FIGURE 1.

Timetable of the study. Day 1: entrance examination. Participants filled in questionnaires, underwent menstrual cycle screening and provided informed consent. Actigraphy and sleep diary were commenced and continued until day 7. Day 4: adaptation night. Overnight sleep in the laboratory, with polysomnography (PSG) and salivary samples taken pre‐ and post‐sleep. Day 6: Experimental night. Overnight sleep in the laboratory with polysomnography, word pair association tasks pre‐sleep (ENC = encoding), retrieval pre‐sleep (RET1) and salivary samples taken pre‐retrieval and pre‐sleep Retrieval post‐sleep (RET2) and salivary sample post‐sleep and post‐retrieval test were obtained. For statistical analyses, the progesterone values derived from the two samples collected before bedtime during the experimental night (saliva sample 3 and 4; framed in green) were taken