non-rem sleep helps memory also

In an article from sciencenews.com, neuroscientists from Harvard University found that drinking about a specific task helps recall, not just the act of sleeping itself. This effect is more dramatic than just simply thinking about the task while still awake or just taking a break from the activity. This study was mainly aimed at NREM, or non-rapid eye movement sleep. This interests me because previously I thought that only REM sleep was beneficial to memory formation. The study subjects were asked to remember the path to a certain spot in a maze and then to recall this path later in the day after various activities. The participants that took the short nap and dreamed about the maze, or other aspects of what was going on at that time, recalled the event better than the control group that did not take the nap and even better than those that did sleep but did not dream of the maze. The scientists speculate that the increased memory formation is still due to activity in the Hippocampus, as was originally thought with REM sleep. Also, the subjects that did dream about the event did poorly in recalling their way around the maze before their naps. This is interesting because it suggests that the information was still in their brains, but they were unable to recall this information until it was processed by the hippocampus during sleep. This is interesting to me as with most college students, I usually do not obtain the recommended eight hours of sleep a night, but naps could still help me increase my memory recall without falling into REM sleep.



Stephen Infanger

source: http://www.sciencenews.org/view/generic/id/58525/title/Dream_a_little_dream_of_recall

Why Sleepyheads Forget

Neuroscientists at the University of Pennsylvania have found one way that lack of sleep can alter the process of learning. It has been known for some time now that lack of sleep can affect episodic memory retention, but this study has found one specific cause of this detrimental effect of sleep deprivation – an increase in enzyme that breaks apart cAMP in the hippocampus. This enzyme is a phosphodiesterase called PDE4A5, and it was found to be elevated up to 40% in sleep deprived mice.

To verify their hypothesis that this increased enzyme production caused the lack of memory retention in sleep deprivation, the scientists administered a drug called rolipram to slow phospodiesterase production in the mice’s hippocampus. According to their results, sleep deprived mice that were given rolipram were capable of remembering as well as mice that were allowed to rest normally. The repercussions of this study and those like it could be helpful to college students who wish to have all-night study sessions and still retain the information for the test on the next day and possibly even the final, or this could usher in new memory drugs that help the brain process information better and retain knowledge longer.

Source:
http://sciencenow.sciencemag.org/cgi/content/full/2009/1021/1

Stephen Infanger
VTPP 434-502