Most of us probably have an implicit understanding of what memory is: It's the information we have in our heads, right? But when looking at memory more closely, we'll see that it's actually a great deal more complex than that. The two first distinctions we come across are long term memory and short term memory. In this article, we will look at the fascinating topic of short-term memory
Short-term memories are memories that are held in the brain for a very brief amount of time, seconds rather than minutes, and is also very limited in how much information it can hold. One example that most people can relate to is trying to remember a phone number long enough to dial it. It can be surprisingly challenging. Another example is one you're already doing while reading this text: In order to understand the end of a sentence, your brain must hold on to the information given at the beginning of a sentence. This is usually no problem (except when the author forgets to put in a full stop and allows the sentence to become a run-away sentence) but trying to recall any particular sentence half an hour later is usually near impossible. So, short-term memory allows us to work with information without necessarily storing every little tiny thing for the long term.
If we continue the example of the sentence though and imagine this sentence is part of a script for a theatre play, the actor is required to remember the sentence word for word. This is done by moving it on to long-term memory. Repetition of the sentence is key here but also simply the intent to remember a certain piece of information helps the brain to move the information into the long-term memory.
I mentioned above that the short term memory can only hold a limited amount of information but this number can be increased either by repetition or by clumping things together. Let's return to the example of a phone number. Remembering each number alone is difficult because it makes each number one item in the brain but if they are combined they can be much more easily recalled. And if they can be combined in a way that has an association, they can be even more easily remembered. For instance: 1960171512301620. This number would be nearly impossible to remember even long enough to write it down if each number was remembered alone. But split it up like this, and remember the numbers as years, and suddenly the task is not nearly as hard: 1960 1715 1230 1620. This trick utilizes both the grouping together of information and association by making it into years rather than simply numbers of no particular meaning.
A game you can play to test your short-term memory against someone else is a game where one person starts: "I pack my bag with..." and then mentions an item. The next person must then continue with: "I pack my bag with...", mention the first item and then add a second. The game goes on like this until someone at some point fails to remember an item. In this game the memory is helped by repetition, meaning it can hold more information than usual, but it still challenges your short-term memory.