Slow wave sleep (SWS) is essential for memory consolidation. When endogenous SWS is boosted by so-tES (0.75Hz) applied during sleep, overnight memory consolidation can be enhanced1. The present study explored whether so-tES (0.75Hz), applied immediately after learning and during wake, could enhance overnight memory consolidation and reduce the need for subsequent sleep, compared to an equivalent sham condition. Healthy young adults (18–35 years; n=14) completed cognitive and motor learning tasks in the evening before receiving 15 minutes of active or sham so-tES over task-related brain regions. Task performance was assessed during learning, after stimulation, and the next morning after sleep. Polysomnography was recorded in the sleep period following learning and brain stimulation. Participants completed both active and sham sessions, at least one week apart. The effects of so-tES on task performance, delta relative bandpower, and N3 duration (as a proportion of total sleep time) were estimated. Additional effects on several other characteristics of sleep were investigated in exploratory analyses. Preliminary results suggest that so-tES did not influence overnight memory consolidation, delta relative bandpower, or proportional N3 duration; however, exploratory analyses suggest that so-tES delayed sleep onset time and reduced total sleep time, without influencing sleep efficiency or intra-sleep awakening time. These results suggest that wakeful so-tES after learning may influence several characteristics of subsequent sleep; however, it does not influence overnight memory consolidation. A discussion and further analysis of these results will be presented.1Marshall et al., (2006) Nature 444(7119), 610–613.