Sergey Avrutin

An Event-Related fMRI Study of Implicit Phrase-Level Syntactic and Semantic Processing

Most neuroimaging studies of language function to date use a block-subtraction paradigm in which images acquired during relatively long periods of target stimuli are compared to those acquired during a control period. These studies typically require an overt response on the part of the subject, usually some type of discrimination or grammatical judgment by button press, or silent word generation. Results from studies of syntactic and semantic processing have generally been compatible with the classical correlation to Brocas area and Wernickes area, respectively. Recently, functional magnetic resonance imaging (fMRI) studies departing from the block-subtraction paradigm in favor of event-related fMRI paradigms have been reported. We have extended the use of this approach to examine implicit (i.e., without an explicit task on the part of the subject) syntactic and semantic processing at the phrasal level, using visually presented verb phrases. Left BA 44 is more strongly activated for the syntactic condition than the semantic condition. BA 45, 10, and 46 show laterality differences: mostly left-lateralized for the syntactic condition and right-lateralized for the semantic condition. We also find activations of the inferior parietal lobe, consistent with a visual oddball response reported previously, and the anterior cingulate gyrus (BA 32), implicated for attention and memory-related processes in numerous studies.

Slower-than-normal syntactic processing in agrammatic Broca's aphasia: Evidence from Dutch

Abstract Studies of agrammatic Brocas aphasia reveal a diverging pattern of performance in the comprehension of reflexive elements: offline, performance seems unimpaired, whereas online—and in contrast to both matching controls and Wernickes patients—no antecedent reactivation is observed at the reflexive. Here we propose that this difference characterizes the agrammatic comprehension deficit as a result of slower-than-normal syntactic structure formation. To test this characterization, the comprehension of three Dutch agrammatic patients and matching control participants was investigated utilizing the cross-modal lexical decision (CMLD) interference task. Two types of reflexive-antecedent dependencies were tested, which have already been shown to exert distinct processing demands on the comprehension system as a function of the level at which the dependency was formed. Our hypothesis predicts that if the agrammatic system has a processing limitation such that syntactic structure is built in a protracted manner, this limitation will be reflected in delayed interpretation. Confirming previous findings, the Dutch patients show an effect of distinct processing demands for the two types of reflexive-antecedent dependencies but with a temporal delay . We argue that this delayed syntactic structure formation is the result of limited processing capacity that specifically affects the syntactic system.

Reference Assignment: Using Language Breakdown to Choose between Theoretical Approaches.

We report results of an experimental study with Dutch agrammatic aphasics that investigated their ability to interpret pronominal elements in transitive clauses and Exceptional Case Marking constructions (ECM). Using the obtained experimental results as a tool, we distinguish between three competing linguistic theories that aim at determining principles responsible for pronoun distribution: Government and Binding (Chomsky, 1981), Reflexivity (Reinhart & Reuland, 1993), and Primitives of Binding (Reuland, 2001). The obtained results are inconsistent with Government and Binding, but consistent with the latter two theories. We further show that the Primitives of Binding framework most naturally explains our results. Our proposal is based on the different performance demonstrated by patients in transitive clauses and ECM constructions, in combination with the often-made claim in the literature regarding the limitation of processing resources in this population (e.g., Haarmann and Kolk, 1991, Haarmann and Kolk, 1994 and Zurif et al., 1993, among others).

Obviation in Subjunctive Clauses and AGR: Evidence from Russian

Subjunctive clauses of many Romance and Slavic languages show subject obviation phenomena; that is, the requirement that a pronominal subject of a subjunctive clause be disjoint in reference from the matrix subject. Most of the previous explanations of the phenomenon stipulated that the anaphoric nature of subjunctive Tense leads to an extension of the binding domain of the subject pronoun to include the matrix clause, thus leading to the pronoun being locally bound in violation of Principle B. Using evidence from Russian, we show that the domain extension approaches cannot be correct. We argue for an analysis in which the subjunctive Complementizer is an operator which moves at LF to bind the events of the matrix and the subjunctive clauses. The resulting configuration creates a violation of Principle B with respect to the subjunctive AgrS which is coindexed with the subjunctive subject. Our approach can explain all of the known facts and makes strong cross-linguistic predictionsthat we show to be correct.

Interpretation of pronouns in VP-ellipsis constructions in Dutch Broca’s and Wernicke’s aphasia

In this paper, we investigate the ability of Dutch agrammatic Brocas and Wernickes aphasics to assign reference to possessive pronouns in elided VP constructions. The assumption is that the comprehension problems in these two populations have different sources that are revealed in distinct patterns of responses. The focus is primarily on the performance of the agrammatic group whose errors in comprehension are not viewed as a consequence of a breakdown of grammatical knowledge but as a result of limited processing resources (for an overview see Grodzinsky, 2000). The results of the present study provide evidence for the psycholinguistic reality of the economy hierarchy as proposed in the Primitives of Binding (Reuland, 2001). According to the economy hierarchy proposed for the non-brain-damaged, the more economical semantic dependencies are preferred over the costlier discourse dependencies. This hierarchy is reflected in agrammatic aphasia where the semantic dependencies are available on time and preferred over the discourse dependences that are not available on time as a result of the lack of processing resources with consequences for comprehension.

