Distributional structure in language: contributions to noun-verb difficulty differences in infant word recognition

The distributional and embodied contexts of verbs in caregiver-infant interactions

The process by which infants learn verbs through daily social interactions is not well-understood. This study investigated caregivers' use of verbs, which have highly abstract meanings, during unscripted toy-play. We examined how verbs co-occurred with distributional and embodied factors including pronouns, caregivers' manual actions, and infants' locomotion, gaze, and object-touching. Object-action verbs were used significantly more often during caregiver-infant joint attention interactions. Movement and cognition verbs showed distinct co-occurrences with different contexts. Cognition and volition verbs were differentiated by pronouns. These findings provide evidence for how verb acquisition may be supported by the distributional and embodied contexts in caregiver-infant interactions.

6-month-olds are sensitive to English morphology

Each language has its unique way to mark grammatical information such as gender, number and tense. For example, English marks number and tense/aspect information with morphological suffixes (e.g., -s or -ed). These morphological suffixes are crucial for language acquisition as they are the basic building blocks of syntax, encode relationships, and convey meaning. Previous research shows that English-learning infants recognize morphological suffixes attached to nonce words by the end of the first year, although even 8-month-olds recognize them when they are attached to known words. These results support an acquisition trajectory where discovery of meaning guides infants' acquisition of morphological suffixes. In this paper, we re-evaluated English-learning infants' knowledge of morphological suffixes in the first year of life. We found that 6-month-olds successfully segmented nonce words suffixed with -s, -ing, -ed and a pseudo-morpheme -sh. Additionally, they related nonce words suffixed with -s, but not -ing, -ed or a pseudo-morpheme -sh and stems. By 8-months, infants were also able to relate nonce words suffixed with -ing and stems. Our results show that infants demonstrate knowledge of morphological relatedness from the earliest stages of acquisition. They do so even in the absence of access to meaning. Based on these results, we argue for a developmental timeline where the acquisition of morphology is, at least, concurrent with the acquisition of phonology and meaning.

Stem similarity modulates infants' acquisition of phonological alternations

Phonemes have variant pronunciations depending on context. For instance, in American English, the [t] in pat [pæt] and the [d] in pad [pæd] are both realized with a tap [ɾ] when the -ing suffix is attached, [pæɾɪŋ]. We show that despite greater distributional and acoustic support for the [t]-tap alternation, 12-month-olds successfully relate taps to stems with a perceptually-similar final [d], not the dissimilar final-[t]. Thus, distributional learning of phonological alternations is constrained by infants' preference for the alternation of perceptually-similar segments. Further, the ability to relate variant surface forms emerges between 8- and 12-months. Our findings of biased learning provide further empirical support for a role for perceptual similarity in the acquisition of linguistically-relevant categories. We discuss the implications of our findings for phonological theory, language acquisition and models of the mental lexicon.

Verbal Working Memory as Emergent from Language Comprehension and Production

This article reviews current models of verbal working memory and considers the role of language comprehension and long-term memory in the ability to maintain and order verbal information for short periods of time. While all models of verbal working memory posit some interaction with long-term memory, few have considered the character of these long-term representations or how they might affect performance on verbal working memory tasks. Similarly, few models have considered how comprehension processes and production processes might affect performance in verbal working memory tasks. Modern theories of comprehension emphasize that people learn a vast web of correlated information about the language and the world and must activate that information from long-term memory to cope with the demands of language input. To date, there has been little consideration in theories of verbal working memory for how this rich input from comprehension would affect the nature of temporary memory. There has also been relatively little attention to the degree to which language production processes naturally manage serial order of verbal information. The authors argue for an emergent model of verbal working memory supported by a rich, distributed long-term memory for language. On this view, comprehension processes provide encoding in verbal working memory tasks, and production processes maintenance, serial ordering, and recall. Moreover, the computational capacity to maintain and order information varies with language experience. Implications for theories of working memory, comprehension, and production are considered.

