The Effect of Pre-Frontal tDCS on Sleep Propensity During an Afternoon Nap: RCT

Recent studies have demonstrated that there are cortical direct current (DC) changes that accompany sleep onset and transitions between sleep states in a stereotyped manner. In these studies it was determined that negative potential shifts occurred prior to and at the transition from wakefulness to sleep and at transitions between Rapid Eye Movement sleep (REM) sleep, and Non-Rapid Eye Movement (NREM) sleep. In a subset of experiments it was demonstrated that the same DC potential shifts occur during the transition from wake to sleep in an afternoon nap. The recorded DC potential shifts occurred predominantly in the pre-frontal cortex (F3, F4), with spread into central areas. No current literature exists that explores whether tDCS could be used to modulate cortical activity prior to sleep, resulting in either increased or decreased sleep propensity.

The application of focal, non-invasive brain stimulation has already led to novel and effective treatments for neuropsychiatric disease with minimal side effects (Most well studied in depression and repetitive Transcranial Magnetic Stimulation or, rTMS). Should the application of tDCS modulate sleep propensity it would represent a novel study paradigm with the potential to lead to a completely novel treatment for sleep disturbance. With this small pilot study, we propose taking the first step in exploring the utility of tDCS in modulating sleep propensity. We propose to recruit 15 healthy non-treatment seeking participants from the community and expose them to three total nap conditions in a randomized counter balanced fashion, with 10 minutes of either, Anodal, Cathodal, or Sham tDCS stimulation occurring prior to each nap opportunity.