SHORT AND LONG TERM MEMORY

The graph below shows how much we usually remember hours and days after a teaching session.

1. Surprisingly the amount we remember shortly after a lesson is often more than we remember immediately the lesson finishes! This is because our brain works automatically, sorting out what we have learnt and connecting it to ideas or skills we already know.

Immediately after the lesson we may be confused by all we have learnt, or if we are learning a skill we may be tired. If we come back after a short rest our brain has still been working on the problem and we may be able to remember more or be able to perform the skill better.

2. So far, however, the knowledge or skill we have learnt has only gone into our short-term memory.

How much of what you do or experience every day do you remember? Only a small fraction. If we remembered everything, our brain would become confused. Most of what we see, hear, feel or do goes into our short-term memory and soon gets forgotten. In fact forgetting is very important. People who cannot forget, and remember everything they ever do and everything that ever happens to them, have a form of mental illness.

As the graph shows, within one or two days we usually forget about 80% of what we learn. How can we prevent this? One way is shown in the following graph.

1. If we return to what we have learnt within about 24 hours of learning it, and revise our knowledge or practice the skill, our memory will go back up to 80% or more again. After this we begin to forget again, but more slowly.

2. If we return to the knowledge or skill again after another few days, again after a week and again after a month, each time we return to revise or practice, our memory will return to a high level again. Each time, forgetting will become slower, we will have forgotten less and it will be easier to recall. This is because this constant revision begins to change the knowledge or skill from our short-term to our long-term memory. If we come back to it again after 6 months this will probably place it firmly in our long-term memory.

3. Once we revise or practice many times, and something becomes part of our long-term memory, it may remain there for years or even a lifetime. It becomes part of us.

IN OUR TEACHING

• We must give students a chance to practice a skill frequently after learning it, and again during the first few weeks until it is in their long-term memory. A skill may then remain there for the rest of their lives.

For example, if you ride a bicycle for the first time you may fall off. The second time you may not fall – you have ‘learnt’ to ride. But if you don’t ride again for a few days you may fall off again the next time you try. However, if you keep practicing daily you may soon learn thoroughly and within a week you may wonder how you ever fell off. This skill will probably remain with you for the rest of your life, as long as you are fit enough to get onto a bicycle.

• In learning knowledge, we should do short periods of revision after a day, a week and a month. By that time the knowledge will be in our long-term memory and will remain there for years. Students, however, often make the mistake of learning something and then not revising it until just before an exam a few months later. By that time their revision may consist of learning almost the whole thing over again. Those who revise constantly may have very little revision to do just before an exam.