Working Memory

Susan Gathercole in her book ‘Working Memory and Learning: A Practical Guide for Teachers‘ defines working memory as “the ability we have to hold and manipulate information in the mind over short periods of time. It provides a mental workspace or jotting pad that is used to store important information in the course of our everyday lives”. Think of it as RAM inside a computer, compared to the hard disk drive of long term memory.

In a classroom environment, a child with impaired working memory may forget instructions or fail to complete their work. In the long term it can affect their ability to learn at the same speed as their peers (See study). Learning requires information to be held in working memory before it can be stored in long term memory.

Frank Amthor, Professor of psychology at the University of Alabama, states in his book ‘Neuroscience for Dummies‘ that working memory allows the brain to maintain a memory of a stimulus “some time after the stimulus has disappeared”. He goes on to say “what this means is that a goal can be pursued without the goal being continuously in sight”. Could this be the reason why some children can struggle with motivation?

Our working memory can only hold a limited amount in storage. George Miller of Princeton University discovered that working memory has a capacity of around seven pieces of information (“plus or minus two” – it varies slightly depending on the type of information being held). But oddly, this could be 7 numbers, or 7 sentences (similar to shortcuts to files in a computer).

A memory technique called “chunking” (the term was coined by Professor Miller) can enable us to hold more information in working memory. By breaking concepts down into discrete pieces or “chunks” of information, and then remembering a ‘cue’ to each chunk, we can remember larger amounts of information. It is a technique often used by professional chess players. Instead of memorising all the possible moves, they remember patterns of moves. We may use it to remember phone numbers, for example 04121655711 is easier to remember as 04-121-655-711. See skillstoolbox.com for more information on chunking. A way to use chunking in the classroom is to break tasks down into steps, or organise information into meaningful categories or patterns. This is much easier to remember than a long string of information.

This could be due to what Anders Ericsson and Walter Kintsch dub ‘long-term working memory’. The theory goes that we store information in long term memory and link this to our working memory through ‘retrieval structures’, holding only a few ‘cues’ or shortcuts in working memory. Wikipedia explains it this way: “Tasks such as reading, for instance, require to maintain in memory much more than seven chunks – with a capacity of only seven chunks our working memory would be full after a few sentences, and we would never be able to understand the complex relations between thoughts expressed in a novel or a scientific text. We accomplish this by storing most of what we read in long-term memory, linking them together through retrieval structures. We need to hold only a few concepts in working memory, which serve as cues to retrieve everything associated to them by the retrieval structures.”

There is evidence to suggest that working memory can also be affected by stress. Lowering stress and anxiety may help increase working memory capacity. There is much evidence to support the assertion that anxiety can exacerbate learning difficulties. Indeed it has been discovered that lowering anxiety can have a profound effect on improving the symptoms of dyslexia, and in my future posts I shall be covering the subject of anxiety and mental health.

Working memory seems to be directly related to the ability to filter out extraneous stimuli. The prefrontal cortex governs working memory ability by suppressing the amount of environmental sensory information being processed by the brain. A weakness in this area could result in irrelevant information being stored in working memory. (See Journal of Neuroscience).

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