 Event Related Potentials ERP analyses ERPs will be analyzed using a step-wise procedure that permits the time-wise, multifactorial statistical assessment of 1 the dynamic changes of scalp-recorded electric field configuration and their temporal segmentation into quasi-stable functional micro-states indexing modulations of the configuration of intracranial generators, 2 global electric field power indexing modulation of response strength of the intracranial generators, 3 intracranial distributed linear electrical source estimations. These analyses will be conducted for each time frame of the whole ERP time-period; however, specific time windows are planned to be sensitive to the investigators factors according to meta-analyses and the investigators previous results: lexical selection is thought to occurs between 170 and 270 ms after picture presentation, so there will be a first time window until 200 ms, a second time window between 200 and 300 ms, and a later time window 300-450 ms corresponding to lexical-phonological encoding in previous studies. The main effect will be L1 and L2 patterns in term of amplitude, duration and sequences. Then, a second main effect will be the anodal tDCS sham tDCS effect in an early time window before the vocalization will start. The investigators will expect an interaction between language and stimulation, due to the fact that left DLPFC anodal-tDCS will modulate L2 more than 