What Is Short Term Memory?

We use our short term memory every day. For example for -remembering a telephone number before dialling it or writing it down

• remembering what you have to get when you go shopping 
• holding directions in mind when you are driving 
• remembering that you need to check something in a few minutes
  

The Magical Number Seven

Unlike long term memory, the amount of information most people can hold in short term memory (numbers, food items, directions) is limited to around 7 items plus or minus 2. This short term memory capacity or 'memory span' has been called the 'magical number seven' in one of the most famous papers in cognitive psychology, by George Miller at Princeton University.

Working memory - a type of short term memory

But more important than just remembering information by rote is being able to do    mental operations on that information - to solve a problem, to figure something out, or reason through something to find an answer. For instance, remembering the changing locations of chess pieces while you run through a series of moves in your minds' eye, or figuring out a 15% tip ('the bill is 29.30. Call that 30. 10% of 30 is 3. Half of 3 is 1.5. 3 plus 1.5 is 4.5.').

The ability to hold information in mind for brief periods, and manipulate it mentally while screening out distracting, irrelevant information is a type of short term memory called    working memory. You have to do mental   work on the information, not just store it.

The capacity of working memory

The average capacity of working memory is much less than 7. Most people have a working memory capacity of about 2 or 3.

The short term memory--IQ link

People vary widely in their working memory capacity, and that these differences predict   general intelligence level as measured by standardized IQ tests. General intelligence depends on working memory because working memory affects a wide range of complex cognitive tasks besides figuring out a tip, involving reasoning problem solving, and making sense of things. We use working memory when we reason, plan and problem solve.

Working memory and general intelligence both share the same brain circuitry - the hippocampus and part of the frontal cortex of the brain called the    dorsolateral prefrontal cortex.

If    you can improve your short term (working) memory, you can improve your intelligence level

You can improve short term memory by over 65%--and intelligence by 40%

In 2008 brain scientists at the University of Bern in Switzerland and the University of Michigan in the States, demonstrated that by training on a working memory exercise called the   dual n-backimproves short term working memory capacity by over 65% over just 19 days of training. This improvement then results in an incredible 40% gain in intelligenceas measured by a version of the time limited Raven’s Advanced Progressive Matricestest - one of the most valid and highly regarded IQ tests for culture free intelligence.

The scientific study proving the IQ gain can be found here. You can find a downloadable version of this exercise here.