Even though it’s used all day and night, we are usually not aware of our memory’s processes until they fail. Yet remembering and forgetting are crucial phenomena underlying learning. In learning design, it’s important to know what causes us to forget. Here are some key facts about the forgetting process that relate to learning and instruction.
- Forgetting is the inability to recall or recognize information that we think should reside in long-term memory. Recall refers to reproducing or reconstructing a memory without a specific external cue; recognition refers to identifying something you learned previously based on external cues.
- There is a debate as to what causes forgetting. Some researchers think that old memories slowly decay from lack of use (or disassociate from the network) over time. The prominent theory at this time, however, is that we forget due to interference or a failure of having the proper retrieval cues.
- Recalling a memory changes it. The act of reconstructing a memory makes it relatively stronger than other memories and may modify its contents.
- Memories can fail at any time during the three stages of processing: encoding (registering in long-term memory), consolidation (deep processing and stabilization), or during retrieval.
- It is thought that long-term memories are stored as parts of schema or cognitive structures. One reason we may modify memories is to keep them consistent with our schema. This may be the reason people are known to give inaccurate accounts of events.
What Causes Us to Forget
- Some instances of forgetting may result from not processing information in the first place. If we don’t pay attention to information or an event, then we fail to register it.
- Even when we attend to information, a long-term memory will not form if the information lacks a connection to anything else we know. With no connection, we don’t understand it.
- Many instances of forgetting may happen because retrieval cues are not connecting to the appropriate schema, even though the information is stored. Memories that are part of a strong network will be easier to retrieve.
- Memory consolidation involves deep processing and associating information in a meaningful way with a network of learned information. When memories are not consolidated, they are less stable.
Types of Interference
- Interference is a critical factor in forgetting. Retrieving a memory probably involves pattern completion. In this theory, the cue (such as a question) activates the associated schema to complete the pattern. Interference of one type or another can lead to failure of retrieving the correct information.
- Retroactive interference (RI) occurs when newly learned information impedes the recall of something you previously learned. For example, if you are learning Spanish, you may not recall how to pronounce a word in French. The rules of Spanish pronunciation are interfering with this.
- We don’t yet know whether retroactive interference is due to the interference of competing stimuli or whether a person is actually unlearning the forgotten material.
- Proactive interference occurs when past memories inhibit one’s ability to retain new information. For example, you may have trouble remembering a new password because you used your previous password for years.
- The more similar new information is to previous knowledge, the more likely it is that interference will occur. The converse is also true.
Learning and Forgetting
- Forgetting happens most rapidly soon after learning something and then tapers off with the passage of time.
- People will first forget content that does not make sense to them.
- Most people are more likely to forget what they hear than what they read. This is probably because reading is a more focused activity than listening (and perhaps for other reasons as well),
- Although we may forget the exact words of something we just read, we can remember the meaning of it.
Advantages of Forgetting
- The fact that people forget unremarkable events is probably a matter of survival. Forgetting trivia helps us to function throughout the day. The standard example to demonstrate this advantage is that if you remembered every parking spot you’ve ever had, how would you remember where your car is at the moment?
- Fairly recent research showed that forgetting may make more brain power available for other tasks. In one study, the cortex of subjects who did not have competing memories when asked to recall information did less work than those who had competing memories. See You Must Remember This.
What can learning specialists conclude from the science of forgetting?
- To form a persistent memory, a person must pay attention to the information, process it deeply and connect it in a meaningful way with existing knowledge.
- A person’s preexisting knowledge may compete with newly acquired information. In this case, allow the person time to discriminate between the two types of similar content.
- Practicing information retrieval can facilitate retention because reconstructing memories alters them and makes them “stronger.”
- Don’t expect learners to remember trivial information. They will most likely forget it after a test.
Also see Explanations for Forgetting.