Post-conflict slowing effects in monolingual and bilingual children

Previous research has shown that bilingual children outperform their monolingual peers on a wide variety of tasks measuring executive functions (EF). However, recent failures to replicate this finding have cast doubt on the idea that the bilingual experience leads to domain-general cognitive benefits. The present study explored the role of disengagement of attention as an explanation for why some studies fail to produce this result. Eighty children (40 monolingual, 40 bilingual) who were 7 years old performed a task-switching experiment. In the pure blocks, three simple non-conflict tasks were performed in which children responded by pressing one of two response keys. In the conflict block, occasional bivalent stimuli appeared and created conflict because the irrelevant dimension was mapped to the incorrect response key. The results showed that these bivalent stimuli affected subsequent performance in the conflict block. For monolinguals, the effect of conflict was found for up to 12 trials after the appearance of the bivalent stimulus, but for bilinguals the effect disappeared after only two trials. The results are interpreted as evidence for faster disengagement of attention by bilingual children. Most studies examining EF in monolingual and bilingual children do not examine trial-by-trial adjustments following conflict, but these are essential considerations because relevant processing differences are masked when analyses are applied to data averaged across entire blocks.