When you start talking cognitive psychology and neuroscience you can imagine how complicated things can get. The important concept in relation to cognitive ergonomics is that working memory is the memory you can use to process information and act upon. Working memory relates to ergonomics by helping you understand how complicated a task is and finding ways to make it easier to perform.
Working memory is easily illustrated by using memory units or information chunks. A memory unit is one piece of information. This chunk is then placed into your working memory and you can do something active with it. In a sequence of numbers a memory unit is represented by a single digit. Studies have shown that the normal person has 7 +/- 2 memory units. That is they can store seven numbers, words or other chunks in their active working memory.
If you are told a phone number you can probably dial it without forgetting it. If you have to remember the area code you might have a problem, unless you convert the information into chunks of information that is. A series of eleven single digit numbers
can be converted into six chunks by making them double digits.
You can reduce the memory units even more by creating chunks that let you recognize it as a telephone number.
When you can not chunk the information together in such a way as to keep it in your working memory then recall comes into play. You will dump the information chunks in your working memory and recall something from your stored memory to replace it.
If you use a computer as an analogy to the brain then working memory is the RAM. The rapid access memory is what is used by the processor. When the processor needs information to do something it gets it from the RAM. When the RAM no longer needs to provide that information it dumps it and retrieves the next piece of information the computer will need from the hard drive.
Another analogy is that your working memory is your brain's search engine. It is what filters and focuses the information stored in your brain (the internet) and it is where you can actually do something with that information.
Believe it or not that is how you theoretically operate every day. When you read you recall the word, place it into working memory, associate a memory of the meaning of that word and magically understand. Maybe it's not magic but that's the theory in a nut shell.
The working memory theory says that all of your active thinking and problem solving occurs in your working memory. Working memory is where your focus takes place as well. In this regard it is believed that a failure in working memory is responsible for a lot of learning disabilities such as Attention Deficit Disorder.
Working memory can be exercised to improve you performance and focus. The brain being a muscle, working out your working memory can make it stronger and better. Daily training of your working memory over a few weeks has been shown to provide significant improvement in focusing and processing capabilities. You can also manipulate your working memory functionality with mnemonic devices and other tricks.
Working memory has also been referred to as short-term store, immediate memory, primary memory, operant memory and provisional memory.