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Aphasia is a disability of language processing often suffered by people as a result of a stroke or head injury. In order to assist aphasic readers we are developing a system which automatically simplifies English newspaper texts as available on the Internet. The system combines state-of-the-art natural language processing tools with innovative research on text simplification. We present the architecture of the system, discuss the analysis of newspaper text and a number of criteria for simplification. In addition, we provide some initial implementation details and propose an evaluation method. Keywords: robust parsing, text simplification, aphasia, reading assistance Introduction Recently, there has been increasing interest in the use of results from natural language processing for the development of assistive technology. 1 Here, we address this topic by reporting preliminary work carried out in the research project "PSET: Practical Simplification of English Text". 2 The aim of t...

Selective deficits in aphasics patients ’ grammatical production and comprehension are often cited as evidence that syntactic processing is modular and localizable in discrete areas of the brain (e.g., Y. Grodzinsky, 2000). The authors review a large body of experimental evidence suggesting that morphosyntactic deficits can be observed in a number of aphasic and neurologically intact populations. They present new data showing that receptive agrammatism is found not only over a range of aphasic groups, but is also observed in neurologically intact individuals processing under stressful conditions. The authors suggest that these data are most compatible with a domain-general account of language, one that emphasizes the interaction of linguistic distributions with the properties of an associative processor working under normal or suboptimal conditions. The primary purpose of this article is to provide empirical arguments in support of a new view of language deficits and their neural correlates, particularly in the realm of syntax. Selective syntactic deficits are often cited as evidence that the human brain contains a bounded and well-defined faculty or module dedicated exclusively to the representation and/or processing of syntax (Caplan & Waters, 1999; Grodzinsky, 1995a,

“Origins of communicative disorders ” to Elizabeth Bates, and by a grant from the John D. and Catherine T. MacArthur Foundation. We are grateful to Larry Juarez and Meiti Opie The effects of focal brain injury are investigated in the first stages of language development, during the passage from first words to grammar. Parent report and/or free speech data are reported for 53 infants and preschool children between 10- 44 months of age. All children had suffered a single, unilateral brain injury to the left or right hemisphere, incurred before six months of age (usually in the pre- or perinatal period). This is the period in which we should expect to see maximal plasticity, but it is also the period in which the initial specializations of particular cortical regions ought to be most evident. In direct contradiction of hypotheses based on the adult aphasia literature, results from 10- 17 months suggest that children with righthemisphere injuries are at greater risk for delays in word comprehension, and in the gestures that normally precede and accompany language onset. Although there were no differences between left- vs. right-hemisphere injury per se on expressive language, children whose lesions include the left temporal lobe did show significantly greater delays in expressive vocabulary and

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M. A. Just and P. A. Carpenter’s (1992) capacity theory of comprehension posits a linguistic working memory functionally separated from the representation of linguistic knowledge. G. S. Waters and D. Caplan’s (1996) critique of this approach retained the notion of a separate working memory. In this article, the authors present an alternative account motivated by a connectionist approach to language comprehension. In their view, processing capacity emerges from network architecture and experience and is not a primitive that can vary independently. Individual differences in comprehension do not stem from variations in a separate working memory capacity; instead they emerge from an interaction of biological factors and language experience. This alternative is argued to provide a superior account of comprehension results previously attributed to a separate working memory capacity. The concept of a working memory resource or capacity for temporary storage and manipulation of information has played an important role in many theories of cognition, particularly theories of language processing (e.g., Baddeley, 1986; Engle, Cantor, &

I will be investigating the notion that the acquisition of syntax is a two-stage process: 1) the contents and structure of the lexicon are learned through a statistical inductive procedure; and 2) a deductive, rule-based procedure, examining the contents of this lexicon, allows the child to make syntactic generalizations. Using these tools, along with the assumption that the child learns thematic words (nouns, verbs, adjectives) and function words (prepositions, auxiliaries, inflection) in different ways, I have been able to construct a model of early language acquisition: Babel. Simulations using Babel are shown to make predictions about the time course of acquisition across languages which are highly correlated with longitudinal studies of early child language. 1 Introduction The model of lexical and syntactic acquisition which I will describe here is intended to be a computationally, psychologically and empirically accurate reflection of the acquisition of the lexicon and of syntax...

The Competition Model is an interactive-activation framework for the study of sentence processing that is designed to handle quantitative as well as qualitative variations in performance across natural languages. Previous studies within this framework have shown that adult listeners base their interpretation of simple sentences on the most valid and reliable cues in their language (e.g. more use of word order in English and more use of subject– verb agreement in Italian). Critics have argued that such effects may re�ect heuristics that are only applied to simple sentences. The present study shows that these cross-linguistic differences are maintained when participants are asked to interpret complex sentences with an embedded relative clause. A comparison of ‘‘off-line’ ’ (untimed) and ‘‘on-line’ ’ (timed) versions of the same experiments shows that these effects hold up under time pressure. The on-line versions also provide new information about cross-linguistic differences in timing and demands on processing. In particular, the processing costs associated with centre embedding and non-canonical order are greater in English, which may be the price that English listeners have to pay for heavy reliance on word order information.

Although widespread neural atrophy is an inevitable consequence of normal aging, not all cognitive abilities decline as we age. For example, spoken language comprehension tends to be preserved, despite atrophy in neural regions involved in language function. Here, we combined measures of behavior, functional activation, and gray matter (GM) change in a younger (19--34 years) and older group (49--86 years) of participants to identify the mechanisms leading to preserved language comprehension across the adult life span. We focussed primarily on syntactic functions because these are strongly left lateralized, providing the potential for contralateral recruitment. In an functional magnetic resonance imaging study, we used a word-monitoring task to minimize working memory demands, manipulating the availability of semantics and syntax to ask whether syntax is preserved in aging because of the functional recruitment of other brain regions, which successfully compensate for neural atrophy. Performance in the older group was preserved despite GM loss. This preservation was related to increased activity in right hemisphere frontotemporal regions, which was associated with age-related atrophy in the left hemisphere frontotemporal network activated in the young. We argue that preserved syntactic processing across the life span is due to the shift from a primarily left hemisphere frontotemporal system to a bilateral functional language network.

. This paper describes the theory and implementation of Babel, a system which explores the hypothesis that much of the differences in the world's languages may be characterized by the inventory and properties of the lexical items and functional categories of those languages. The structure of Babel assumes that functional categories are originally lacking in a child's syntax, and are acquired through a statistical induction process of lexical acquisition. Babel then uses information induced from the structure of the lexicon to create a model of syntax via a deductive, rule-based process. This model makes a number of predictions about the time course of language acquisition. These predictions are tested by running Babel as a simulation of child language acquisition, using large samples of adult speech to children as input. The simulation results are shown to highly correlate to longitudinal studies of child language acquisition in English and Polish. Finally, the approach to handling noi...