N-Back Task

The N-back task (Kirchner, 1958) is the most widely used laboratory measure of working memory updating. On each trial participants see a letter and must indicate whether it matches the letter presented N trials earlier. This implementation uses the standard 2-back level, requiring participants to hold a rolling two-item buffer and compare each new letter to the letter seen two positions back.

The task captures the critical working memory sub-process of continuous updating: the buffer must be refreshed every trial — the oldest item dropped, the new item encoded — while still holding the previous item for one more comparison. This makes 2-back performance strongly predictive of fluid intelligence, attentional control, and everyday working memory capacity.

The template ships with a 12-trial practice block (with per-trial feedback) followed by 60 main trials (18 targets, 30%). Targets fall at irregular positions, so no counting rhythm predicts them, and the sequence includes 12 interference lures: letters that repeat one or three trials back instead of two. Lures reward precise tracking of the 2-back position over a vague sense of familiarity (Kane et al., 2007). All timing parameters and participant-facing text are exposed as researcher-controllable parameters, including translatable instruction strings.