Effect of Sleep on MemoryThis article is taken from the Journal of Experimental Psychology and was written about an experiment performed by psychologist Bruce R. Ekstrand, of the University of Colorado. He experienced the effects sleep has on memory after learning a particular piece of knowledge, in this case a certain list of twelve three-letter words. There were several ways in which Ekstrand discovered whether or not sleep facilitated memory. Of the entire group of people he experimented on, some of them were given nothing more than a simple list to memorize, some were given a proactive interference list, and some were given a retroactive interference list. For his main measurement method, he used a 3x2 factorial plot. In this factorial there were the three types of interference learning he used: retroactive, proactive and without interference. The two parts of the factorial were the sleep levels obtained by those who were tested: eight hours of sleep or nothing. Participants were supposed to learn these certain lists and associations....