Editing Creativity (section)

==== REM sleep ====
Creativity involves the forming of associative elements into new combinations that are useful or meet some requirement. Sleep aids this process.<ref>{{cite journal |last1=Wagner |first1=U. |last2=Gais |first2=S. |last3=Haider |first3=H. |last4=Verleger |first4=R. |last5=Born |first5=J. |year=2004 |title=Sleep inspires insight |journal=Nature |volume=427 |issue=6972 |pages=352–55 |bibcode=2004Natur.427..352W |doi=10.1038/nature02223 |pmid=14737168 |s2cid=4405704}}</ref><ref>{{cite journal |last1=Cai |first1=Denise J. |last2=Mednick |first2=Sarnoff A. |last3=Harrison |first3=Elizabeth M. |last4=Kanady |first4=Jennifer C. |last5=Mednick |first5=Sara C. |title=REM, not incubation, improves creativity by priming associative networks |journal=Proceedings of the National Academy of Sciences |date=23 June 2009 |volume=106 |issue=25 |pages=10130–10134 |doi=10.1073/pnas.0900271106 |doi-access=free |pmid=19506253 |pmc=2700890 |bibcode=2009PNAS..10610130C }}</ref> [[Rapid eye movement sleep|REM]] rather than [[Non-rapid eye movement sleep|NREM sleep]] appears to be responsible.<ref name="Cai">{{cite journal |last1=Cai |first1=D.J. |last2=Mednick |first2=S.A. |last3=Harrison |first3=E.M. |last4=Kanady |first4=J.C. |last5=Mednick |first5=S.C. |year=2009 |title=REM, not incubation, improves creativity by priming associative networks |journal=Proc Natl Acad Sci USA |volume=106 |issue=25 |pages=10130–10134 |bibcode=2009PNAS..10610130C |doi=10.1073/pnas.0900271106 |pmc=2700890 |pmid=19506253 |doi-access=free}}</ref><ref>{{cite journal |last1=Walker |first1=M.P. |last2=Liston |first2=C. |last3=Hobson |first3=J.A. |last4=Stickgold |first4=R. |date=November 2002 |title=Cognitive flexibility across the sleep-wake cycle: REM-sleep enhancement of anagram problem solving |journal=Brain Res Cogn Brain Res |volume=14 |issue=3 |pages=317–24 |doi=10.1016/S0926-6410(02)00134-9 |pmid=12421655}}</ref> This may be due to changes in [[cholinergic]] and [[Norepinephrine|noradrenergic]] [[neuromodulation]] that occurs during REM sleep.<ref name="Cai" /> During this period of sleep, high levels of acetylcholine in the [[hippocampus]] suppress feedback from the hippocampus to the [[neocortex]], and lower levels of acetylcholine and norepinephrine in the neocortex encourage the spread of associational activity within neocortical areas without control from the hippocampus.<ref>{{cite journal |last=Hasselmo |first=M.E. |author-link=Michael Hasselmo |date=September 1999 |title=Neuromodulation: acetylcholine and memory consolidation |journal=Trends Cogn. Sci. |edition=Regul. |volume=3 |issue=9 |pages=351–359 |doi=10.1016/S1364-6613(99)01365-0 |pmid=10461198 |s2cid=14725160 |doi-access=free}}</ref> This is in contrast to waking consciousness, during which higher levels of norepinephrine and acetylcholine inhibit recurrent connections in the neocortex. REM sleep may aid creativity by allowing "neocortical structures to reorganize associative hierarchies, in which information from the hippocampus would be reinterpreted in relation to previous semantic representations or nodes."<ref name="Cai" />