participants received the right unilateral stimulation, consistent with the prediction of restoration. This pattern was clearest in older adults with low WM capacity, suggesting tDCS-linked cognitive benefits might be optimized when returning to a more youthful pattern of brain activity.
Topic Area: EXECUTIVE PROCESSES: Working memory