Editing Long-term memory (section)

===Sleep===
Some theories consider [[sleep]] to be an important factor in establishing well-organized long-term memories. ''(See also [[sleep and learning]].)'' Sleep plays a key function in the consolidation of new memories.<ref name="Ruch, S. 2012">{{cite journal | last1 = Ruch | first1 = S. | last2 = Markes | first2 = O. | last3 = Duss | first3 = B. S. | last4 = Oppliger | first4 = D. Reber | last5 = Koenig | first5 = T. | last6 = Mathis | first6 = J. | last7 = Roth | first7 = C. | last8 = Henke | first8 = K. | year = 2012 | title = Sleep stage II contributes to the consolidation of declarative memories | journal = Neuropsychologia | volume = 50 | issue = 10| pages = 2389–2396 | doi=10.1016/j.neuropsychologia.2012.06.008| pmid = 22750121 | s2cid = 18771496 }}</ref>

According to Tarnow's theory, long-term memories are stored in [[dream]] format (reminiscent of Penfield & Rasmussen's findings that electrical excitations of the cortex give rise to experiences similar to dreams). During waking life an executive function interprets LTM consistent with reality checking {{Harv|Tarnow|2003}}. It is further proposed in the theory that the information stored in memory, no matter how it was learned, can affect performance on a particular task without the subject being aware that this memory is being used. Newly acquired declarative memory traces are believed to be reactivated during NonREM sleep to promote their hippocampo-neocortical transfer for long-term storage.<ref>{{cite journal|last1=Bergmann|first1=T. O.|last2=Molle|first2=M.|last3=Diedrichs|first3=J.|last4=Born|first4=J.|last5=Siebner|first5=H. R.|title=Newly acquired declarative memory traces are believed to be reactivated during NonREM sleep to promote their hippocampo-neocortical transfer for long-term storage|journal=NeuroImage|date=1 February 2012|volume=59|issue=3|pages=2733–2742|doi=10.1016/j.neuroimage.2011.10.036|pmid=22037418|s2cid=15223346}}</ref> Specifically, new declarative memories are better remembered if recall follows Stage II non-rapid eye movement sleep. The reactivation of memories during sleep can lead to lasting synaptic changes within certain neural networks. It is the high spindle activity, low oscillation activity, and delta wave activity during NREM sleep that helps to contribute to declarative memory consolidation. In learning before sleep, spindles are redistributed to neuronally active up-states within slow oscillations during NREM sleep.<ref name="Ruch, S. 2012"/> Sleep spindles are thought to induce synaptic changes and thereby contribute to memory consolidation during sleep. Here, we examined the role of sleep in the object-place recognition task, a task closely comparable to tasks typically applied for testing human declarative memory: It is a one-trial task, hippocampus-dependent, not stressful and can be repeated within the same animal.<ref>{{cite journal|last1=Binder|first1=S.|last2=Baier|first2=P.|last3=Mölle|first3=M.|last4=Inostroza|first4=M.|last5=Born|first5=J|last6=Marshall|first6=L.|title=Sleep enhances memory consolidation in the hippocampus-dependent object-place recognition task in rats.|journal=Neurobiology of Learning and Memory |date=February 2012|volume=2|issue=97|pages=213–219|doi=10.1016/j.nlm.2011.12.004|pmid=22207008|s2cid=366647}}</ref> Sleep deprivation reduces vigilance or arousal levels, affecting the efficiency of certain cognitive functions such as learning and memory.<ref>{{cite journal|last1=Martella|first1=D.|last2=Plaza|first2=V.|last3=Estévez|first3=A. F.|last4=Castillo|first4=A.|last5=Fuentes|first5=L. J.|title=Minimizing sleep deprivation effects in healthy adults by differential outcomes|journal=Acta Psychologica|year=2012|volume=139|issue=2|pages=391–396|doi=10.1016/j.actpsy.2011.12.013|pmid=22321451}}</ref>

The theory that sleep benefits memory retention is not a new idea. It has been around since [[Forgetting curve|Ebbinghaus's]] experiment on forgetting in 1885. More recently studies have been done by Payne and colleagues and Holtz and colleagues.<ref name="Holz, J. 2012">{{cite journal | last1 = Holz | first1 = J. | last2 = Piosczyk | first2 = H. | last3 = Landnann | first3 = N. | last4 = Feige | first4 = B. | last5 = Spiegelhalden | first5 = K. | last6 = Riemann | first6 = D. | last7 = Nissen | first7 = C. | last8 = Voderholzer | first8 = V. | year = 2012 | title = The timing of learning before night-time sleep differential affects declarative and procedural long-term memory consolidation in adolescents | journal = PLOS ONE | volume = 7 | issue = 7| pages = 1–10 | doi=10.1371/journal.pone.0040963| bibcode = 2012PLoSO...740963H | pmid=22808287 | pmc=3395672| doi-access = free }}</ref> In Payne and colleague's<ref name="Payne2012">{{cite journal | last1 = Payne | first1 = D. J. | last2 = Tucker | first2 = A. M. | last3 = Ellenbogen | first3 = M. J. | last4 = Wamsley | first4 = J. E. | last5 = Walker | first5 = P. M. | last6 = Schacter | first6 = L. D. | last7 = Stickglod | first7 = R. | year = 2012 | title = Memory for semantically related and unrelated declarative information: the benefit of sleep, the cost of wake | journal = PLOS ONE | volume = 7 | issue = 3| pages = 1–8 | doi = 10.1371/journal.pone.0033079 | bibcode = 2012PLoSO...733079P | pmid=22457736 | pmc=3310860| doi-access = free }}</ref> experiment participants were randomly selected and split into two groups. Both groups were given semantically related or unrelated word pairs, but one group was given the information at 9 A.M. and the other group received theirs at 9 P.M. Participants were then tested on the word pairs at one of three intervals 30 minutes, 12 hours, or 24 hours later. It was found that participants who had a period of sleep between the learning and testing sessions did better on the memory tests. This information is similar to other results found by previous experiments by Jenkins and Dallenbach (1924). It has also been found that many domains of declarative memory are affected by sleep such as emotional memory, semantic memory, and direct encoding.<ref name="Payne2012"/>

Holtz<ref name="Holz, J. 2012"/> found that not only does sleep affect consolidation of declarative memories, but also procedural memories. In this experiment, fifty adolescent participants were taught either word pairs (which represents declarative memory) and a finger tapping task (procedural memory) at one of two different times of day. What they found was that the procedural finger tapping task was best encoded and remembered directly before sleep, but the declarative word pairs task was better remembered and encoded if learned at 3 in the afternoon.<ref name="Holz, J. 2012"/>