N-back
Dual n-back: does this square sit where the last n ones sat, in the same colour, or both. Standard mode to learn it, endless to fail at it.
Two questions at once
An n-back task asks whether the current stimulus matches the one n steps ago. The usual version tracks one dimension. This one tracks two: position and colour, each with its own key.
**Z** for position, **X** for colour. Sometimes both.
Modes
**Standard** runs a fixed length and tells you how you did, which is the only way to actually learn the task.
**Endless** ends the moment you miss a match or miss reporting one.
Colour
Press **P** for the menu and you can swap the colours for letters. It is not decoration — colour and letter are separate channels here, and one of them may simply be easier for you to read.