Last Three · Memory Updating Test
Letters stream past one at a time and stop without warning. Your job: type the last three letters you saw, in order. Ten rounds.
How to play Last Three
Each round, a stream of 5–10 letters plays one at a time — you never know when it will stop. When it does, type the final three letters in the order they appeared. Ten rounds; your score is how many you got exactly right.
What it measures
This is a running memory span task. Because the stream length is unpredictable, you can't just memorise everything — you have to continuously update a small buffer, throwing out old letters as new ones arrive. That updating operation is a core component of working memory, closely related to what N-back trains.
Honest note: If you try to memorise the whole stream you'll drown — the skill is letting go of early letters. That's the point of the task, not a flaw in your memory.
What's a good score?
6–7 correct out of 10 is solid; 9–10 means your updating buffer is running very clean. The percentile we show is an estimate based on typical distributions, not a clinical norm.
FAQ
Any strategy tips?
Keep a rolling three-letter chunk in your head and overwrite the oldest letter each time a new one appears. Rehearse the current trio rhythmically — it feels awkward at first, then clicks.
How is this different from N-Back?
Both train updating. N-back asks you to compare each item to one N steps back; Last Three asks you to reproduce the freshest slice of the stream. Same muscle, different grip.
Keep training
Last Three is a running memory span task: because the letter stream stops unpredictably, you must continuously update a small mental buffer rather than memorise everything. Updating is one of the core executive functions, closely related to what N-back paradigms train.
Who benefits most — no medical claims, just where the research points
Keeping 'the latest state' in mind while new information arrives is the shape of most modern work.
Holding the tail of a sentence while parsing the rest leans on the same updating buffer.
A friendlier cousin of N-back that exercises the same updating muscle.