Large-scale neural network for sentence processing.

Our model of sentence comprehension includes at least grammatical processes important for structure-building, and executive resources such as working memory that support these grammatical processes. We hypothesized that a core network of brain regions supports grammatical processes, and that additional brain regions are activated depending on the working memory demands associated with processing a particular grammatical feature. We used functional magnetic resonance imaging (fMRI) to test this hypothesis by comparing cortical activation patterns during coherence judgments of sentences with three different syntactic features.

Neural basis for generalized quantifier comprehension.

Generalized quantifiers like "all cars" are semantically well understood, yet we know little about their neural representation. Our model of quantifier processing includes a numerosity device, operations that combine number elements and working memory. Semantic theory posits two types of quantifiers: first-order quantifiers identify a number state (e.

Alzheimer's disease and frontotemporal dementia exhibit distinct atrophy-behavior correlates: a computer-assisted imaging study.

Rationale And Objectives: The purpose of this study was to test the hypothesis that distinct patterns of gray matter atrophy are responsible for unique interruptions of the naming process in Alzheimer's disease (AD) and frontotemporal dementia (FTD).

Materials And Methods: Voxel-based morphometry (VBM) was performed to characterize at the voxel level the neuroanatomic changes that occur in AD and FTD based on high-resolution T1-weighted three-dimensional (3D) spoiled-gradient echo images of patients (AD, n = 12; FTD, n = 29) and healthy control subjects (n = 12). The cortical atrophy measurements were correlated with performance on behavioral measures of naming and related processes to identify brain regions that may contribute to this language function.

Neural basis for sentence comprehension deficits in frontotemporal dementia.

Many patients with frontotemporal dementia (FTD) have impaired sentence comprehension. However, the pattern of comprehension difficulty appears to vary depending on the clinical subgroup. The purpose of this study was to elucidate the neural basis for these deficits in FTD.

Neural basis for sentence comprehension: grammatical and short-term memory components.

We monitored regional cerebral activity with BOLD fMRI while subjects were presented written sentences differing in their grammatical structure (subject-relative or object-relative center-embedded clauses) and their short-term memory demands (short or long antecedent-gap linkages). A core region of left posterior superior temporal cortex was recruited during all sentence conditions in comparison to a pseudofont baseline, suggesting that this area plays a central role in sustaining comprehension that is common to all sentences. Right posterior superior temporal cortex was recruited during sentences with long compared to short antecedent-gap linkages regardless of grammatical structure, suggesting that this brain region supports passive short-term memory during sentence comprehension.