Language Control in Diglossic and Bilingual Contexts: An Event-Related fMRI Study Using Picture Naming Tasks.

The diglossic socio-linguistic situation in Arabic refers to the use of two language varieties in everyday life. Spoken Arabic (SA) is acquired first and used for everyday informal communication, while Literary Arabic (LA) is acquired at school and used for reading, writing and formal functions. Accordingly, the question whether LA functions as a second language had repeatedly been raised. In this study participants performed picture naming in SA in: (i) a simple naming context (SNc); (ii) a first language selection diglossic context mixing SA and LA (fLSc) and (iii) a second language selection bilingual context mixing SA and Hebrew (sLSc). Behavioral and event-related functional magnetic resonance imaging (fMRI) responses were analyzed to examine whether the comparison of picture naming in SA in different contexts will reveal differences related to control processes. Behavioral measures indicated that SA naming in SNc was easier than in fLSc and sLSc, while analysis of fMRI data revealed a significant effect of context. Region of interest analysis in six areas that were activated during the task exhibited two distinct patterns of differences in activation between fLSc and sLSc on the one hand, and SNc on the other. These results are explained in terms of the differential engagement of cognitive control modules and discussed in the light of current views suggesting that domain-general executive modules are adaptively recruited depending on the demands of the interactional context.