Transcranial direct current stimulation eliminates the own-age bias as indexed by the face inversion effect for own- versus other-age faces

We investigate individuals' reduced ability to recognize faces of other ages, a phenomenon known as the Own-Age Bias (OAB). This study utilized a double-blind, between-subjects design in which anodal tDCS (10 minutes duration, 1.5 mA intensity, targeting the Fp3 location) was applied to disrupt the face inversion effect (FIE), which reflects higher recognition performance for upright compared to upside-down faces. Young adults participated in an old/new recognition task, where upright and inverted 'own-age' faces (19-30 years) and 'other-age' faces (older, 69-80 years) were presented. In the sham/control condition (n = 24), we observed a robust OAB, indicated by a significantly larger FIE for own-age faces compared to other-age faces. Importantly, in the anodal tDCS condition (n = 24), the FIE for own-age faces was significantly reduced compared to the sham condition, effectively eliminating the cross-age interaction index of the OAB. We interpret our results through a perceptual expertise-based account of the OAB.