We and others have previously shown that one can modulate arithmetic performance using transcranial direct current stimulation (tDCS; cf. Hauser et al., 2013; Rütsche et al., 2015). In this study, we investigated the effect of tDCS on arithmetic learning. Arithmetic learning is characterized by the transfer from effortful calculation of arithmetic problems to fast memory-based fact retrievals. This is known to be one of the crucial processes that are learnt in school. Here, we investigated whether 30 minutes of tDCS can change the learning curve of healthy subjects. We found that anodal stimulation over parietal areas improved learning whereas cathodal tDCS impaired the learning. Moreover, the cathodal effect lasted for at least 24 hours after the stimulation. This study thus shows that even short-term stimulation can induce lasting stimulation effects.
Grabner RH, Rütsche B, Ruff CC & Hauser TU (2015). Transcranial direct current stimulation of the posterior parietal cortex modulates arithmetic learning. Eur J Neurosci.