How the n-back task works
Wayne Kirchner described the task in 1958, and it has since become one of the main tools for studying working memory. The “n” is the distance back: in 1-back you compare with the previous letter, in 2-back with the letter two before, in 3-back with the letter three before. Every step up in n raises the difficulty sharply.
A 3-back example: K, M, R, K — a match (K was three steps back). Next: T, R — not a match (three steps back was M)… and so on for the whole game.
Does n-back raise intelligence?
In 2008 a study by Susanne Jaeggi and colleagues reported that “dual n-back” training improved scores on fluid intelligence tests. It caused a wave of interest, but later studies and meta-analyses painted a more modest picture: performance on the task itself improves reliably, while transfer to general intelligence is weak or disputed.
Our honest take: n-back is an excellent workout for concentration and holding information, and your progress on it is easy to see. Don’t expect “+10 IQ”, but do expect it to get easier to keep several things in mind at once in similar tasks.
How to practise
- Start small. If 3-back feels too hard, practise 2-back in your head on the same letters.
- Rehearse the window. Silently repeat the last three letters: “K-M-R… M-R-K…”.
- Don’t dwell on a mistake. If you miss a match, get straight back to the current letter or the whole window will slip.
- Short sessions. The task is tiring: 5 minutes of focused work beats 20 distracted ones.