With so much current interest in understanding how humans think, it seems ironic that we are increasingly using technology to replace our own brains. First came calculators to blunt the arithmetic skills that most brains are well suited to. Now, with ICT making information so readily retrievable, we are in danger of forgetting how to remember. I want to argue the case for returning memory to the classroom. Not the tedious rote learning of old, but the investigation of how human memory works. Experiments in memory are an excellent introduction to the brain - and memorising can be enjoyable, too.
Do brains remember in the same way as computers? There are some similarities. For example brains have a short-term, temporary memory (equivalent to the computer screen) and permanent long-term memory (our hard disk). How big is your short-term memory? Give the class three seconds to read a five digit number (48239, say). Nearly all of them will recall it perfectly. Increase the number to seven digits, and the majority will still be spot on. Now go up to nine digits (try 829176853). Only a couple of the class will remember the number accurately. Seven random digits are most people's limit for what they can hold in their mind without formally learning and storing the number. It is convenient that most local telephone numbers only have seven digits.
The differences between computers and brains are also intriguing. One important difference is that computers are, in their own way, infallible. What you give them is what they give you back. Not so with brains. If you have a clock in your classroom, cover it up before the start of a lesson. Ask your class to draw a picture of the clock. Although they gaze at it every day, the chances are that many will get it wrong - for example numerals will be inserted where the classroom clock only has ticks. The human memory here is giving back its interpretation of what it sees, not the image that it observed. (Incidentally, do you have a clock at home with Roman numbers on it? If so, what does the number four look like? You probably think it says IV because that's what you have learned a Roman four looks like. In fact, almost certainly the four on the clock is IIII.) Unlike computers, the brain also uses external stimuli to help it remember. For example, eye movements are believed to play a part in recalling information. By pointing in different directions the eyes stimulate different parts of the brain.
Investigate this by grouping your class into threes. One member of each group is the subject to be monitored, the second is the observer and the third stands behind the subject and asks questions from a prepared list. The questions should examine different types of memory: "Imagine the smell of sausages. What does Concorde look like? Multiply 7 by 8 and take away 4." There is some evidence that when visualising, a person points the eyes to the left, and when calculating they look to the right. What do your class find? Note: it's important that the pupils being observed don't know what the person watching them is looking for.
Most fascinating of all is the tendency of the brain to remember using images and associations. The Greeks used to memorise using the "room method". A demonstration of this can have quite spectacular results. To make it fair, you will need two lists of 10 items. Give the class a minute to memorise the first list, then check their recall scores. The average score will be six or seven out of 10. Now give them the second list, but this time help them to "store" the items around your classroom. Let's use the list banana, scissors, shark, slippers, car keys, toilet paper, trumpet, dog food, moustache, broomstick. Then look around your classroom and pick out ten familiar features as you move your gaze around clockwise.
The room method works by linking each of the items in your list to some feature in the room. Start with the blackboard, for example. They want to remember the first item, a banana. The trick is to create an image that combines the blackboard and a banana. Imagine a banana splatting into the blackboard (the sillier the image, the more memorable it is). The next thing in the room that stands out may be a world map. Imagine this has been cut to pieces by scissors so that all the countries are missing. Keep going around the room, picking out a feature and creating an image which includes the item to remember. Picture the books on the shelf as shark's teeth, a huge slipper keeping the flowers warm, and so on.
Now just by looking around the room the class should be able to recall each of the 10 items - and in any order you choose. It's an impressive trick, but it is also a great illustration of how the brain is at its best when it is presented with information that is linked to a familiar pattern.
There are plenty more experiments to try. Can people remember things that happened to them before they were four? Which poems are most memorable, and why? Do smells conjure up memories? In an age where electronics are taking over, it's good to be reminded that nature endowed us with a pretty impressive computer of our own.
Rob Eastaway is author of 'The Memory Kit'. Element Children's Books, pound;9.99