title: Speech errors in progressive non-fluent aphasia.
abstract: The nature and frequency of speech production errors in neurodegenerative disease have not previously been precisely quantified. In the present study, 16 patients with a progressive form of non-fluent aphasia (PNFA) were asked to tell a story from a wordless children's picture book. Errors in production were classified as either phonemic, involving language-based deformations that nevertheless result in possible sequences of English speech segments; or phonetic, involving a motor planning deficit and resulting in non-English speech segments. The distribution of cortical atrophy as revealed by structural MRI scans was examined quantitatively in a subset of PNFA patients (N=7). The few errors made by healthy seniors were only phonemic in type. PNFA patients made more than four times as many errors as controls. This included both phonemic and phonetic errors, with a preponderance of errors (82%) classified as phonemic. The majority of phonemic errors were substitutions that shared most distinctive features with the target phoneme. The systematic nature of these substitutions is not consistent with a motor planning deficit. Cortical atrophy was found in prefrontal regions bilaterally and peri-Sylvian regions of the left hemisphere. We conclude that the speech errors produced by PNFA patients are mainly errors at the phonemic level of language processing and are not caused by a motor planning impairment.
authors.affiliation: Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-4283, USA. ash@babel.ling.upenn.edu
authors.forename: Sharon
authors.initials: S
authors.lastname: Ash
authors.forename: Corey
authors.initials: C
authors.lastname: McMillan
authors.forename: Delani
authors.initials: D
authors.lastname: Gunawardena
authors.forename: Brian
authors.initials: B
authors.lastname: Avants
authors.forename: Brianna
authors.initials: B
authors.lastname: Morgan
authors.forename: Alea
authors.initials: A
authors.lastname: Khan
authors.forename: Peachie
authors.initials: P
authors.lastname: Moore
authors.forename: James
authors.initials: J
authors.lastname: Gee
authors.forename: Murray
authors.initials: M
authors.lastname: Grossman
mesh_terms: D000368:Aged; D001921:Brain / Q000473:pathology; D005260:Female; D006801:Humans; D007807:Language Tests; D008037:Linguistics; D008279:Magnetic Resonance Imaging; D008297:Male; D033262:Narration; D009483:Neuropsychological Tests; D010700:Phonetics; D057178:Primary Progressive Nonfluent Aphasia / Q000473:pathology; D013060:Speech; D013068:Speech Production Measurement