Why We Forget
Lose something every day. Accept the fluster
of lost door keys, the hour badly spent.
The art of losing isn’t hard to master.
– “One Art” by Elizabeth Bishop
The excerpt above is from one of my favorite poems. It begins by talking about the little things that we forget each day. Then, it moves into a more tragic place: how we lose things that are important to us as time moves on. What is it that makes us forget?
To first understand how we forget things, it is important to know how the brain stores information. In Nelson Cowan’s article, “What are the differences between long-term, short-term , and working memory,” he describes all three.
Working memory is closely related to, and often confused with, short-term memory. According to Cowan, working memory allows us to solve simple math problems without using paper and ensures that we do not use the same ingredient twice while baking a cake. Working memory must access information from the long-term memory and relate it to the task at hand.
Short-term memory also holds information in a temporary state. It is very accessible but not detailed. The website The Human Memory explains that short-term memory can only hold about seven items for ten to fifteen seconds (the longest time the information can last is one minute). An example is translation work. The interpreter has to temporarily store information from one language while speaking in another.
Forgetting generally involves an inability to access information in the short or long-term memory. Psychologist World describes three reasons that we forget things placed in our short-term memory. The first is decay. If a person does not rehearse the information to transfer it from short-term to long-term memory, the idea fades. The second is displacement, which means that the memory has been replaced by another. Finally, there is interference. Interference happens when one is trying to remember things that are similar to previously held memories. This happens in two ways. The first is previous memories can make integrating the new information difficult (like when a person is trying to learn a word similar to one they already know), or, the new information may “distort” older memories.
According to WebMD, this interference is the reason that people can’t find their car keys or forget the reason they walked into the kitchen. To avoid interference, they quote Dr. Adam Gazzaley’s advice, which is to focus on what you are doing. “Mentally rehearse what you’re doing, and hold it in mind, until you’re finished with the task,” he says. He also suggests practicing. The brain is a muscle, and, if we challenge it, it will grow stronger. He suggests going to the grocery store without a list.
The third and final type of memory is long-term. Cowan describes long-term memory as a “vast store of knowledge” that holds a record of earlier events.
We may be unable to recall information in long-term memory for the same reasons we have problems with short-term memory: decay, displacement, and interference. One recent study, cited in Scientific American, explains another reason we may be unable to access information from the long-term memory. Dr. Timothy Brady from M.I.T. describes the importance of retrieval cues. According to Simply Psychology, retrieval cues provide the brain with a reminder that helps it access information. Retrieval cues can take the form of pictures, scents, audio cues (like songs), or simply revisiting the place where a memory was planted.
While forgetting things is inevitable, there are ways to limit our forgetting. Stay focused on a task while putting information into short-term memory. To make your long-term memory more reliable, give yourself retrieval cues while you are learning the information.