Targeted dream incubation at sleep onset can influence later dream content in REM sleep: a pilot study.

Targeted dream incubation (TDI) is a highly effective method for eliciting hypnagogic dreams related to specific topics through the presentation of verbal prompts and serial awakenings at sleep onset. In this pilot study, we tested whether TDI at sleep onset can effectively direct dream content in subsequent rapid eye movement (REM) sleep. We allowed participants a daytime nap opportunity following TDI at sleep onset. Serial awakenings were performed both at sleep onset and after entry into REM sleep. Our primary objective was to assess whether the TDI protocol during the sleep onset period would continue to affect dream content in REM sleep, producing dreams of the target content ("tree") in the first REM awakening. Our second objective was to assess incorporation when participants received additional TDI prompts following REM awakenings. All 11 participants successfully incubated the target theme at sleep onset, and eight subsequently obtained REM sleep. Four of these participants (50%) incorporated the target theme into their first REM dream, and five incorporated the target theme in subsequent REM dreams (63%). Results provide preliminary evidence that TDI may impact dreams in REM sleep. This method of engineering dreams across sleep stages may be useful for understanding how dream generation and function may be continuous or different across sleep stages.