When a person doesn’t have a pen and is given a phone number they must immediately call, can they remember that phone number (usually 7 digits), for more than a few seconds? It can be a difficult thing remembering the digits in order and reserving them in what is called the short-term memory, which may also be termed active or working memory. Most people given the phone number would be able to remember at least 5 numbers, a lot of people can recall all 7 of them, and a few could remember an even longer number. As the seconds pass though, the memory wouldn’t be maintained, unless the person kept the number in memory by repeating it pretty regularly.
Most models of the ways humans remember posit that there are three memory systems. Though short-term memory is short in duration, lasting about 20 seconds for most things, there is an even shorter memory process, called sensory memory. This takes in visual and audio (seen and heard) information and keeps a copy of it. However we tend not to remember any of this, since these copies last for less than a second.
Quite in contrast to short-term memory and sensory memory is long-term memory. This stores all the things we have remembered, and according to many psychologists, many things we don’t know we’ve remembered. It’s a huge network or data storage unit, constantly collecting more information as people progress through life. When people want to convert a short-term memory into a longer term one, it usually has to be given specific meaning, or it doesn’t remain.
The reason the example in the first paragraph was used is because studies on short-term memory are often conducted by asking people to remember number digits. In the 1950s, and since then, it’s been shown repeatedly that people reliably can remember 7 plus or minus 2 digits. Those who seem have to have the best short-term memory of digits may also have better long–term memory of digits, and they do this by a process called chunking. Instead of remembering a seven-digit sequence, they tend to remember a three and four digit sequence. People who can remember telephone numbers, social security numbers and the like usually have evolved some process of chunking the numbers so they are easy.
The distinction between short-term and long-term memory is an important one and can help people learn and memorize. It really lets people know that learning style has to encompass a way to make things meaningful so that memories move to the area of the brain where they will be remembered for longer than a few seconds. There are many different learning strategies that can assist in this respect.