Controlling Two Languages: Cost-Benefit Analysis of Immersion in Second-Language Learning

One of the most efficient methods to learn a second language (L2) is through immersion in a country where that language is spoken. What aspects of language immersion enable adult learners to acquire an L2 more efficiently? An obvious consequence of immersion is more frequent and varied exposure to the L2, but another possibility is that immersion makes it easier to inhibit the first language (L1). If so, learning an L2 would involve cognitive mechanisms that lead to some benefits but also produce some cost to the learner, and if so, it would be of interest to know exactly how and to what extent does immersion negatively impact the learner? In this study, we tested a group of eleven English-speaking college students learning Italian through a study abroad program in Rome, Italy for a period of eight weeks. We predicted that language immersion would reduce fluency in the L1, in order to obtain the benefit of acquiring greater gains in fluency in the L2. To test this, participants completed a language history questionnaire and a verbal fluency task in both English and Italian on the first and last days of the term. On average, participants’ levels of Italian fluency increased and to a greater extent than any losses to their L1, which trended in the direction of an inhibitory effect, but not significantly so. These findings consider the possibility that foreign language acquisition is influenced primarily by frequency effects in the L2, and therefore not entirely due to an inhibitory mechanism on the L1