http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2644330/
Retroactive Interference
Retroactive interference is the opposite of proactive interference. It is when a new memory gets in the way of remembering an older memory. This could happen if you were taking a final for a class and you are unable to remember the information from the beginning of this class, but you can remember the things you learned more recently