When Does the Neurological Basis of First and Second Language Processing Differ? Commentary on Indefrey

A large number of studies have been carried out over the last few years investigating whether the neurological representation of language differs between first (L1) and second (L2) language. In a recent review, Stowe and Sabourin (2005) concluded that both L1 and L2 typically activate the same areas, particularly the typical language areas (i.e., that there is no consistent qualitative difference between the neural architecture supporting processing of the two languages). The evidence suggested that this was so even when the L2 was learned relatively late. On the other hand, the extent and intensity of the activation quite frequently differed between the two languages, typically with increased activations for the L2. This was true for word paradigms, phonological processing, and sentence comprehension. This suggests, instead, a quantitative difference between the processing resources used by the two languages. Particularly, it suggests that L2 frequently cannot be processed as efficiently as L1, requiring more “work” from the same processing resources.