Roumyana Pancheva

An Event-Related fMRI Study of Syntactic and Semantic Violations

We used event-related functional magnetic resonance imaging to identify brain regions involved in syntactic and semantic processing. Healthy adult males read well-formed sentences randomly intermixed with sentences which either contained violations of syntactic structure or were semantically implausible. Reading anomalous sentences, as compared to well-formed sentences, yielded distinct patterns of activation for the two violation types. Syntactic violations elicited significantly greater activation than semantic violations primarily in superior frontal cortex. Semantically incongruent sentences elicited greater activation than syntactic violations in the left hippocampal and parahippocampal gyri, the angular gyri bilaterally, the right middle temporal gyrus, and the left inferior frontal sulcus. These results demonstrate that syntactic and semantic processing result in nonidentical patterns of activation, including greater frontal engagement during syntactic processing and larger increases in temporal and temporo-parietal regions during semantic analyses.

Neural correlates of lexicon and grammar: Evidence from the production, reading, and judgment of inflection in aphasia

Are the linguistic forms that are memorized in the mental lexicon and those that are specified by the rules of grammar subserved by distinct neurocognitive systems or by a single computational system with relatively broad anatomic distribution? On a dual-system view, the productive -ed-suffixation of English regular past tense forms (e.g., look-looked) depends upon the mental grammar, whereas irregular forms (e.g., dig-dug) are retrieved from lexical memory. On a single-mechanism view, the computation of both past tense types depends on associative memory. Neurological double dissociations between regulars and irregulars strengthen the dual-system view. The computation of real and novel, regular and irregular past tense forms was investigated in 20 aphasic subjects. Aphasics with non-fluent agrammatic speech and left frontal lesions were consistently more impaired at the production, reading, and judgment of regular than irregular past tenses. Aphasics with fluent speech and word-finding difficulties, and with left temporal/temporo-parietal lesions, showed the opposite pattern. These patterns held even when measures of frequency, phonological complexity, articulatory difficulty, and other factors were held constant. The data support the view that the memorized words of the mental lexicon are subserved by a brain system involving left temporal/temporo-parietal structures, whereas aspects of the mental grammar, in particular the computation of regular morphological forms, are subserved by a distinct system involving left frontal structures.

Late Merger of Degree Clauses

In this article, we propose that degree heads and degree clauses form a constituent not at the point where the degree head is merged, but after QR of the degree head and countercyclic merger of the degree clause. We derive a generalization originally outlined in Williams 1974 that the scope of the comparative degree quantifier is exactly as high as the site of attachment of the degree clause. This generalization is shown to follow from the derivational mechanism of countercyclic merger and a semantic property of the comparative degree head, namely, its nonconservativity

Measuring and comparing individuals and events

This squib investigates parallels between nominal and verbal comparatives. Building on key insights of Hackl (2000) and Bale & Barner (2009), we show that more behaves uniformly when it combines with nominal and verbal predicates: (i) it cannot combine with singular count NPs or perfective telic VPs; (ii) grammatical properties of the predicates determine the scale of comparison—plural marked NPs and habitual VPs are compared on a scale of cardinality, whereas mass NPs and perfective (atelic) VPs are (often) compared along non-cardinal, though monotonic, scales. Taken together, our findings confirm and strengthen parallels that have independently been drawn between the nominal and verbal domains. In addition, our discussion and data, drawn from English, Spanish, and Bulgarian, suggest that the semantic contribution of more can be given a uniform analysis.