Second language experience and auditory cognitive control: Is more necessarily better?

Aims and objectives: The present study investigates the association between the degree of L2 experience and auditory cognitive control in Mandarin–English bilingual university students. Methodology: Two groups of bilinguals, differing in recent L2 instructional exposure, were compared. One group had received 168 hours of English instruction (more experienced; ME), and the other 84 hours (less experienced; LE). We further evaluated whether the ME group exhibited additional cognitive gains following an additional 84 hours of English instruction over a subsequent academic term. Data and analysis: Data were obtained from 157 participants using the auditory subtasks of the Test of Everyday Attention (TEA) to assess auditory attention control. Accuracy data were analyzed using mixed-effects models, controlling for relevant covariates including socioeconomic status (SES) and IQ. Findings/conclusions: The results indicated that even a modest amount of L2 exposure was associated with enhanced cognitive control, particularly in inhibitory control performance at pre-test. However, no further cognitive improvements were observed in the ME group following the additional instructional period. Originality: This study is among the first to extend the investigation of graded bilingual cognitive effects to the auditory domain using a longitudinal design. It provides novel evidence that auditory cognitive control is responsive to L2 experience, although such enhancements may plateau with continued exposure. Significance/implications: Findings support the domain-general benefits of bilingualism while highlighting potential limits to the cognitive effects of L2 learning. The results have implications for educational and cognitive training programs aiming to harness L2 learning for cognitive enhancement.