“Daytime Parahypnagogia” (DPH) refers to any extremely brief trancelike experience, occurring during wakefulness, that has hallucinatory or non-hallucinatory attributes accompanied by flashes of thought, insight and/or creativity. The experience is similar to what occurs sometimes on sleep onset, but it can occur at any time. The term was coined by Emile B. Gurstelle, Ph.D. in an article appearing in Medical Hypotheses in 2004.
Ref: Gurstelle,E.; de Oliveira J.(2004). Daytime parahypnagogia: a state of consciousness that occurs when we almost fall asleep. Medical Hypotheses, 62(2), 166-168.