What is the n-back task?
The n-back task asks you to watch a stream of items and say whether the current one matches the item from n steps earlier. It is one of the most used laboratory measures of working memory because it forces you to hold information in mind while constantly updating it.
Watching, holding and updating at once
The task descends from a 1958 study by Wayne Kirchner, who was looking at how short-term memory changes with age. He showed people a series of items, one at a time, and asked them to respond whenever the current item matched one from a fixed number of steps back. That running comparison is the “n” in n-back: at 1-back you compare against the last item, at 2-back against the item before that, and so on.
Each new item forces you to update what you are holding in mind and drop the oldest one, rather than simply remembering a fixed list. That is what makes it a working memory task rather than a short-term memory task: the content you are tracking keeps changing while you track it.
Why it feels harder than it sounds
2-back sounds easy until you try it. Most people can hold a handful of items in mind, but n-back asks you to update that small set on every trial, under time pressure, while ignoring the pull of items that were correct a step or two ago. Raising n by even one step increases the difficulty by more than it looks like it should on paper.
What a Memory Match score measures
Memory Match is Brain Gym’s version of the n-back task. Your score reflects accuracy and reaction time at the current n-level, and the level itself adapts: a strong set moves n up, a difficult one moves it back down. Like every score in this app, it describes your performance on this task, not a general memory or intelligence score.