Why we forget

The process underlying the creation of a memory is also very curious. As Dr. Palombo described, it involves 3 steps:. Both profs explained that the brain rewires itself whenever a new long-term memory gets made. To elaborate, Dr. Graf referred to this quote from the late Canadian neuroscientist Donald Hebb:.

Palombo said. The human brain occupies a fascinating evolutionary in-between of remembering and forgetting. In many cases, we keep only the gist of our experiences In fact, forgetting can be attributed to the presence of interfering memories and the fading of memories.

To paraphrase Dr. Palombo, gaining new information can interfere with your memories of old information, when the two are similar. One possibility is that the neural circuitry associated with the old memories gets rewired and harder to access and retrieve later—resulting in what we know as forgetting.

Graf explained what the curve means:. If you take notes throughout a class and look at them 24 hours later, I bet you that you won't have a clue what a huge portion of those notes are about. Palombo advised. In the past decade, researchers have begun to view forgetting as an important part of a whole. Memory, first and foremost, is there to serve an adaptive purpose. It endows us with knowledge about the world, and then updates that knowledge.

This article is part of Nature Outlook: The brain , an editorially independent supplement produced with the financial support of third parties. About this content. Berry, J. Neuron 74 , — PubMed Article Google Scholar. Migues, P. Akers, K. Science , — Schmitz, T. Nature Commun. Hulbert, J. Download references. Technology Feature 09 NOV Research Highlight 29 OCT Article 10 NOV News 04 NOV Research Highlight 03 NOV News 22 OCT Zhejiang University School of Medicine.

Francis Crick Institute. Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily. Advanced search. Skip to main content Thank you for visiting nature.

Credit: Sam Falconer. Research also suggests that the brain actively prunes memories that become unused, a process that is known as active forgetting. As memories accumulate, those that are not retrieved eventually become lost. Sometimes people forget due to a phenomenon known as interference. Some memories compete and interfere with other memories. When information is very similar to other information that was previously stored in memory, interference is more likely to occur.

There are two basic types of interference:. Sometimes the act of remembering something can lead to other things being forgotten. Research suggests that retrieving some information from memory can lead to retrieval-induced forgetting. This is particularly common when memory retrieval cues are very similar. While this causes forgetting, research also suggests that this type of forgetting can actually be adaptive.

By forgetting one memory in favor of another, it reduces the chance of interference happening again in the future. While interference can make it difficult to remember some things, there are things you can do to minimize its effects. Rehearsing new information is often the most effective approach.

By essentially overlearning new things, it is less likely that old information will compete with new. Sometimes, losing information has less to do with forgetting and more to do with the fact that it never made it into long-term memory in the first place. Encoding failures sometimes prevent information from entering long-term memory. In one classic experiment, researchers asked participants to identify the correct U. While people are familiar with this everyday object, they were surprisingly bad at being able to detect key details.

The reason for this is that only details necessary for distinguishing pennies from other coins were encoded into your long-term memory.

Identifying a penny does not require knowing the exact image or words found on the coin. Because this information is not really needed, most people never memorize it and commit it to memory.

Memories also tend to get simplified. While you might remember the overall gist of something, you are likely to forget many of the details. This is actually an adaptive function that allows you to efficiently store important things that you need to remember in the future. Sometimes we may actively work to forget memories, especially those of traumatic or disturbing events or experiences.

Painful memories can be upsetting and anxiety-provoking, so there are times we may desire to eliminate them. The two basic forms of motivated forgetting are suppression, which is a conscious form of forgetting, and repression, an unconscious form of forgetting.

However, the concept of repressed memories is not universally accepted by all psychologists. One of the problems with repressed memories is that it is difficult, if not impossible, to scientifically study whether or not a memory has been repressed.

Also note that mental activities such as rehearsal and remembering are important ways of strengthening memory, and memories of painful or traumatic life events are far less likely to be remembered, discussed, or rehearsed.

Forgetting painful memories and traumas may help people cope better. While these events might not be entirely forgotten, forgetting the vivid details can help blunt the difficult emotions that are attached to those memories and make them easier to live with. The most common reason why students forget is because the material is under learned. To remember something, it must first be learned, that is, stored in long term memory. To combat underlearning, repeatedly recite or quiz yourself on your textbook and lecture notes.

Moving information from short term memory toward long term memory is a process that takes time. That is why when material is reviewed once or twice, it is difficult to remember for quizzes and exams.