title: Does transcranial direct current stimulation enhance cognitive and motor functions in the ageing brain? A systematic review and meta- analysis.
abstract: The use of transcranial direct current stimulation (tDCS) to enhance cognitive and motor functions has enjoyed a massive increase in popularity. Modifying neuroplasticity via non-invasive cortical stimulation has enormous potential to slow or even reverse declines in functions associated with ageing. The current meta-analysis evaluated the effects of tDCS on cognitive and motor performance in healthy older adults. Of the 81 studies identified, 25 qualified for inclusion. A random effects model meta-analysis revealed a significant overall standardized mean difference equal to 0.53 (SE=0.09; medium heterogeneity: I(2)=57.08%; and high fail-safe: N=448). Five analyses on moderator variables indicated significant tDCS beneficial effects: (a) on both cognitive and motor task performances, (b) across a wide-range of cognitive tasks, (c) on specific brain areas, (d) stimulation offline (before) or online (during) the cognitive and motor tasks. Although the meta-analysis revealed robust support for enhancing both cognitive and motor performance, we outline a number of caveats on the use of tDCS.
authors.affiliation: Human Motor Control Laboratory, University of Tasmania, Hobart, Tasmania, Australia; Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK. Electronic address: Jeff.Summers@utas.edu.au.
authors.forename: Jeffery J
authors.initials: JJ
authors.lastname: Summers
authors.affiliation: Motor Behavior Laboratory, Applied Physiology and Kinesiology Dept., University of Florida, Gainesville, FL, USA.
authors.forename: Nyeonju
authors.initials: N
authors.lastname: Kang
authors.affiliation: Motor Behavior Laboratory, Applied Physiology and Kinesiology Dept., University of Florida, Gainesville, FL, USA.
authors.forename: James H
authors.initials: JH
authors.lastname: Cauraugh
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D006801:Humans; D008568:Memory / Q000502:physiology; D009043:Motor Activity / Q000502:physiology*; D065908:Transcranial Direct Current Stimulation / Q000379:methods*
keywords: Ageing; Anodal tDCS; Cognitive function; Meta-analysis; Motor function; Transcranial direct current stimulation (tDCS)