Fig 1. Study design: A double-blind, randomized, crossover study.

Twenty-four participants were recruited and randomly assigned to receive either tDCS or sham stimulation during the first trial. After an interval of at least four weeks, the second trial was conducted. The order of the two stimulation conditions (i.e., tDCS or sham) was counterbalanced across participants. After delivering one of the two stimulus conditions, ASSRs were recorded using MEG. We excluded two participants from the statistical analysis because they met the exclusion criteria. ASSR, auditory steady-state response.