Flanker Task

Background

The Eriksen flanker task, introduced by Eriksen & Eriksen (1974), is a classic measure of selective attention and response competition. Participants must respond to a central target letter while ignoring flanking letters that surround it.

Three Conditions

Congruent: Flankers match the target (e.g., HHHHH or SSSSS) — fastest
Neutral: Flankers are unrelated letters (e.g., XXHXX or XXSXX) — intermediate
Incongruent: Flankers map to the opposite response (e.g., SSHSS or HHSHH) — slowest

The Flanker Compatibility Effect

The flanker compatibility effect (FCE) refers to the finding that incongruent flankers slow responses by approximately 50–100 ms compared to congruent flankers. This demonstrates that nearby stimuli are processed involuntarily, even when they are irrelevant to the task. The visual system cannot fully filter out items that fall within the spotlight of spatial attention.

References

Eriksen, B.A. & Eriksen, C.W. (1974). Effects of noise letters upon the identification of a target letter in a nonsearch task. Perception & Psychophysics, 16, 143–149.
Eriksen, C.W. & St. James, J.D. (1986). Visual attention within and around the field of focal attention: A zoom lens model. Perception & Psychophysics, 40, 225–240.

A row of letters will appear on screen. Your task is to identify the CENTER letter only, ignoring the surrounding letters.

Press the key corresponding to the center letter:

F = H J = S

There are 72 trials total (~4 minutes). Respond as quickly and accurately as possible.

Flanker Task

Your Results