The flanker task, introduced by Eriksen and Eriksen (1974), is a classic measure of selective attention and response inhibition. On each trial the participant is shown a central target flanked on both sides by distractor items, and must respond to the target while ignoring the flankers.

This implementation uses the widely-adopted arrow variant: five horizontal arrows are shown in a row, and the participant reports the direction of the middle arrow. On congruent trials the flankers point the same way as the target (→→→→→, ←←←←←); on incongruent trials they point the opposite way (→→←→→, ←←→←←). Because the flankers are processed automatically and prime a competing response, incongruent trials yield slower and less accurate responses — the flanker effect (incongruent RT − congruent RT), a robust index of the cognitive control needed to suppress a prepotent but incorrect response.

Note on lineage: the original Eriksen & Eriksen (1974) task used letter flankers (e.g. HHHKHHH). The arrow-flanker variant used here is the version popularised by modern cognitive testing — notably the flanker component of the Attention Network Test (Fan et al., 2002) — and is the form most researchers reach for today. It measures the same construct with a language-independent, direction-based response.

The template ships with a short congruent + incongruent practice block, followed by 24 shuffled main trials balanced across the four design cells. Fixation, response-deadline and inter-trial-interval durations are exposed as re-usable parameters so researchers can adjust timing in the Open Lab study builder without editing individual screens, and all participant-facing text is exposed as translatable parameters.

Flanker Task