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 phase. The prospect that well-known neurological aspects of REM do not themselves cause dreaming suggests the need to re-examine the neurobiology of dreaming "per se". Some researchers (Dement, Hobson, Jouvet, for example) tend to resist the idea of disconnecting dreaming from REM sleep. After waking from REM sleep, the mind seems “hyperassociative”—more receptive to semantic priming effects. People awakened from REM have performed better on tasks like anagrams and creative problem solving. Sleep aids the process by which creativity forms associative elements into new combinations that are useful or meet some requirement. This occurs in REM sleep rather than in