Conflict-Frequency Affects Flanker Interference

Abstract

Performance in choice reaction time tasks deteriorates when an irrelevant stimulus feature is associated with an incorrect response (conflict condition). Such interference effects are reduced under conditions of increased conflict-frequency. Although models of cognitive control account for this modulation in terms of conflict-related attentional focusing on the target stimulus dimension, it is possible that the effect reflects practice with specific stimulus ensembles or stimulus feature-response contingencies. Using an Eriksen flanker task, we deconfounded the frequency of conflict trials and the frequency of specific stimulus ensembles (i.e., target-flanker conjunctions). In Experiments 1 and 2, flanker interference varied inversely with the frequency of conflict trials, irrespective of practice with specific target-flanker conjunctions, thereby disputing a stimulus ensemble learning account. In Experiment 3, however, flanker interference was reduced for specific flanker stimuli which occurred predominantly in conflict trials. Taken together, the findings are consistent with flanker-specific attentional adjustment or associative flanker-response priming.