Non-rapid eye movement sleep 3D maze. Participants were then trained in the maze for 4 hours and later, during the various sleep cycles of nonREM sleep, REM sleep and wakefulness, they were scanned twelve times using a PET scan during the night. The PET scan demonstrated a higher blood flow in the hippocampus during SWS/non-REM sleep due to the training from the previous day while the control group exhibited no increased blood flow and they had not received the training the prior day. The brain activity during sleep, according to this study, would show the events of the previous day do make a difference.
Rapid eye movement sleep humor, the liquid between cornea and iris, was stagnant if not stirred. Among the supportive evidences, he calculated that if aqueous humor was stagnant, oxygen from iris had to reach cornea by diffusion through aqueous humor, which was not sufficient. According to the theory, when the animal is awake, eye movement (or cool environmental temperature) enables the aqueous humor to circulate. When the animal is sleeping, REM provides the much-needed stir to aqueous humor. This theory is consistent with the observation that fetuses, as well as eye-sealed newborn animals, spend much time in REM sleep, and that during a normal