Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique (NIBS) able to induce transient alteration of the cortical excitability. Recent surveys have stimulated the DLPFC using non-invasive brain stimulation techniques and have shown selective modulation of behaviours related to executive control and attention. Whilst behavioural effects of administering tDCS to the DLPFC have been demonstrated, to date not many studies have combined tDCS with any brain imaging techniques and the neural patterns underlying these behavioural changes have not yet been explored in detail. For this reason, this study seeks to address these shortcomings using electroencephalography (EEG), by combining tDCS of the DLPFC with recording of electrical brain activity. For this purpose it has been used a typical task administered to investigate working memory ability, the so-called delayed-match-to-sample task. Results seem to show that anodal stimulation over left DLPFC as compared to sham stimulation, improves RT performance on mismatch trials where S1 is different from S2. Moreover, this improvement of integration process between the two stimuli mediated by the visual working memory (Zhang et al., 2008) with anodal stimulation, is associated with a stronger magnitude of both mismatch triggered negativity and lateralized readiness potential components.
Keywords: Dorsolateral prefrontal cortex (DLPFC), match-to-sample task, ERPs, mismatch triggered negativity, lateralized readiness potential, tDCS.