"in the classic experiment in which two groups of students studied lists of words with one group staying awake before the testing and the other group sleeping, the students who slept after studying the list remembered more because they experienced less"

In this group, the one that is held to the minimum would be: Retroactive interference
Retroactive interference is a phenomenon that happen when a new information interfere with someone's ability to recall the previous information that we have.
Retroactive interference commonly happened if we tried to put out a load of information within a short period of time