Arrow Flanker Task

Background

The Arrow Flanker Task is a widely used test of cognitive control and interference resolution. Originally introduced by Eriksen and Eriksen in 1974 as 'the Eriksen Flanker Task', the Flanker paradigm was later streamlined and simplified for cognitive research and clinical testing.

The introduction of the arrow-based version of the Eriksen Flanker Task is credited to a publication by E.J. Stoffels and M.W. van Der Molen in 1988 who used left and right pointing arrows in addition to the original Eriksen letter stimuli. In the Arrow Flanker Task participants have to respond to a middle arrow that either points to the left or to the right and is flanked on either side by 2 additional arrows that either point in the same direction as the target ('congruent' arrows) or in the opposite direction ('incongruent' arrows). The direction that the response-irrelevant flankers point to reliably interferes with target responses.

The move from an arbitrary "letter-to-hand" mapping to a "direction-to-hand" mapping not only strengthened the notion that it's the brain's difficulty to suppress a dominant motor response resulting in the observed Flanker effects but it also made the task far more intuitive and thus accessible to a wider audience.

The Arrow Flanker Task was further fine-tuned and is now widely used in cognitive research and clinical assessments, e.g. as part of the NIH Toolbox Cognition Battery, as a reliable, non-verbal measure of executive function.

The Millisecond implementation of the Arrow Flanker task is based on the publication by K. Richard Ridderinkhof and colleagues in 1997 but uses a simplified design (e.g. the stimulus-response key assignment stays fixed). The task can be run on traditional keyboard devices with left and right response keys as well as on touchscreens with left and right response buttons.

Task Procedure

After the presentation of a central fixation cross (1000ms), five arrows appear in the center of the screen. The middle arrow either points to the left or the right. The flanking arrows either all point in the same direction as the target ('congruent trial') or all of them point in the opposite direction ('incongruent trial').

The test starts with a practice session of 8 trials. Practice trials provide performance feedback. Participants must get at least 75% of trials correct to move to the test trials. The test consists of 24 trials (12 congruent and 12 incongruent trials).

Keyboard Response Input

The left response key is the 'Q' key and the right response key is the 'P' (location of keys on the left and right side of a QWERTY keyboard). The participant has 1750ms to press the left (Q) or right response (P) key that corresponds to the direction that middle arrow is pointing to. Once the response key is pressed, all stimuli are removed and the screen is blank for 500ms before the next trial starts.

Touch/Mouse Response Input

The left and right response buttons are simple buttons on the screen. On touchscreen devices they can be touched with the finger or stylus and on non-touchscreens they can be clicked with a computer mouse. The participant has 1750ms to press the left or right response button that corresponds to the direction that middle arrow is pointing to. Once the response button is pressed, all stimuli are removed. At this point, participants are asked to return their response finger/mouse to a home base button that is located in between the two response buttons and thus, equidistant to both.

What it Measures

The Arrow Flanker Task is a measure of cognitive control and interference resolution

Psychological domains

• Executive Control: Ability to resolve conflict among competing stimuli, involving response inhibition and decision-making
• Inhibitory Control / Response Inhibition: Ability to override automatic/dominant responses that interfere with one's goals
• Selective Attention: Ability to select information from sensory input by directing attention to a specific location in space

Main Performance Metrics

• Accuracy Measures: Proportion correct responses in the varying noise conditions as a measure of conflict resolution success
• Latency Measures: Mean correct response times in the varying noise conditions as a measure of conflict resolution speed

Psychiatric Conditions

Arrow Flanker performance tends to be impaired in patients with the following conditions.

• Attention Deficit Hyperactivity Disorder (ADHD)
• Autism Spectrum Disorder (ASD)
• Schizophrenia
• Parkinson's Disease (PD)

Test Variations

References

Search Google Scholar for peer-reviewed, published research using the Inquisit Arrow Flanker Task.

---

Ridderinkhof, K. R., van der Molen, M. W., Band, P. H., & Bashore, T. R. (1997). Sources of interference from irrelevant information: A developmental study. Journal of Experimental Child Psychology, 65, 315–341.