Why do we forget?
Some of our memories last a lifetime, while others disappear from our memory immediately. Researchers have proposed several explanations why we actually forget things, emphasizing difficulties in encoding, storage, and retrieval.
Encoding Failure
If many psychologists state that memory in some respects is like a giant library, one reason why we tend to forget information is that the book wasn’t put on its right place. Most of the things that we experience, and later on don’t remember, are not because that we forget, it’s because we fail to encode the information into long-term memory in the first place. This is understandable since our mind can’t remember every single thing that we experience.
Decay of the memory trace
When we encode our memories in order to store, one early explanation why we forget was the decay theory. When our memories have been stored a long time in our mind, some of them will eventually disappear. As time passes by, we might not use some of our memories for several years. Then the physical memory trace in the nervous system fades away. The decay theory fell quickly into disfavor among the scientists since they couldn’t identify what physical memory traces were and where they were located.
The decay theory states that the longer the interval of disuse between learning and recall, the less can be recalled. This was also a problem for the psychologists. When participants learned a list of words and were retested, they often remembered more during the second test than during the first. This phenomenon is called reminiscence and it seems inconsistent with the concept that a memory decays over time.
According to the interference theory, we forget information because other items in long-term memory impair our ability to retrieve it. Many psychologists view interference as a major cause of forgetting, especially cognitive ones.
The interference theory can be divided in two different parts; the proactive interference and the retroactive interference. The proactive interference occurs when material learned in the past interferes with recall of newer material. The retroactive interference occurs in the opposite direction. Here newly acquired information interferes with the ability to recall information learned at an earlier time.
Some researchers believe that interference is caused by competition among retrieval cues. When different memories become associated with similar cues, confusion can result and we will call up the wrong memory.
Motivated Forgetting
There are some psychologists who think that there’s another reason why we forget things. They maintain that motivational processes, such as repression, may protect us by blocking the recall of anxiety-arousing memories. The concept of motivated forgetting is not totally supported. Some evidence supports it, and other evidence does not.
Amnesia
Amnesia takes several forms and it’s the most dramatic instances of forgetting. Consider a football player who is knocked out in a concussion. He regains his consciousness and cannot remember the events just before being hit. He is experiencing retrograde amnesia.
Anterograde amnesia refers to memory loss for events that occur after the initial onset of amnesia. The third and final type of amnesia is called infantile amnesia; an inability to remember personal experiences from the first few years of our lives. One possibility of what causes infantile amnesia is that brain regions responsible for encoding long-term memories are still immature in the first years after birth.
Prospective Memory
Have you ever forgotten to buy something important or to mail a letter? In contrast to retrospective memory, which refers to memories of past events, they concern the future. People forget to do things very often and this is a very interesting are for many psychologists. From my own experiences I know that my grandparents tend to forget to do things much more often than I do.
When you retrieve information from long-term memories, you don’t remember the event very clear. Often you only remember bits and pieces so it’s not a very detailed recall. Forgetting can have serous consequences. Imagine a witness who is supposed to testify. If she doesn’t remember exactly what she saw or heard, then things can go really bad.
Bibliography
- Psychology, Frontiers and Applications – Michael W. Passer, Ronald E. Smith
- Approaches to psychology – William E. Glassman
– “Glömska”