The first semi-multiple-systematic study of sleep and memory was conducted in 1924 by Jenkins and Dallenbach, for the purpose of testing Hermann Ebbinghaus' memory decay theory.[1] Their results showed that memory retention was much better after a period of sleep opposed to the same time interval spent awake. It wasn't until 1953 when sleep was delineated into rapid eye movement sleep and non-rapid eye movement sleep that studies focusing on the effect of specific sleep stages on memory were conducted.[1] As behavioural characteristics of the effects of sleep and memory are becoming increasingly more understood and supported, researchers are turning to the weakly understood neural basis of sleep and memory.[4]