Acquisition and Representation of Grammatical Categories: Grammatical Gender in a Connectionist Network

In traditional models of language production grammatical categories are represented as abstract features independent of semantics and phonology. An alternative view is proposed where syntactic categories emerge as a higher-order regularity from semantic and phonological properties of words. The proposal was tested using grammatical gender in Serbian, a south Slavic language with rich morphology. Semantic and phonological correlates of gender are described using a corpus of 1221 Serbian nouns. A PDP network was trained to produce the same words based on distributed semantic representation as input and distributed phonological representation as output, and with no explicit representation of grammatical gender. Upon successful learning of the training corpus, generalization was explored using test corpora designed to capture semantic and phonological properties of different genders. The findings suggest that grammatical gender, as other syntactic categories, may be viewed as emerging through coherent co-variation of semantic and phonological properties of words during learning

Impact of dialect use on a basic component of learning to read

Can some black-white differences in reading achievement be traced to differences in language background? Many African American children speak a dialect that differs from the mainstream dialect emphasized in school. We examined how use of alternative dialects affects decoding, an important component of early reading and marker of reading development. Behavioral data show that use of the alternative pronunciations of words in different dialects affects reading aloud in developing readers, with larger effects for children who use more African American English. Mechanisms underlying this effect were explored with a computational model, investigating factors affecting reading acquisition. The results indicate that the achievement gap may be due in part to differences in task complexity: children whose home and school dialects differ are at greater risk for reading difficulties because tasks such as learning to decode are more complex for them

Semantic indeterminacy in object relative clauses

This article examined whether semantic indeterminacy plays a role in comprehension of complex structures such as object relative clauses. Study 1 used a gated sentence completion task to assess which alternative interpretations are dominant as the relative clause unfolds; Study 2 compared reading times in object relative clauses containing different animacy configurations to unambiguous passive controls; and Study 3 related completion data and reading data. The results showed that comprehension difficulty was modulated by animacy configuration and voice (active vs. passive). These differences were well correlated with the availability of alternative interpretations as the relative clause unfolds, as revealed by the completion data. In contrast to approaches arguing that comprehension difficulty stems from syntactic complexity, these results suggest that semantic indeterminacy is a major source of comprehension difficulty in object relative clauses. Results are consistent with constraint-based approaches to ambiguity resolution and bring new insights into previously identified sources of difficulty. (C) 2007 Elsevier Inc. All rights reserved

How language production shapes language form and comprehension

Language production processes can provide insight into how language comprehension works and language typology—why languages tend to have certain characteristics more often than others. Drawing on work in memory retrieval, motor planning, and serial order in action planning, the Production-Distribution-Comprehension (PDC) account links work in the fields of language production, typology, and comprehension: 1) faced with substantial computational burdens of planning and producing utterances, language producers implicitly follow three biases in utterance planning that promote word order choices that reduce these burdens, thereby improving production fluency. 2) These choices, repeated over many utterances and individuals, shape the distributions of utterance forms in language. The claim that language form stems in large degree from producers’ attempts to mitigate utterance planning difficulty is contrasted with alternative accounts in which form is driven by language use more broadly, language acquisition processes, or producers’ attempts to create language forms that are easily understood by comprehenders. 3) Language perceivers implicitly learn the statistical regularities in their linguistic input, and they use this prior experience to guide comprehension of subsequent language. In particular, they learn to predict the sequential structure of linguistic signals, based on the statistics of previously-encountered input. Thus key aspects of comprehension behavior are tied to lexico-syntactic statistics in the language, which in turn derive from utterance planning biases promoting production of comparatively easy utterance forms over more difficult ones. This approach contrasts with classic theories in which comprehension behaviors are attributed to innate design features of the language comprehension system and associated working memory. The PDC instead links basic features of comprehension to a different source: production processes that shape language form

Visual salience modulates structure choice in relative clause production. Lang. Speech Advance online publication

Abstract The role of visual salience on utterance form was investigated in a picture description study. Participants heard spoken questions about animate or inanimate entities in a picture and produced a relative clause in response. Visual properties of the scenes affected production choices such that less salient inanimate entities tended to yield longer initiation latencies and to be described with passive relative clauses more than visually salient inanimates. We suggest that the participants' question-answering task can change as a function of visual salience of entities in the picture. Less salient entities require a longer visual search of the scene, which causes the speaker to notice or attend more to the non-target competitors in the picture. As a result, it becomes more important in answering the question for the speaker to contrast the target item with a salient competitor. This effect is different from other effects of visual salience, which tend to find that more salient entities take more prominent grammatical roles in the sentence. We interpret this discrepancy as evidence that visual salience does not have a single effect on sentence production, but rather its effect is modulated by task and linguistic context

Experience and generalization in a connectionist model of Mandarin Chinese relative clause processing

Sentences containing relative clauses are well known to be difficult to comprehend, and they have long been an arena in which to investigate the role of working memory in language comprehension. However, recent work has suggested that relative clause processing is better described by ambiguity resolution processes than by limits on extrinsic working memory. We investigated these alternative views with a Simple Recurrent Network (SRN) model of relative clause processing in Mandarin Chinese, which has a unique pattern of word order across main and relative clauses and which has yielded mixed results in human comprehension studies. To assess the model's ability to generalize from similar sentence structures, and to observe effects of ambiguity through the sentence, we trained the model on several different sentence types, based on a detailed corpus analysis of Mandarin relative clauses and simple sentences, coded to include patterns of noun animacy in the various structures. The model was evaluated on 16 different relative clause subtypes. Its performance corresponded well to human reading times, including effects previously attributed to working memory overflow. The model's performance across a wide variety of sentence types suggested that the seemingly inconsistent results in some prior empirical studies stemmed from failures to consider the full range of sentence types in empirical studies. Crucially, sentence difficulty for the model was not simply a reflection of sentence frequency in the training set; the model generalized from similar sentences and showed high error rates at points of ambiguity. The results suggest that SRNs are a powerful tool to examine the complicated constraint-satisfaction process of sentence comprehension, and that understanding comprehension of specific structures must include consideration of experiences with other similar structures in the language