Cathodal tDCS over the right prefrontal cortex and inhibitory control: Pinpointing an electrode montage to disrupt a domain-general system

Abstract

While many tDCS studies have focused on enhancing inhibitory control, only a few have employed tDCS to disrupt the neural activity of specific brain regions and gain understanding of their contribution to inhibitory control. This mini-review describes and discusses the results of studies that specifically applied cathodal tDCS over the right dorsolateral prefrontal cortex. The majority of these studies employed variants of experimental procedures that assessed the ability to inhibit either inappropriate motor responses or competing memories during selective retrieval. In both domains, action stopping and memory downregulation, neuroimaging research has shown that successful inhibitory control engages common areas within the right lateral prefrontal cortex. Strikingly, although a significant proportion of the reviewed studies reported behavioral effects that can be interpreted as a consequence of hindering inhibitory control, they have not been previously considered or discussed altogether despite its theoretical and methodological implications. This consistent disruptive effect challenges the common belief that cathodal tDCS is ineffective in modulating performance when applied to prefrontal regions. Additionally, the results provide causal evidence that supports the proposed role of the right lateral prefrontal cortex in a domain-general inhibitory system, particularly in relation to stopping actions and downregulating competing memories.