Even though we use it all day and night, we are usually not aware of our memory’s processes until they fail. Yet remembering and forgetting are crucial aspects of 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, instruction and creativity.
The Basics of Forgetting What We Learned
- Forgetting is the inability to recall or recognize information that we think is stored 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 your knowledge 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. This is one aspect that causes us to forget.
- 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 (recall).
- Cognitive psychologists think 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. Read more about prior knowledge and schemas.
- Many instances of forgetting may happen because retrieval cues that aide the recall process are not connecting to the appropriate memory, 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 consolidation doesn’t occur, the memories are less stable.
Interference May Impede Remembering
- 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 What Causes Us to Forget
- 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 often remember its meaning.
Benefits 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. According to Scott A. Small, “The ability to forget helps us prioritize, think better, make decisions, and be more creative. Normal forgetting, in balance with memory, gives us the mental flexibility to grasp abstract concepts from a morass of stored information, allowing us to see the forest through the trees.” See Why Forgetting is Good for Your Memory. For more on how forgetting is beneficial to creative thinking, see Forgetting as a Consequence and Enabler of Creative Thinking.
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.
Connie Malamed says
I’m sorry Beatriz but the original article was written a few years ago. I’m kind of surprised I don’t have citations in there, as I usually do, so I’m not sure where I got that. You might be able to find the info you’re looking for from Ruth Clark’s books and perhaps from the book Make It Stick.
thanks for the interesting article. Regarding the statement:
“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).”
Do you have some studies that discuss this? I am trying to get empirical evidence of the convenience of learning videos vs reading.
Connie Malamed says
That’s a great topic, but I haven’t seen (or looked) for research on that. A long time ago I vaguely remember reading that if you are woken up in the middle of a dream, you’re more likely to remember it. Also, writing your dreams in a journal the moment you wake up can help you remember as one might forget during the day. I don’t know if any of that is research based.
Parya Tavakoli-Tehrani says
Great article. I wonder if there is any research similar to this about remembering dreams. Could you let me know if you know any resources?
Connie Malamed says
Thank you for your informative comment, Stephanie.
Stephanie Richie says
Thanks for providing such a thought provoking post.
Things to remember about forgetting! One of the courses I teach is English Composition, and students always ask; why do I need to remember this? And more times than often, those same students perform poorly on testing. Learning the material is not enough alone to recall information when needed; being able to make a correlation and connection to the material is beneficial.
Presently, in my ID Program, Learning Theories and Instruction class, we are dealing with how the brain works, how we learn, and how we process information. Remembering is a vital part of the learning process and forgetting is in my opinion equally vital. Forgetting is so much a part of our daily routines that we ‘forget’ that we’ve forgotten. Our text points out much of the key factors you presented on interference and the decay of the long or short term memory. “…synapses (junctions between neurons) can deteriorate with lack of use in the same way muscles do with nonuse.” (Ormrod, 2009)
I’ve challenged my students to make meaningful connections with new material they are learning so that the information can be recalled in an efficient manner. And, yes, I did give 30 minute lecture on how the use of English Composition is intertwined with basically everything we do in our lives.
Ormrod, J., Schunk, D., & Gredler, M. (2009). Learning Theories and Instruction (Laureate Custom Edition). New York: Pearson.
The brain doesn’t actually understand ‘dont forget X’ – you’re telling it ‘not to do’ and ‘do it’ simultaneously. As in most good ‘brain’ books.
Lorena Bull, RD says
In my IDT program we are presently studying Learning Theory and your blog entry on “Forgetting” provides an excellent, useful summary of the information. It seems that there are many causes of both memory formation and retention. If only we could make a conscious decision for specific bits of information to be encoded into memory, at will! You mention that, “Some instances of forgetting are probably caused by not processing information in the first place.” I suppose this is what occurs in a sleep-deprived brain. The topic of the effects of sleep-deprivation on cognition is an area of research that I find interesting and can relate to personally, as can many of my classmates and colleagues, for sure. I would like to share some information on sleep deprivation that I encountered this week as I studied for my course. In one study, researchers (Florian, et al, 2011) used two methods to examine the role of increased levels of adenosine as a suspected cause of cognitive deficits that occur with sleep deprivation. The thought was that if the increased level of adenosine as a result of sleep deprivation was the cause of cognitive deficit, then cognitive deficit should be absent when the production of adenosine by glial cells is prevented, and also when the uptake of adenosine is blocked at the adenosine receptors of the hippocampus. One approach used mice that were genetically engineered so that their glial cells were unable to produce adenosine. A second approach involved the introduction of a drug that blocked an adenosine receptor in the hippocampus via a pump that was placed into the brains of non-genetically engineered mice. Researchers discovered that in both approaches, sleep-deprived mice performed as well as non-sleep deprived mice.
