Neurocognitive mechanisms of numerical intervention studies: The case of brain stimulation

Numerical skills encompass a variety of cognitive processes and are crucial for performance in today's modern world but vary greatly between individuals. Several approaches of numerical cognition have been studied ranging from behavioral to neuroimaging studies. Transcranial electrical stimulation (tES) has become a promising tool to influence numerical cognition and is frequently used in clinical settings. The main aim of this chapter is to shed light onto current tES research as an intervention in this domain. We first provide a brief overview of the underlying neurocognitive mechanisms of basic and advanced mathematical skills, such as working memory, executive functions, and (non)symbolic number skills, since tES allows to intervene and further unravel the role of these mechanisms. In addition, we discuss the need for tES research to focus on the transfer of these skills to a similar numerical task to determine facilitation by means of neuroplasticity. Therefore we emphasize studies using tES as a numerical intervention and focus on transfer effects since these outcomes could contribute to implications for educational practice