Article omission in Dutch children with SLI: A Processing Approach.

Children with Specific Language Impairment (SLI) show difficulties with grammatical morphology. Based on the data from 12 Dutch children with SLI, an information-theoretical model is proposed in which the noun-article set dependency is modeled as a channel. We propose that reduced capacity of this channel is responsible for article omission. The Kullback-Leibler divergence between input and output distribution of article production provides an index of the channel capacity, which is shown to correlate with the percentage of article omission and to lag behind in SLI development as compared to typically developing children.

Zipf’s Law in Non-Fluent Aphasia

Abstract We studied Zipf’s law in the spontaneous speech of four people with non-fluent aphasia, and compared that to the spontaneous speech of four speakers from the Corpus of Spoken Dutch. Our results show no worse fit to Zipf’s law for aphasic compared to healthy speech but only a difference in slope. We argue that the fact that Zipf’s law is unaffected in people with aphasia, who suffer from problems with word retrieval rather than word storage, suggests that it is the organization of the mental lexicon that renders speech to conform to Zipf’s law and not the word retrieval system.

Zipf's Law in Aphasia Across Languages: A Comparison of English, Hungarian and Greek

Abstract We investigated Zipf’s law in fluent and non-fluent aphasics’ spontaneous speech in English, Hungarian, and Greek. A previous study showed that the word frequency distribution in Dutch non-fluent aphasic speech conforms to Zipf’s law, although with a different slope. In this project we investigated to what extent these results can be generalized to other languages and to fluent aphasic speech. The results suggest that both the fluent and the non-fluent aphasic speech of English, Hungarian and Greek conform to Zipf’s law, and that differences in slope can be related to a language’s morphological properties and a group’s particular language impairments.

The Influence of Texting Language on Grammar and Executive Functions in Primary School Children

When sending text messages on their mobile phone to friends, children often use a special type of register, which is called textese. This register allows the omission of words and the use of textisms: instances of non-standard written language such as 4ever (forever). Previous studies have shown that textese has a positive effect on children’s literacy abilities. In addition, it is possible that children’s grammar system is affected by textese as well, as grammar rules are often transgressed in this register. Therefore, the main aim of this study was to investigate whether the use of textese influences children’s grammar performance, and whether this effect is specific to grammar or language in general. Additionally, studies have not yet investigated the influence of textese on children’s cognitive abilities. Consequently, the secondary aim of this study was to find out whether textese affects children’s executive functions. To investigate this, 55 children between 10 and 13 years old were tested on a receptive vocabulary and grammar performance (sentence repetition) task and various tasks measuring executive functioning. In addition, text messages were elicited and the number of omissions and textisms in children’s messages were calculated. Regression analyses showed that omissions were a significant predictor of children’s grammar performance after various other variables were controlled for: the more words children omitted in their text messages, the better their performance on the grammar task. Although textisms correlated (marginally) significantly with vocabulary, grammar and selective attention scores and omissions marginally significantly with vocabulary scores, no other significant effects were obtained for measures of textese in the regression analyses: neither for the language outcomes, nor for the executive function tasks. Hence, our results show that textese is positively related to children’s grammar performance. On the other hand, use of textese does not affect—positively nor negatively—children’s executive functions.

Register affects language comprehension: ERP evidence from article omission in newspaper headlines

Abstract Language processing involving syntax-discourse interface operations has been claimed to be particularly resource-consuming. In production, this additional complexity is claimed to be the source of article omission in the speech of young children and certain language-impaired speakers. In comprehension, article omission in some “special registers” (e.g., newspaper headlines) has been attributed to the trade-off between spending more processing resources and increasing processing speed. We investigated the comprehension of noun phrases (NPs) with and without articles (e.g., (a) policeman arrests (a) monk) when readers were or were not aware of reading headlines by recording electrophysiological responses. The presence of an N400-effect suggests first that comprehension of article-less NPs exerts processing demands and indicates that article omission does not result in costs from morphosyntactic processing (no LAN), but from linking processes at the syntax-discourse interface supported by discourse-semantic memory. Differences between the instruction modalities suggest that awareness of the special register plays a role. The electrophysiological data thus demonstrate that register has an effect on the discourse-semantic integration of NPs and provide evidence for a certain degree of top-down processing.