Anodal transcranial direct current stimulation of right temporoparietal area inhibits self-recognition

Self-other discrimination is a crucial mechanism for social cognition. Neuroimaging and neurostimulation research points to the involvement of the right temporoparietal region in a variety of self-other discrimination tasks. While repetitive transcranial magnetic stimulation over the right temporoparietal area has been shown to disrupt self-other discrimination in face-recognition tasks, no research has investigated the effect of increasing cortical excitability in this region on self-other face discrimination. Here we used transcranial direct current stimulation (tDCS) to investigate changes in self-other discrimination with a video morphing task in which the participant’s face morphed into, or out of, a familiar other’s face. The task was performed before and after 20 minutes of tDCS targeting the right temporoparietal area (Anodal, Cathodal or Sham stimulation). Differences in task performance following stimulation were taken to indicate a change in self-other discrimination. Following Anodal stimulation only, there was a significant increase in the amount of self-face needed to distinguish between self and other. The findings are discussed in relation to the control of self and other representations, and domain general theories of social-cognition.