Eriksen flanker task
Examples of congruent stimuli would be HHHKHHH and CCCSCCC, where both the target stimulus and the flankers correspond to the same directional response.
Examples of incongruent stimuli could be HHHSHHH and CCCHCCC , where the central target letter and the flankers correspond to opposite directional responses.
[7] When subjects participate in the Eriksen Flanker Task, the anterior cingulate cortex, or the ACC, is activated.
On trial n + 1, the increased conflict will lead to more control, causing the distracting, or flanker, stimuli to be more readily ignored.
[8] The flanker paradigm was originally introduced as a way of studying the cognitive processes involved in detection and recognition of targets in the presence of distracting information, or "noise".
The 1974 study found that CRT was significantly greater in incompatible than compatible conditions, a difference termed the flanker effect.
Eriksen and Schultz (1979)[10] varied a number of features of the flanker tests, for example the size and contrast of the letters, or the use of forward or backward masking.
The arrow version of the flanker test has also been evaluated as a method of detecting impairment due to alcohol and drugs in drivers at the roadside,[14] demonstrating the importance of selective attention skills to spatial abilities such as vehicle operation.
[15] Studies involving sufferers of Parkinson's disease[16] found similar difficulties with suppressing incorrect response activation due to flanker interference, especially when under speed stress.
Moderate exercise, conversely, has been shown to improve performance on flanker tests,[17] suggesting efficiency of cognitive control operates constructively with physical activity.
Curiously, lowering serotonin levels via acute tryptophan depletion does not affect performance on a flanker task or corresponding EEG readings, but does alter cardiac response to incongruent stimuli, suggesting dissociation between cardiac and electro-cortical responses to errors and feedback when measuring cognitive flexibility.
[22] Still other research maintains the Gratton effect can be eliminated entirely if sequential biases are removed and that conflict adaptation failed to account for any performance results, suggesting instead support for a congruency switch cost model.
[28] An advantage of using ERPs is the ability to examine subtle differences in brain activity that do not appear in behavioral measures, such as response times or error rates.
