title: Formulaic Language in Parkinson's Disease and Alzheimer's Disease: Complementary Effects of Subcortical and Cortical Dysfunction.
abstract: OBJECTIVE
  The production of formulaic expressions (conversational speech formulas, pause fillers, idioms, and other fixed expressions) is excessive in the left hemisphere and deficient in the right hemisphere and in subcortical stroke. Speakers with Alzheimer's disease (AD), having functional basal ganglia, reveal abnormally high proportions of formulaic language. Persons with Parkinson's disease (PD), having dysfunctional basal ganglia, were predicted to show impoverished formulaic expressions in contrast to speakers with AD. This study compared participants with PD, participants with AD, and healthy control (HC) participants on protocols probing production and comprehension of formulaic expressions.
  
  
  METHODS
  Spontaneous speech samples were recorded from 16 individuals with PD, 12 individuals with AD, and 18 HC speakers. Structured tests were then administered as probes of comprehension.
  
  
  RESULTS
  The PD group had lower proportions of formulaic expressions compared with the AD and HC groups. Comprehension testing yielded opposite contrasts: participants with PD showed significantly higher performance compared with participants with AD and did not differ from HC participants.
  
  
  CONCLUSIONS
  The finding that PD produced lower proportions of formulaic expressions compared with AD and HC supports the view that subcortical nuclei modulate the production of formulaic expressions. Contrasting results on formal testing of comprehension, whereby participants with AD performed significantly worse than participants with PD and HC participants, indicate differential effects on procedural and declarative knowledge associated with these neurological conditions.
authors.forename: Diana
authors.initials: D
authors.lastname: Van Lancker Sidtis
authors.forename: JiHee
authors.initials: J
authors.lastname: Choi
authors.forename: Amy
authors.initials: A
authors.lastname: Alken
authors.forename: John J
authors.initials: JJ
authors.lastname: Sidtis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000503:physiopathology*; D001927:Brain Diseases / Q000503:physiopathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007802:Language; D007806:Language Disorders / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009633:Nonverbal Communication; D010300:Parkinson Disease / Q000503:physiopathology*; D011581:Psychological Tests; D013060:Speech / Q000502:physiology