Interestingly, researchers have also confirmed what many bleary-eyed, coffee-chugging people have believed, that chronic caffeine consumption works in preventing sleep-deprivation-induced cognitive deficits, explaining that caffeine is an adenosine antagonist, meaning that it blocks the effects of adenosine (Alhaider, et al, 2010).
I would be interested in any information you or your readers have to share regarding sleep deprivation. I personally suffer from chronic partial sleep deprivation as a result of life circumstances, rather than from any organic condition or disease process, and while I do drink moderate amounts of iced tea and diet cola on a daily basis, I do not feel that the cognitive deficit is adequately ameliorated. And drinking massive amounts of caffeine is not recommended anyway because it causes negative side-effects. Hopefully, my life circumstances will improve, allowing me more time for sleep!
Alhaider, I. A., Aleisa, A. M., Tran, T. T., & Alkadhi, K. A. (2010). Caffeine prevents sleep loss-induced deficits in long-term potentiation and related signaling molecules in the dentate gyrus. European Journal of Neuroscience, 31(8), 1368-1376. doi: 10.1111/j.1460-9568.2010.07175.x.
Florian, C., Vecsey, C. G., Halassa, M. M., Haydon, P. G., & Abel, T. (2011). Astrocyte-derived adenosine and a1 receptor activity contribute to sleep loss-induced deficits in hippocampal synaptic plasticity and memory in mice. Journal of Neuroscience, 31(19), 6956. doi: 10.1523/JNEUROSCI.5761-10.2011
Connie Malamed says
I think it’s simply unknown — up for debate — as to whether someone literally “unlearns” or whether it’s all interference. On a physical level, you can imagine neurons losing their connections and getting new ones (perhaps this is interference) or getting atrophied through lack of use … but this hasn’t been proven. As to forgetting on purpose, that usually refers to our personal story memories — episodic memory. They say it’s hard to do. It makes me wonder how hypnotism works from a cognitive perspective. Interesting discussion.
Connie Malamed says
Sorry. I wouldn’t know how to begin.
Brian Dusablon says
We had a lengthy discussion about “unlearning” at Up To All of Us this year. I’ll try to find the image of our brainstorming/discussion notes, but it was an interesting conversation. Can one truly forget on purpose? Can we unlearn something, or do we simply replace it with new information or use that previous knowledge as a stepping stone or reference point?
Maybe something in Brain Rules would clarify?
Thanks for the post. I hope it stirs up some more conversation.
nasser hosseini says
Please explain how to teach Reading efficiently to the students.
Connie Malamed says
That book sounds interesting and so does your memoir writing class. I’m guessing that it refers to episodic memories, our memories of experiences and events. Although my article relates more to memory for learning facts and concepts, perhaps we create episodic memories around learning too. Nice to hear from you.
Connie, you publish the most interesting stuff. I found this post particularly interesting because of its application to memoir writing (which is something I pursue and also teach). There is an interesting book on this topic as it applies to memoir: Unreliable Truth, by Maureen Murdoch. Thanks for this very helpful post that I can apply to both writing and teaching.
Connie Malamed says
I’m sorry to hear that you’re having trouble with the models because of their similarities. I’m sure it’s very frustrating. I’d ask the instructor to help you clarify the differences and to give you examples of each model in action. Or perhaps you can write up the examples and that this will help you discriminate between them. Then try making a matrix with categories for each row and each column would be a different model. Then I’d fill in the matrix and see what’s common and what is different. This, along with your examples, could serve as your study guide.
Tracy P says
A very interesting article. I have problems with recall generally but at the moment I am having a few difficulties doing an essay on models (of translation theorists) even though I have gone over them again and again. I think your point about it being difficult to memorise information that is similar may well be the problem as the models all seem to be saying basically the same thing with just a few variations. The fast pace of the course is in my opinion part of the problem because we don’t have time to learn one model in detail before going on to the next.
Connie Malamed says
Thanks for catching the error, Sue. I think I know what you mean in your comment … not sure. Please explain more if you have time.
Sue J says
(typo: learner’s should be learners at that last line.)
A huge issue for me is not addressing stuff that’s “similar” or gets filed as such anyway. I’m thinking math and the trouble people have remembering that no, four to the third power is not twelve…