Threshold effects of interactional context on attentional control.

Introduction: The debate surrounding bilingual cognitive advantages has prompted researchers to focus on the dynamic regulatory mechanisms of bilingual experience. Methods: Using a cross-task priming paradigm, the present study investigated the threshold effects of bilingual interactional contexts on attentional control. In Experiment 1, 60 unbalanced Chinese-English bilinguals completed a single picture-naming task involving four interactional contexts (monolingual English, monolingual Chinese, bilingual, and voluntary naming). This was followed by an anti-saccade task. The results showed that a single exposure to dual-language contexts did not facilitate attentional control. Instead, it induced resource depletion, as evidenced by significantly prolonged reaction times. In Experiment 2, 40 bilinguals completed two consecutive blocks of the same picture naming task before performing the anti-saccade task. Results: The results showed that, compared with monolingual contexts, repeated exposure to dual-language contexts significantly enhanced attentional control, as indexed by faster reaction times and higher accuracy. Moreover, the facilitatory effect was stronger in the bilingual context than in the voluntary naming context. The contrast between the two experiments reveals a cumulative threshold of cognitive load: a single exposure falls below the threshold, resulting in resource depletion, whereas repeated exposure surpasses it, triggering adaptive reorganization of attentional control. Discussion: The present study provides preliminary evidence that the influence of bilingual contexts on attentional control may follow a threshold effect, offering a potential mechanistic account of bilingual cognitive plasticity.