This is encouraging because a previous study showed minimal effect on dreaming using tDCS.
In both experiments a significantly greater number of imagery reports were found on awakening after tDCs (cathodal–frontal, anodal–parietal), compared to the blank control conditions. However, in Experiment 2 the frequency of imagery reports from the tDCs (cathodal–frontal, anodal–parietal) was not significantly different from the other two tDC conditions, suggesting a non-specific effect of tDCs. Overall, it was concluded that tDCs (cathodal–frontal, anodal–parietal) increased the frequency of dream reports with visual imagery, possibly via a general arousing effect and/or recreating specific cortical neural activity involved in dreaming.
via Induction of visual dream reports after transcranial direct current stimulation (tDCs) during Stage 2 sleep – JAKOBSON – 2012 – Journal of Sleep Research – Wiley Online Library. Full pdf.
This is one of the applications of tDCS I’ve been waiting to hear about. I was hoping tDCS might help facilitate an active dreaming state or even lucid dreaming.
In summary, using two different methodologies it appears that tDCS had no effect on the presence of dream reports with visual imagery or measures of dream quality. However, this may be due to methodological limitations of these stud- ies, as the delivery methods employed allowed only low levels of tDCS to be delivered without waking participants. Improvements allowing higher levels of stimulation during sleep and stimulation of other cortical regions could poten- tially provide more definitive conclusions regarding the ef- fectiveness of tDCS on dream imagery reported from REM sleep.
Investigation of visual dream reports after tran- scranial direct current stimulation (tDCS) during REM sleep (pdf)