Cognitive control in bilinguals: Advantages in Stimulus-Stimulus inhibition.

Bilinguals have been shown to outperform monolinguals at suppressing task-irrelevant information and on overall speed during cognitive control tasks. Here, monolinguals' and bilinguals' performance was compared on two nonlinguistic tasks: a Stroop task (with perceptual Stimulus-Stimulus conflict among stimulus features) and a Simon task (with Stimulus-Response conflict). Across two experiments testing bilinguals with different language profiles, bilinguals showed more efficient Stroop than Simon performance, relative to monolinguals, who showed fewer differences across the two tasks. Findings suggest that bilingualism may engage Stroop-type cognitive control mechanisms more than Simon-type mechanisms, likely due to increased Stimulus-Stimulus conflict during bilingual language processing. Findings are discussed in light of previous research on bilingual Stroop and Simon performance.