Awareness of working memory limits

In the previous step we conducted a small experiment about memorising two sequences of 18 letters. Both sequences had the same letters, just in a different order. The second set should be easier to remember because, for many of you, you will already know each of these acronyms. Your brain only has to remember the letters as six chunks of information rather than 18.

Reducing the number of chunks of information, in this case draws upon prior knowledge. But reducing the information being processed at any one point in time is not the only way to make room in the working memory network.

The effect of practice

The effect of practice on the brain can be seen in a study of adults learning complex mathematics. The images below show changes in activity in regions of the brain before and after practising complex multiplication problems (Delazer et al., 2003).

fMRI of participants who have practised a mathematical process. The left image shows highlights in many regions of the brain, including working memory networks. The right image shows fewer hotspots, with remaining hotspots at the back of the brain

The left image shows regions where activity has reduced as a result of practice and these are linked to working memory. The right image shows where brain activity was more active after practising.

Practice has shifted activity from working memory regions (in the front of the brain) to regions more involved with automatic unconscious processing (away from the front of the brain). In other words, practice helps consolidate freshly-learnt mental processes until we can do them almost without thinking, so reducing the burden on working memory. This is important because, when our limited working memory is liberated, it is ready to be occupied by new information and we are ready to move on and learn more.

Image credit

Images from Cognitive Brain Research, 18, Delazer, M. et al., Learning complex arithmetic, p. 76-88, Figure 2. One-sample t-test of the contrast untrained versus number matching ( p < 0.001) and Figure 3. One-sample t-test of the contrast untrained versus trained multiplications ( p < 0.01). Copyright (2003). Reproduced with permission from Elsevier.

Share this article:

This article is from the free online course:

The Science of Learning

National STEM Learning Centre