title: Individual Differences and Long-term Consequences of tDCS-augmented Cognitive Training.
abstract: A great deal of interest surrounds the use of transcranial direct current stimulation (tDCS) to augment cognitive training. However, effects are inconsistent across studies, and meta-analytic evidence is mixed, especially for healthy, young adults. One major source of this inconsistency is individual differences among the participants, but these differences are rarely examined in the context of combined training/stimulation studies. In addition, it is unclear how long the effects of stimulation last, even in successful interventions. Some studies make use of follow-up assessments, but very few have measured performance more than a few months after an intervention. Here, we utilized data from a previous study of tDCS and cognitive training [Au, J., Katz, B., Buschkuehl, M., Bunarjo, K., Senger, T., Zabel, C., et al. Enhancing working memory training with transcranial direct current stimulation. Journal of Cognitive Neuroscience, 28, 1419-1432, 2016] in which participants trained on a working memory task over 7 days while receiving active or sham tDCS. A new, longer-term follow-up to assess later performance was conducted, and additional participants were added so that the sham condition was better powered. We assessed baseline cognitive ability, gender, training site, and motivation level and found significant interactions between both baseline ability and motivation with condition (active or sham) in models predicting training gain. In addition, the improvements in the active condition versus sham condition appear to be stable even as long as a year after the original intervention.
authors.affiliation: University of Michigan.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Katz
authors.affiliation: University of California, Irvine.|MIND Research Institute, Irvine, CA.
authors.forename: Jacky
authors.initials: J
authors.lastname: Au
authors.affiliation: MIND Research Institute, Irvine, CA.
authors.forename: Martin
authors.initials: M
authors.lastname: Buschkuehl
authors.affiliation: University of Michigan.
authors.forename: Tessa
authors.initials: T
authors.lastname: Abagis
authors.affiliation: University of Michigan.
authors.forename: Chelsea
authors.initials: C
authors.lastname: Zabel
authors.affiliation: University of California, Irvine.
authors.forename: Susanne M
authors.initials: SM
authors.lastname: Jaeggi
authors.affiliation: University of Michigan.
authors.forename: John
authors.initials: J
authors.lastname: Jonides
mesh_terms: D000293:Adolescent; D000328:Adult; D003071:Cognition / Q000502:physiology*; D015928:Cognitive Behavioral Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D007206:Individuality; D008137:Longitudinal Studies; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology; D009042:Motivation / Q000502:physiology; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000502:physiology*; D012044:Regression Analysis; D065908:Transcranial Direct Current Stimulation / Q000379:methods*; D055815:Young Adult