A dissociation between syntactic and lexical processing in Parkinson's disease

Publication date: August 2019Source: Journal of Neurolinguistics, Volume 51Author(s): Karim Johari, Matthew Walenski, Jana Reifegerste, Farzad Ashrafi, Roozbeh Behroozmand, Mostafa Daemi, Michael T. UllmanAbstractParkinson's disease (PD), which involves the degeneration of dopaminergic neurons in the basal ganglia, has long been associated with motor deficits. Increasing evidence suggests that language can also be impaired, including aspects of syntactic and lexical processing. However, the exact pattern of these impairments remains somewhat unclear, for several reasons. Few studies have examined and compared syntactic and lexical processing within subjects, so their relative deficits remain to be elucidated. Studies have focused on earlier stages of PD, so syntactic and lexical processing in later stages are less well understood. Research has largely probed English and a handful of other European languages, and it is unclear whether findings generalize more broadly. Finally, few studies have examined links between syntactic/lexical impairments and their neurocognitive substrates, such as measures of basal ganglia degeneration or dopaminergic processes. We addressed these gaps by investigating multiple aspects of Farsi syntactic and lexical processing in 40 Farsi native-speaking moderate-to-severe non-demented PD patients, and 40 healthy controls. Analyses revealed equivalent impairments of syntactic comprehension and syntactic judgment, across different syntactic structures....
Source: Journal of Neurolinguistics - Category: Speech-Language Pathology Source Type: research