Fig. 1.

Study design and experimental procedure. A) Timeline of the study showing the different time points. Behavioral and EEG variables were assessed at baseline (t0), evaluation (t1) and follow-up (t2). B) Sequence of an exemplary training session. Each session started with exercises targeting phonemic processing while gamma-tACS or sham-tACS was applied. Subsequently, during a short break of about 5 min, tACS-electrodes were removed and the participants completed a short questionnaire on their physical state and potential adverse events due to the electrical stimulation. Immediately after the break, participants performed the orthographic training.