Unsupervised syntactic chunking with acoustic cues: Computational models for prosodic bootstrapping

Learning to group words into phrases without supervision is a hard task for NLP systems, but infants routinely accomplish it. We hypothesize that infants use acoustic cues to prosody, which NLP systems typically ignore. To evaluate the utility of prosodic information for phrase discovery, we present an HMM-based unsupervised chunker that learns from only transcribed words and raw acoustic correlates to prosody. Unlike previous work on unsupervised parsing and chunking, we use neither gold standard part-of-speech tags nor punctuation in the input. Evaluated on the Switchboard corpus, our model outperforms several baselines that exploit either lexical or prosodic information alone, and, despite producing a flat structure, performs competitively with a state-of-the-art unsupervised lexicalized parser, with a substantial advantage in precision. Our results support the hypothesis that acoustic-prosodic cues provide useful evidence about syntactic phrases for language-learning infants.10 page(s

Differential effects of internal and external factors on the development of vocabulary, tense morphology and morpho-syntax in successive bilingual children

The present study investigates the effects of child internal (age/time) and child external/environmental factors on the development of a wide range of language domains in successive bilingual (L2) Turkish-English children of homogeneously low SES. Forty-three L2 children were tested on standardized assessments examining the acquisition of vocabulary and morpho-syntax. The L2 children exhibited a differential acquisition of the various domains: they were better on the general comprehension of grammar and tense morphology and less accurate on the acquisition of vocabulary and (complex) morpho-syntax. Profile effects were confirmed by the differential effects of internal and external factors on the language domains. The development of vocabulary and complex syntax were affected by internal and external factors, whereas external factors had no contribution to the development of tense morphology. These results are discussed in light of previous studies on the impact of internal and external factors in child L2 acquisition

Common aetiology for diverse language skills in 41/2-year-old twins

Multivariate genetic analysis was used to examine the genetic and environmental aetiology of the interrelationships of diverse linguistic skills. This study used data from a large sample of 4 1/2 year-old twins who were tested on measures assessing articulation, phonology, grammar, vocabulary, and verbal memory. Phenotypic analysis suggested two latent factors: articulation (2 measures) and general language (the remaining 7), and a genetic model incorporating these factors provided a good fit to the data. Almost all genetic and shared environmental influences on the 9 measures acted through the two latent factors. There was also substantial aetiological overlap between the two latent factors, with a genetic correlation of 0·64 and shared environment correlation of 1·00. We conclude that to a large extent, the same genetic and environmental factors underlie the development of individual differences in a wide range of linguistic skills

On the nature and cause of Specific Language Impairment: a view from sentence processing and infant research

This paper addresses the nature and cause of Specific Language Impairment (SLI) by reviewing recent research in sentence processing of children with SLI compared to typically developing (TD) children and research in infant speech perception. These studies have revealed that children with SLI are sensitive to syntactic, semantic, and real-world information, but do not show sensitivity to grammatical morphemes with low phonetic saliency, and they show longer reaction times than age-matched controls. TD children from the age of 4 show trace reactivation, but some children with SLI fail to show this effect, which resembles the pattern of adults and TD children with low working memory. Finally, findings from the German Language Development (GLAD) Project have revealed that a group of children at risk for SLI had a history of an auditory delay and impaired processing of prosodic information in the first months of their life, which is not detectable later in life. Although this is a single project that needs to be replicated with a larger group of children, it provides preliminary support for accounts of SLI which make an explicit link between an early deficit in the processing of phonology and later language deficits, and the Computational Complexity Hypothesis that argues that the language deficit in children with SLI lies in difficulties integrating different types of information at the interfaces

On Morpho-Syntax

This short paper offers a moment of reflection on the state of the Generative Grammar enterprise especially in light of the fact the Minimalist Syntax has so completely returned to a mission that includes (rather than explicitly excludes) a model of word-formation. I focus here on a discussion of crucial ways the move from "syntactic" theory to "morphosyntactic" theory has changed the mission of generative grammar and to what extent practitioners have kept pace. I hope to provide both a broad and a long view of metatheoretic concerns we now find ourselves at the nexus of and suggest best practices in light of those views.Aquest article breu ofereix un moment de reflexió sobre l'estat de l'empresa gramatical generativa, sobretot a la vista que la sintaxi minimalista ha tornat de manera tan completa a una missió que inclou (més que no pas exclou explícitament) un model de formació de paraules. Em centro aquí en una discussió de maneres crucials de passar de la teoria "sintàctica" a la teoria "morfosintàctica " que ha canviat la missió de la gramàtica generativa i fins a quin punt els practicants han mantingut el ritme. Espero oferir una visió àmplia i llarga de les preocupacions metateorètiques que ara ens trobem en el punt de mira i suggerir bones pràctiques a la vista d'aquestes opinions

Cyclicity and prosody in Armenian stress-assignment

The morphology-phonology interface is rife with examples of interactions between the two modules. Various theoretical models have been proposed to either a) cover the entire interface, or b) cover a subset of this interface. Lexical Phonology and Prosodic Phonology are two popular models of how this interface operates. However it is an open question if both models are needed and if one can do the job of the other. In this paper, data from Armenian morpho-phonology shows the need for both models to be combined and used as one single model for the interface. Crucially, data on Armenian stress assignment and destressed vowel reduction necesitates using both Lexical Phonology\u27s concepts of cyclicity and strata and Prosodic Phonology\u27s concepts of prosodic stems and prosodic non-isomorphism

Recursive and non-recursive tone sandhi domains in Laoling trisyllabic sequences

In previous studies, variations of tone sandhi domains of tri-tonal sequences are either recursive or non-recursive domains, differing only in prosodic branching. In Laoling, however, both recursive, e.g., (σ(σσ)), ((σσ)σ), and non-recursive variant domains, e.g., (σ)(σσ), (σσ)(σ), are observed. In traditional Optimality Theory (Prince & Smolensky 1993), such variations cannot be predicted. In this study, we combine Coetzee’s (2006) Rank-Ordering model of Eval with McCarthy’s (2010) Harmonic Serialism and demonstrate how both recursive and non-recursive domains and their varying frequencies can be predicted

Dialectal variation in german 3-verb clusters : a surface-oriented optimality theoretic account

We present data from an empirical investigation on the dialectal variation in the syntax of German 3-verb clusters, consisting of a temporal auxiliary, a modal verb, and a predicative verb. The ordering possibilities vary greatly among the dialects. Some of the orders that we found occur only under particular stress assignments. We assume that these orders fulfil an information structural purpose and that the reordering processes are changes only in the linear order of the elements which is represented exclusively at the surface syntactic level, PF (Phonetic Form). Our Optimality theoretic account offers a multifactorial perspective on the phenomenon