Long-Term Enhancement of Brain Function and Cognition Using Cognitive Training and Brain Stimulation

Abstract

Noninvasive brain stimulation has shown considerable promise for enhancing cognitive functions by the long-term manipulation of neuroplasticity [1Reis J. Schambra H.M. Cohen L.G. Buch E.R. Fritsch B. Zarahn E. Celnik P.A. Krakauer J.W. Noninvasive cortical stimulation enhances motor skill acquisition over multiple days through an effect on consolidation.Proc. Natl. Acad. Sci. USA. 2009; 106: 1590-1595Crossref PubMed Scopus (974) Google Scholar, 2Cohen Kadosh R. Soskic S. Iuculano T. Kanai R. Walsh V. Modulating neuronal activity produces specific and long-lasting changes in numerical competence.Curr. Biol. 2010; 20: 2016-2020Abstract Full Text Full Text PDF PubMed Scopus (255) Google Scholar, 3Dockery C.A. Hueckel-Weng R. Birbaumer N. Plewnia C. Enhancement of planning ability by transcranial direct current stimulation.J. Neurosci. 2009; 29: 7271-7277Crossref PubMed Scopus (288) Google Scholar]. However, the observation of such improvements has been focused at the behavioral level, and enhancements largely restricted to the performance of basic tasks. Here, we investigate whether transcranial random noise stimulation (TRNS) can improve learning and subsequent performance on complex arithmetic tasks. TRNS of the bilateral dorsolateral prefrontal cortex (DLPFC), a key area in arithmetic [4Zamarian L. Ischebeck A. Delazer M. Neuroscience of learning arithmetic—evidence from brain imaging studies.Neurosci. Biobehav. Rev. 2009; 33: 909-925Crossref PubMed Scopus (156) Google Scholar, 5Arsalidou M. Taylor M.J. Is 2+2=4? Meta-analyses of brain areas needed for numbers and calculations.Neuroimage. 2011; 54: 2382-2393Crossref PubMed Scopus (515) Google Scholar], was uniquely coupled with near-infrared spectroscopy (NIRS) to measure online hemodynamic responses within the prefrontal cortex. Five consecutive days of TRNS-accompanied cognitive training enhanced the speed of both calculation- and memory-recall-based arithmetic learning. These behavioral improvements were associated with defined hemodynamic responses consistent with more efficient neurovascular coupling within the left DLPFC. Testing 6 months after training revealed long-lasting behavioral and physiological modifications in the stimulated group relative to sham controls for trained and nontrained calculation material. These results demonstrate that, depending on the learning regime, TRNS can induce long-term enhancement of cognitive and brain functions. Such findings have significant implications for basic and translational neuroscience, highlighting TRNS as a viable approach to enhancing learning and high-level cognition by the long-term modulation of neuroplasticity.