acquired, these associations remain intact in the memory. People keep acquiring numerous such associations and each of these rests independently without any mutual conflict. However, interference comes about at a time of retrieval when these various sets of associations compete with each other for retrieval. This interference process will become clearer with a simple exercise.
Request your friend to learn two separate lists of nonsense syllables (list A and list B) one after the other and after a while ask her/him to recall the nonsense syllables of list A. If while trying to recall the items of list A, s/he recalls some of the items of list B, it is because of the association formed while learning list B are interfering with the earlier association which were formed while learning list A. There are atleast two kinds of interferences that may result in forgetting. Interference can be proactive (forward moving) which means what you have learnt earlier interferes with etc.) and then measured the number of trials he took to relearn the same list at varying time intervals.
He observed that the course of forgetting follows a certain pattern which you can see in Figure . . As the figure indicates, the rate of forgetting is maximum in the first nine hours, particularly during the first hour. After that the rate slows down and not much is forgotten even after many days.
Although Ebbinghaus’s experiments constituted initial explorations and were not very sophisticated yet they have influenced memory research in many important ways. It is now upheld, almost unanimously, that there is always a sharp drop in memory and thereafter the decline is very gradual. Let us now examine the main theories, which have been advanced to explain forgetting. Forgetting due to Trace Decay Trace decay (also called disuse theory) is the earliest theory of forgetting.
The assumption here is that memory leads to modification in the central nervous system, which is akin to physical changes in the brain called memory traces . When these memory traces are not used for a long time, they simply fade away and become unavailable.