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Longitudinal neurostimulation in older adults improves working memory.

Jones KT, Stephens JA, Alam M, Bikson M, Berryhill ME - PLoS ONE (2015)

Bottom Line: Such regimens generally result in temporary WM benefits to the trained tasks but minimal transfer of benefit to untrained tasks.The results demonstrated that all groups benefited from WM training, as expected.These results demonstrate that tDCS-linked WM training can provide long-term benefits in maintaining cognitive training benefits and extending them to untrained tasks.

View Article: PubMed Central - PubMed

Affiliation: 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.

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.

No MeSH data available.


Combined benefit indices (follow-up compared to session 1) for the five trained and three transfer tasks for each stimulation group (active, sham).The active tDCS groups were collapsed across site because there was no significant difference between them. Error bars represent standard error of the mean.
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pone.0121904.g003: Combined benefit indices (follow-up compared to session 1) for the five trained and three transfer tasks for each stimulation group (active, sham).The active tDCS groups were collapsed across site because there was no significant difference between them. Error bars represent standard error of the mean.

Mentions: However, at follow-up, after a month of no contact, a different pattern emerged. Repeating the analysis described above, using benefit indices from baseline incorporating follow-up performance, there was again a main effect of benefit index (F1, 70 = 34.54, MSE = 2.06, p <.001, partial η2 = .33), such that the trained benefit index was significantly greater than the transfer benefit index across both groups. Importantly, there was also a significant main effect of tDCS group (F1, 70 = 7.32, MSE = .25, p <.01, partial η2 = 0.10) such that the active tDCS group showed significantly greater performance across trained and transfer tasks; see Fig 3. This was driven largely by improvements on the more difficult spatial 2-back and OSpan tasks (see below). There was no group x benefit index interaction (F1, 70 = .10, MSE = .01, p = .75, partial η2 <.01). These findings demonstrate that active tDCS to frontoparietal sites sustained practice gains for trained WM tasks and enhanced transfer task performance. In other words, all groups showed practice related improvement, but only active tDCS sustained these gains.


Longitudinal neurostimulation in older adults improves working memory.

Jones KT, Stephens JA, Alam M, Bikson M, Berryhill ME - PLoS ONE (2015)

Combined benefit indices (follow-up compared to session 1) for the five trained and three transfer tasks for each stimulation group (active, sham).The active tDCS groups were collapsed across site because there was no significant difference between them. Error bars represent standard error of the mean.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4388845&req=5

pone.0121904.g003: Combined benefit indices (follow-up compared to session 1) for the five trained and three transfer tasks for each stimulation group (active, sham).The active tDCS groups were collapsed across site because there was no significant difference between them. Error bars represent standard error of the mean.
Mentions: However, at follow-up, after a month of no contact, a different pattern emerged. Repeating the analysis described above, using benefit indices from baseline incorporating follow-up performance, there was again a main effect of benefit index (F1, 70 = 34.54, MSE = 2.06, p <.001, partial η2 = .33), such that the trained benefit index was significantly greater than the transfer benefit index across both groups. Importantly, there was also a significant main effect of tDCS group (F1, 70 = 7.32, MSE = .25, p <.01, partial η2 = 0.10) such that the active tDCS group showed significantly greater performance across trained and transfer tasks; see Fig 3. This was driven largely by improvements on the more difficult spatial 2-back and OSpan tasks (see below). There was no group x benefit index interaction (F1, 70 = .10, MSE = .01, p = .75, partial η2 <.01). These findings demonstrate that active tDCS to frontoparietal sites sustained practice gains for trained WM tasks and enhanced transfer task performance. In other words, all groups showed practice related improvement, but only active tDCS sustained these gains.

Bottom Line: Such regimens generally result in temporary WM benefits to the trained tasks but minimal transfer of benefit to untrained tasks.The results demonstrated that all groups benefited from WM training, as expected.These results demonstrate that tDCS-linked WM training can provide long-term benefits in maintaining cognitive training benefits and extending them to untrained tasks.

View Article: PubMed Central - PubMed

Affiliation: 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.

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.

No MeSH data available.