The amount of information that our brain retains in long-term memory is amazing, but it cannot (or at least does not) retain every piece of information reported by our senses. In large part what is retained is determined by short-term memory.
Short-term memory acts as an editor (filter) to determine what information is passed along to long-term memory. It seems as if only information that is considered important is selected for transfer to long-term memory. The best theories today indicate that short-term memory uses several criteria to decide what information is important enough to retain in long-term memory.
If short-term memory decides a piece of information is not important enough to pass along to long-term memory, then that information is lost forever – it is FORGOTTEN.
Short-term memory believes a piece of information is important if it seems likely that the information will be needed sometime in the future.
As I studied comments by many authors I concluded the consensus seems to be that short-term memory determines something to be important if it satisfies one of the following:
1) If you think carefully about the information,
2) If you perceive the information via multiple senses,
3) If related information already exists in long-term memory.
In summary, short-term memory believes information to be important if we are attentive to the information, think about the information, or relate it to other information already in long-term memory.
So new knowledge will find its way into our long-term memory if stimulus is adequate, we pay attention to it, and we have related retrievable prior knowledge in long-term memory. Willingham summarizes the process with the following two statements.
- “Memory is the residue of thought.” (Daniel T. Willingham).
- “All new learning requires a foundation of prior knowledge.” (Daniel T. Willingham).
If you don’t think about something very much, then you probably won’t want to think about it again, so it need not be stored.
If you do think about something, then it’s likely that you’ll want to think about it in the same way in the future.
Some research indicates that motivation is also a consideration, in that information relating to a subject of strong interest to a person, is more likely to be transferred to long-term memory.
Simple repetition does not convince short-term memory that an item is important and neither does the mere desire to remember something encourage short-term memory to retain that item.
We have just identified forgetting from short-term memory as the second opportunity for the learning process to be interrupted. We have also observed that attention, motivation, thinking about the information, and existence of related information in long term memory each tend to mitigate forgetting from short-term memory. Observe how forgetting from short-term memory, its mechanism, and its mitigation are indicated on the diagram.
If an item is not forgotten from short-term memory, it will be transmitted to long-term memory and the learning process has progressed one more step.