Differential impacts of natural L2 immersion and intensive classroom L2 training on cognitive control

The relationship between bilingualism and cognitive control has been controversial. We believe that the discrepant findings are likely driven by the complexities of the bilingual experience, which is consistent with the Adaptive Control Hypothesis. The current study investigates whether the natural language immersion experience and the classroom intensive language training experience have differential impacts on cognitive control. Among unbalanced Chinese-English bilingual students, a natural L2 (second language) immersion group, an L2 public speaking training group, and a control bilingual group without immersion or training experience were compared on their cognitive control abilities, with the participants' demographic factors strictly controlled. The results showed that the L2 immersion group and the L2 speaking group had faster speed than the control group in the Flanker task, whereas the L2 immersion group had fewer errors than the other two groups in the Wisconsin Card Sorting Test (WCST). These results generally provide evidence in favour of the Adaptive Control Hypothesis, specifying that natural L2 immersion and L2 public speaking training experiences are distinctively related to cognitive control. The current study is the first of its kind to link specific bilingual experiences (natural L2 immersion vs. intensive L2 public speaking) with different components of cognitive control.