Do bilinguals show neural differences with monolinguals when processing their native language?

Highlights

•: Bilinguals and monolinguals neurally differ when producing language in their L1.
•: Monolinguals activated more receptive language areas during naming than bilinguals.
•: Bilinguals used a more widespread neural network than monolinguals during naming.

Abstract

The present research used fMRI to measure brain activity in passive listening and picture-naming tasks with a group of early high proficient Spanish–Catalan bilinguals, in which Spanish was dominant, and a group of Spanish monolinguals. Both tasks were conducted in Spanish and the effect of cognateness was studied. The behavioural results showed slow naming responses in bilinguals. The fMRI results revealed that bilinguals and monolinguals differed only during the picture naming task. Unlike previous results, obtained mainly with L2, monolinguals displayed more activity in receptive language areas and less activity in the posterior cingulate cortex and right STG in the picture-naming task than bilinguals. As far as we know, this is the first study to investigate the neural basis of L1 processing in bilinguals and monolinguals by performing the task in the same language and in a monolingual context. The results indicate more efficient use of language networks in monolinguals because bilinguals utilised a more distributed network, which may imply subtle processing disadvantages.

Keywords

Bilingualism;
fMRI;
Speech production;
Speech comprehension;
First language

: Corresponding author at: Departamento de Psicología Básica, Clínica y Psicobiología, Universitat Jaume I, Avda. Sos Baynat, s/n, E-12071 Castelló de la Plana, Spain.