title: Longitudinal neurostimulation in older adults improves working memory.
abstract: An increasing concern affecting a growing aging population is working memory (WM) decline. Consequently, there is great interest in improving or stabilizing WM, which drives expanded use of brain training exercises. Such regimens generally result in temporary WM benefits to the trained tasks but minimal transfer of benefit to untrained tasks. Pairing training with neurostimulation may stabilize or improve WM performance by enhancing plasticity and strengthening WM-related cortical networks. We tested this possibility in healthy older adults. Participants received 10 sessions of sham (control) or active (anodal, 1.5 mA) tDCS to the right prefrontal, parietal, or prefrontal/parietal (alternating) cortices. After ten minutes of sham or active tDCS, participants performed verbal and visual WM training tasks. On the first, tenth, and follow-up sessions, participants performed transfer WM tasks including the spatial 2-back, Stroop, and digit span tasks. The results demonstrated that all groups benefited from WM training, as expected. However, at follow-up 1-month after training ended, only the participants in the active tDCS groups maintained significant improvement. Importantly, this pattern was observed for both trained and transfer tasks. These results demonstrate that tDCS-linked WM training can provide long-term benefits in maintaining cognitive training benefits and extending them to untrained tasks.
authors: Memory and Brain Laboratory, Department of Psychology, University of Nevada, Reno, Nevada, United States of America; Cognitive Neuropsychology Lab, Department of Neurology, Georgetown University Medical Center, Washington, District of Columbia, United States of America.
authors: Kevin T
authors: KT
authors: Jones
authors: Memory and Brain Laboratory, Department of Psychology, University of Nevada, Reno, Nevada, United States of America.
authors: Jaclyn A
authors: JA
authors: Stephens
authors: Department of Biomedical Engineering, The City College of New York, New York, New York, United States of America.
authors: Mahtab
authors: M
authors: Alam
authors: Department of Biomedical Engineering, The City College of New York, New York, New York, United States of America.
authors: Marom
authors: M
authors: Bikson
authors: Memory and Brain Laboratory, Department of Psychology, University of Nevada, Reno, Nevada, United States of America.
authors: Marian E
authors: ME
authors: Berryhill
mesh_terms: D000328:Adult; D000368:Aged; D002540:Cerebral Cortex / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000503:physiopathology* / Q000628:therapy*; D008570:Memory, Short-Term; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology*