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Functional MRI is based on changes in cerebral microvasculature triggered by increased neuronal oxidative metabolism. This change in blood flow follows a pattern known as the hemodynamic response function (HRF), which typically peaks 4-6 s following stimulus delivery. However, in the presence of cerebrovascular disease the HRF may not follow this normal(More)
BACKGROUND The syndrome of primary progressive aphasia (PPA) is diagnosed when a gradual failure of word usage or comprehension emerges as the principal feature of a neurodegenerative disease. OBJECTIVE To provide a quantitative algorithm for classifying PPA into agrammatic (PPA-G), semantic (PPA-S), and logopenic (PPA-L) variants, each of which is known(More)
This study examined the relationship between verb retrieval and verb-argument-structure properties in seven agrammatic aphasic patients using tasks requiring access to the verb's lexicon for both comprehension- and productionlike processes. Results showed intact comprehension of both nouns and verbs and noun naming, but impaired naming of verbs. Subjects(More)
The frontal aslant tract is a direct pathway connecting Broca's region with the anterior cingulate and pre-supplementary motor area. This tract is left lateralized in right-handed subjects, suggesting a possible role in language. However, there are no previous studies that have reported an involvement of this tract in language disorders. In this study we(More)
Primary Progressive Aphasia (PPA) is a behaviorally focal dementia syndrome with deterioration of language functions but relative preservation of other cognitive domains for at least the first two years of disease. In this study, PPA patients with impaired word finding but intact comprehension of conversational speech and their matched control subjects were(More)
This study examined the nature of verb deficits in 14 individuals with probable Alzheimer's Disease (PrAD) and nine with agrammatic aphasia. Production was tested, controlling both semantic and syntactic features of verbs, using noun and verb naming, sentence completion, and narrative tasks. Noun and verb comprehension and a grammaticality judgment task(More)
The cross-modal generalization effects of training complex sentence comprehension and complex sentence production were examined in 4 individuals with agrammatic Broca's aphasia who showed difficulty comprehending and producing complex, noncanonical sentences. Object-cleft and passive sentences were selected for treatment because the two are linguistically(More)
Neuroimaging and lesion studies suggest that processing of word classes, such as verbs and nouns, is associated with distinct neural mechanisms. Such studies also suggest that subcategories within these broad word class categories are differentially processed in the brain. Within the class of verbs, argument structure provides one linguistic dimension that(More)
Primary progressive aphasia (PPA) is a clinical dementia syndrome with early symptoms of language dysfunction. Postmortem findings are varied and include Alzheimer disease and frontotemporal lobar degeneration (FTLD), both tauopathies and TAR DNA binding protein (TDP-43) proteinopathies. Clinical-pathological correlations in PPA are complex but the presence(More)
The present study applies single-subject experimental design to examine (a) the acquisition and generalization of complex sentence production in agrammatism using Linguistic Specific Treatment (LST) and (b) the utility of syntactic theory in guiding hypotheses of treatment effects. LST trains construction and production of complex sentence structures. Four(More)