Targeted dream incubation (TDI) at sleep onset can influence dream content in subsequent REM sleep, according to a pilot study published June 24 in Frontiers in Sleep, suggesting that the hypnagogic period and REM sleep may share a continuous dream generation system.
The study, led by Adam Haar Horowitz of MIT Media Lab and Beth Israel Deaconess Medical Center, tested whether verbal prompts delivered during the sleep-onset period could steer dream content not only in the brief hypnagogic dreams that immediately follow, but also in later REM sleep dreams.
What they found. All 11 participants successfully incubated the target theme (“tree”) at sleep onset. Eight of them subsequently entered REM sleep. Four of those eight (50%) incorporated the target theme into their first REM dream, and five (63%) did so in subsequent REM dreams. The protocol used serial awakenings and verbal prompts at sleep onset, followed by a daytime nap, with additional awakenings after REM entry.
Why it matters. The hypnagogic period, the transitional state between wake and sleep, has typically been studied separately from REM sleep dreaming. These results provide preliminary evidence that the two states share a continuous dream generation system, where suggestions made during one sleep stage can carry over into another. This has implications for understanding dream function, for therapeutic dream modification (for example, in nightmare disorder), and for the emerging field of dream engineering.
Limits. This is a pilot study with only 11 participants and 8 who reached REM sleep. The results need replication in a larger sample. The target theme (“tree”) was simple and concrete; whether complex narrative content can be similarly incubated across sleep stages remains unknown.
Bottom line. Targeted dream incubation at sleep onset can influence later REM dream content, suggesting shared dream generation mechanisms across these sleep stages.
Source. Haar Horowitz A, Konkoly KR, Carr M, Stickgold R, Maes P. “Targeted dream incubation at sleep onset can influence later dream content in REM sleep: a pilot study.” Frontiers in Sleep. 2026 Jun 24;5:1812535. doi:10.3389/frsle.2026.1812535. PMID: 42422173.