The mechanics of memory

Did you know we forget 50% of what we learn within one day of learning it?

I know, shocking isn’t it? In my last two blogs I discussed what we as learning designers can do to make our learning content attention grabbing, and the impact of emotion in learning. In this blog I’m going to discuss what we can do to ensure learners remember our all important content.


Memory isn’t passive

As we process new information, we relate it to things we already know. This, in the world of neuroscience and psychology, is known as ‘cognitive economy’ (Gibson, 1969). This is an act of efficiency, whereby the mind creates categories for processing information1. In doing so, we group these categories together by association, and match patterns to reduce cognitive load.

So, when our learners are absorbing content, they are actively making relational links to other information that they already know. This knowledge and understanding will come from their long-term memory, rather than their short-term or working memory. So what is the difference between the two?


Working memory

Have you ever had to remember a number in the short term, so repeated it over and over until you can finally dial, recite or write it down? That’s working memory in action. Another more common example is being immersed in conversation: we need to remember what was just said, process it, and respond to it by giving our own opinion.

Working memory, or short-term memory, can be characterised by its:

  1. Limited capacity – learners can only store 7 (plus or minus 2) items at a time.
  2. Limited duration – the information can be forgotten easily with distraction or time.


Long-term memory

Conversely, long-term memory refers to the storage of information that can be retrieved over an extended period of time. It is the repository for knowledge and skills that humans use to make sense of what they are doing in the present.

Repeated recall is pivotal to ensuring long-term memory, as information that is frequently accessed from this ‘repository’ will become easier to recall over time. The aim of any learning designer is to ensure their content finds itself a home in the long-term memory of our learners – and one of the most popular ways of doing so is with ‘spaced repetition’.


Spaced repetition

The concept of spaced repetition relies upon Ebbinghaus’ ‘Forgetting Curve’ (1885). The Forgetting Curve is a visual depiction of the opening stat of this blog. It highlights how learners will struggle to recall more than 40% of information they learnt just one day later, and will have forgotten it almost completely over the coming months.

Spaced repetition fights the forgetting curve, by continually reminding learners of the content, as seen below.

By implementing spaced repetition, and increasing the space between each repetition, the brain is trained for better recall, shown in a flattening of the forgetting curve. As time passes and the space between repetitions grows, your brain will become equipped to recall the concept learnt without much cognitive load.


Retrieval practice

So, now we can see how spaced repetition helps aid long-term retention, what should be completed during these ‘repetition’ sessions? This is where retrieval practice comes in. Retrieval practice turns test taking on its head. Instead of being a tool to measure knowledge retention, they become the means by which learners attain knowledge. Rather than reviewing information, learners test knowledge recall in a ‘safe’ environment, where making a mistake doesn’t have a consequence. Immediate feedback on whether the answer was wrong or right, with an explanation of the right answer, is essential for helping recall and understanding.


Difficult to learn, easier to retain

Yes, you read that right.

The concepts we learn with difficulty are actually easier to retain. This is due to the amount of attention needed to learn it in the first place. Chances are, if the concept is trivially easy, the learner will not place their undivided attention on learning it.

We see this insight in practice in the world of gaming, and how people learn to play video games vs. their level of engagement. Little revelations throughout game play leads to your brain giving you a reward through a flash of dopamine, the ‘feel good’ neurotransmitter. This will encourage you to keep playing. If a game is too easy, you won’t get these flashes of dopamine, and you’ll likely get bored of the game. Game designers have this in mind through their planning process; as learning designers, we should echo that train of thought.

We know that challenges are when most learning occurs, and therefore this is when the most neural pathways are formed and fortified. By structuring learning experiences around this knowledge, we are encouraging learning and retention. A great way to design learning is following a pattern of ‘struggle – reward – struggle – reward’, upping the anti each time.


How can we put this into practice?

To utilise our knowledge on the mechanics of memory, the role of emotion in learning and how to grab attention, we can make small changes to our learning design right now. These include:

  • Keeping our design clear, removing any non-essential items that could be taking up working memory and displaying information in small, easily digestible chunks.
  • Summarise content at various stages and provide short mental breaks to reinforce a sense of progress – even a ‘well done’ will do.
  • Distribute information so that it is repeated and referenced frequently and ensure you give learners opportunities to review earlier concepts – to aid retention and recall.
  • Design shorter lessons to reduce the amount of time your learners are not paying attention. Keep the least important information in the middle of your course, so that you are optimising peaks in attention.
  • Finally, ensure your course content structure influences the way learners retain information.



1 How People Learn: Brain, Mind, Experience, and School: Expanded Edition, by National Research Council, Division of Behavioral and Social Sciences and Education, et al. Page 124