The spectre of postgraduate examinations haunts all trainees. Whether you’re surgical, GP, BPT or in critical care – we all have these milestones to conquer along the way.

These exams often come full circle – testing basic science materials that have been readily forgotten in the years that have elapsed since medical school.

The ability to forget is quite remarkable. It was measured by German psychologist Herman Ebbinghaus in the 1880s, and gave birth to the famous ‘forgetting curve’. 

Ebbinghause would recite trigrams – nonsense strings of three letters (think ZOB, MAK, TIB) – in batches of 13. Once he could recall 11 out of the 13 trigrams, he would consider the deck learnt. He then measured the time it took to recall these cards at 20 minutes, 1 hour, 9 hours, 1 day, 2 days, 6 days and 31 days. The forgetting curve looks something like this:

Retention of data.jpg

After just 20 minutes you’ve forgotten 42% of what you just learnt!

Part of this is evolutionary – it doesn’t make sense to remember every single detail of your day. What a waste of brain energy. The other part is infinitely frustrating – all of those facts being forgotten at an exponential rate!

But Ebbinghaus’ insights also give us a method to combat the curve. With appropriately spaced repetitionthe curve begins looking like this:

Retention of data (2).jpg

With repeated interval exposure we remember more and more, and slowly encode these facts into long term memory. For those of you studying pharmacology, it almost looks like a drug trying to reach steady state:


ssplot.jpg Graph from:

There are programs that use the data from the forgetting curve to expose you to these facts just as you are about the forget them. This has been shown to get the most yield with regards to encoding into long term memory. These programs are called spaced repetition systems (SRSs).

The classic is Anki – the desktop version is free. I first heard of this app in How We Learn by New York Times medical and science reporter Benedict Carey – a great read packed with other study and memory hacks. I also came across it in Fluent Forever by Gabriel Wyner, a how-to for language learners. Apparently Anki is a staple among language students.

Like any flash card app, simply put a question on the front (e.g. define clearance) and put the fact that you remember on the back (the volume of blood cleared per unit time, CL=elimination/plasma drug concentration).

If you get it right, the card will be shuffled to the back, and you’ll be tested again at the appropriate interval. If you get it wrong, it will be placed at the ‘top’ and you’ll be re-exposed to it much sooner.

You’ll find that the more times you get a card correct, the longer the interval will be until you are tested next.

As well as exploiting the forgetting curve, this strategy harnesses the power of active recall. Only by going through the process of unearthing the fact from your short term memory can it be encoded into your long term memory.

Now I agree, medicine is not something that can be rote learnt, but there are times that call for effective memorisation – namely exams.

So go ahead and embrace the gifts of Ebbinghaus – it would be a shame if all of those years of memorising nonsense trigrams went to waste. More importantly, utilise the tools available to prevent the slide down the forgetting curve.

There are multiple programs that will provide an SRS – Anki is just one – so go for a bit of trial and error until you find the one that you like.


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