Modified: 2014-01-02
An early theory of forgetting was the decay theory. It held that older memories decayed or rotted over time. The data, however, do not support decay theory.
Another unresolved theoretical issue is whether forgetting really takes place. Retrieval-failure theories state that memories never disappear; they just cannot be found. True-forgetting theories state that some memories do disappear and that no amount of searching will ever find them.
Interference theories state that two kinds of interference are always operating. Proactive interference works from the past to the present. Retroactive interference works from the present back to the past. The graphics proactive and retroactive show how one would experimentally measure both kinds of interference. Most memory items are subject to both kinds of interference. Think of taking two final exams on the same day and studying for them the night before. Studying for the first exam will interfere proactively with your studying for the second exam. Then, studying for the second exam will interfere retroactively with your memory from studying for the first exam.
