Recent evidence suggests that memories can be reactivated during sleep through the application of auditory and olfactory cues initially associated with learning, eventually leading to enhanced memory retrieval. Our project aims at better understanding the mechanisms subtending within-sleep memory reactivation, especially in the field of emotional memories. In parallel, transcranial Direct Current Stimulation (tDCS) has proven efficient to improve memory consolidation. Therefore, we wish to investigate whether tDCS applied during sleep can benefit memory reactivation. To this end, tDCS will be applied both in Non-Rapid EYE Movement (NREM) sleep and in Rapid Eye Movement (REM) sleep.