Grammatical deficits in bilingual Azari - Farsi patients with Parkinson's disease

Thirteen bilingual patients with Parkinson's disease and thirteen bilingual healthy controls matched for age, sex, formal education, and cognitive functioning were administered three linguistic tests of sentence comprehension and grammatical judgment in both native Azari (L1) and Farsi (L2) languages. Both groups had acquired L2 late (formal learning at primary school) and presented with mild cognitive impairment. Parkinson's patients had greater linguistic impairments in L1 than L2, and they had greater L1 and L2 impairments than healthy controls. These findings strongly replicate previous ones (Zanini et al., 2004) and suggest that L1 grammar processing mainly recruits cortical-subcortical language networks in agreement with the Declarative/Procedural model of language acquisition (Paradis, 1994; Ullman, 2001) and that general cognitive functioning ought to be carefully investigated with respect to linguistic impairments in bilingual subjects, especially in the case of adult subjects with neurodegenerative disorders.