title: Subdivision of frontal cortex mechanisms for language production in aphasia.
abstract: Ventrolateral prefrontal cortex (VLPFC) has long been linked to language production, but the precise mechanisms are still being elucidated. Using neuropsychological case studies, we explored possible sub-specialization within this region for different linguistic and executive functions. Frontal patients with different lesion profiles completed two sequencing tasks, which were hypothesized to engage partially overlapping components. The multi-word priming task tested the sequencing of co-activated representations and the overriding of primed word orders. The sequence reproduction task tested the sequencing of co-activated representations, but did not employ a priming manipulation. We compared patients' performance on the two tasks to that of healthy, age-matched controls. Results are partially consistent with an anterior-posterior gradient of cognitive control within lateral prefrontal cortex (Koechlin & Summerfield, 2007). However, we also found a stimulus-specific pattern, which suggests that sub-specialization might be contingent on type of representation as well as type of control signal. Isolating such components functionally and anatomically might lead to a better understanding of language production deficits in aphasia.
authors.affiliation: Moss Rehabilitation Research Institute, Elkins Park, PA, USA. malathi@gwu.edu
authors.forename: Malathi
authors.initials: M
authors.lastname: Thothathiri
authors.forename: Maureen
authors.initials: M
authors.lastname: Gagliardi
authors.forename: Myrna F
authors.initials: MF
authors.lastname: Schwartz
mesh_terms: D000328:Adult; D000368:Aged; D001037:Aphasia / Q000209:etiology / Q000473:pathology*; D001930:Brain Injuries / Q000150:complications / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D005625:Frontal Lobe / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007802:Language; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009275:Names; D009483:Neuropsychological Tests; D014825:Vocabulary