%0 Journal Article %T The Modulation of Error Processing in the Medial Frontal Cortex by Transcranial Direct Current Stimulation %A Lisa Bella£¿che %A Manish Asthana %A Ann-Christine Ehlis %A Thomas Polak %A Martin J. Herrmann %J Neuroscience Journal %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/187692 %X Background. In order to prevent future errors, we constantly control our behavior for discrepancies between the expected (i.e., intended) and the real action outcome and continuously adjust our behavior accordingly. Neurophysiological correlates of this action-monitoring process can be studied with event-related potentials (error-related negativity (ERN) and error positivity (Pe)) originating from the medial prefrontal cortex (mPFC). Patients with neuropsychiatric diseases often show performance monitoring dysfunctions potentially caused by pathological changes of cortical excitability; therefore, a modulation of the underlying neuronal activity might be a valuable therapeutic tool. One technique which allows us to explore cortical modulation of neural networks is transcranial direct current stimulation (tDCS). Therefore, we tested the effect of medial-prefrontal tDCS on error-monitoring potentials in 48 healthy subjects randomly assigned to anodal, cathodal, or sham stimulation. Results. We found that cathodal stimulation attenuated Pe amplitudes compared to both anodal and sham stimulation, but no effect for the ERN. Conclusions. Our results indicate that cathodal tDCS over the mPFC results in an attenuated cortical excitability leading to decreased Pe amplitudes. We therefore conclude that tDCS has a neuromodulatory effect on error-monitoring systems suggesting a future approach to modify the sensitivity of corresponding neural networks in patients with action-monitoring deficits. 1. Introduction Performance monitoring is a major executive function, which allows for an online adaptation of behavior according to internal goals and standards and includes the process of error monitoring [1]. In order to accomplish goal-oriented behavior and prevent performance errors, we constantly control the outcome of our actions in order to detect a discrepancy between the expected (i.e., intended) and the real action-outcome, and continuously adjust our behavior accordingly. On the neurophysiological level, erroneous actions are accompanied by a frontocentral negativity (termed error negativity (Ne) or error-related negativity (ERN)) and a corresponding centroparietal positivity (error-positivity, Pe [2]). The ERN typically occurs within the first 100£¿ms after an erroneous response, while the Pe occurs within 200¨C450£¿ms after an incorrect response. Previous studies have shown that the medial frontal cortex (MFC) plays a key role in action monitoring [3]. The premotor/supplementary motor area (Brodman area 6) and caudal anterior cingulate cortex (ACC) have been %U http://www.hindawi.com/journals/neuroscience/2013/187692/