ProtFus: A Comprehensive Method Characterizing Protein-Protein Interactions of Fusion Proteins

Tailored therapy aims to cure cancer patients effectively and safely, based on the complex interactions between patients' genomic features, disease pathology and drug metabolism. Thus, the continual increase in scientific literature drives the need for efficient methods of data mining to improve the extraction of useful information from texts based on patients' genomic features. An important application of text mining to tailored therapy in cancer encompasses the use of mutations and cancer fusion genes as moieties that change patients' cellular networks to develop cancer, and also affect drug metabolism. Fusion proteins, which are derived from the slippage of two parental genes, are produced in cancer by chromosomal aberrations and trans-splicing. Given that the two parental proteins for predicted fusion proteins are known, we used our previously developed method for identifying chimeric protein-protein interactions (ChiPPIs) associated with the fusion proteins. Here, we present a validation approach that receives fusion proteins of interest, predicts their cellular network alterations by ChiPPI and validates them by our new method, ProtFus, using an online literature search. This process resulted in a set of 358 fusion proteins and their corresponding protein interactions, as a training set for a Naïve Bayes classifier, to identify predicted fusion proteins that have reliable evidence in the literature and that were confirmed experimentally. Next, for a test group of 1817 fusion proteins, we were able to identify from the literature 2908 PPIs in total, across 18 cancer types. The described method, ProtFus, can be used for screening the literature to identify unique cases of fusion proteins and their PPIs, as means of studying alterations of protein networks in cancers. Availability: http://protfus.md.biu.ac.il/.

Experience with morphosyntactic paradigms allows toddlers to tacitly anticipate overregularized verb forms months before they produce them

When do children acquire abstract grammatical categories? Studies of 2- to 3-year-olds' productions of complete morphosyntactic paradigms (e.g., all legal determiners with all nouns) suggest relatively later category acquisition, while studies of infant discrimination of grammatical vs. ungrammatical sequences suggest earlier acquisition. However, few of the latter studies have probed category generalization by examining how learners treat gaps in their input, and none have found evidence that learners before the age of 2 years fill gaps in verb paradigms. Therefore, the three experiments presented here asked whether 16-month-olds tacitly expect to hear forms like breaked by presenting them with overregularized verbs vs. (1) nonce verbs + -ed, (2) real English nouns + -ed, and (3) the correct irregular counterparts. The pattern of listening preferences suggests that toddlers anticipate overregularized forms, suggesting that they have a general proto-category verb, to which they expect the complete set of verb inflections to apply.

SparkText: Biomedical Text Mining on Big Data Framework

Background

Many new biomedical research articles are published every day, accumulating rich information, such as genetic variants, genes, diseases, and treatments. Rapid yet accurate text mining on large-scale scientific literature can discover novel knowledge to better understand human diseases and to improve the quality of disease diagnosis, prevention, and treatment.

Results

In this study, we designed and developed an efficient text mining framework called SparkText on a Big Data infrastructure, which is composed of Apache Spark data streaming and machine learning methods, combined with a Cassandra NoSQL database. To demonstrate its performance for classifying cancer types, we extracted information (e.g., breast, prostate, and lung cancers) from tens of thousands of articles downloaded from PubMed, and then employed Naïve Bayes, Support Vector Machine (SVM), and Logistic Regression to build prediction models to mine the articles. The accuracy of predicting a cancer type by SVM using the 29,437 full-text articles was 93.81%. While competing text-mining tools took more than 11 hours, SparkText mined the dataset in approximately 6 minutes.

Conclusions

This study demonstrates the potential for mining large-scale scientific articles on a Big Data infrastructure, with real-time update from new articles published daily. SparkText can be extended to other areas of biomedical research.

Sounds and meanings working together: Word learning as a collaborative effort

Over the past several decades, researchers have discovered a great deal of information about the processes underlying language acquisition. From as early as they can be studied, infants are sensitive to the nuances of native-language sound structure. Similarly, infants are attuned to the visual and conceptual structure of their environments starting in the early postnatal period. Months later, they become adept at putting these two arenas of experience together, mapping sounds to meanings. How might learning sounds influence learning meanings, and vice versa? In this paper, I will describe several recent lines of research suggesting that knowledge concerning the sound structure of language facilitates subsequent mapping of sounds to meanings. I will also discuss recent findings suggesting that from its beginnings, the lexicon incorporates relationships amongst the sounds and meanings of newly learned words.