Word graphs: The third set

This is the third paper in a series of natural language processing in term of knowledge graphs. A word is a basic unit in natural language processing. This is why we study word graphs. Word graphs were already built for prepositions and adwords (including adjectives, adverbs and Chinese quantity words) in two other papers. In this paper, we propose the concept of the logic word and classify logic words into groups in terms of semantics and the way they are used in describing reasoning processes. A start is made with the building of the lexicon of logic words in terms of knowledge graphs

Morphologically complex words in L1 and L2 processing: Evidence from masked priming experiments in English

This paper reports results from masked priming experiments investigating regular past-tense forms and deadjectival nominalizations with -ness and -ity in adult native (L1) speakers of English and in different groups of advanced adult second language (L2) learners of English. While the L1 group showed efficient priming for both inflected and derived word forms, the L2 learners demonstrated repetition-priming effects (like the L1 group), but no priming for inflected and reduced priming for derived word forms. We argue that this striking contrast between L1 and L2 processing supports the view that adult L2 learners rely more on lexical storage and less on combinatorial processing of morphologically complex words than native speakers.</jats:p

Children's naming and word-finding difficulties: descriptions and explanations

Purpose: There are a substantial minority of children for whom lexical retrieval problems impede the normal pattern of language development and use. These problems include accurately producing the correct word even when the word?s meaning is understood; such children are often referred to as having word-finding difficulties (WFDs). This review examines the nature of naming and lexical retrieval difficulties in these and other groups of children. Method: A review of the relevant literature on lexical access difficulties in children with word finding difficulties was conducted. Studies were examined in the terms of population parameters and comparison groups included in the study. Results and Conclusions: Most discussions of the cognitive processes causing lexical retrieval difficulties have referred to semantics, phonology and processing speed. It is argued that our understanding of these topics will be further advanced by the use of appropriate methodology to test developmental models that both identify the processes in successfully performing different lexical retrieval tasks and more precisely locating the difficulties experienced by children with such tasks

Spatial attention shifting and phonological processing in adults with dyslexia

According to Hari and Renvall’s (2001) sluggish attentional shifting (SAS) hypothesis people with dyslexia have a central deficit in attention shifting. Here we assessed whether a group of adults with dyslexia showed impaired performance on shifting visual spatial attention. Twelve adults with dyslexia and 12 control adult participants took part in a Posner style focused attention orientation task and a shift attention orientation task. The participants also completed standardized measures of single word reading, spelling, IQ, phonological processing, speed of processing and non-word reading. Overall, the dyslexic participants showed the same pattern of performance as the control participants on the attention-orienting task, but completed the tasks at a consistently slower pace. Specifically, participants in both groups found short target presentation intervals more difficult than longer target presentation intervals, and participants in both groups were more impaired when cue-to-target information was invalid 20% of the time (shift task) than when it was valid all of the time (focused task). However, the group with dyslexia was significantly more impaired across the board

Automatic memory processes in normal ageing and Alzheimer’s disease

This study examined the contribution of automatic and controlled uses of memory to stem completion in young, middle-aged and older adults, and compared these data with a study involving patients with Alzheimer’s disease (AD) who performed the same task (Hudson and Robertson, 2007). In an inclusion task participants aimed to complete three-letter word stems with a previously studied word, in an exclusion task the aim was to avoid using studied words to complete stems. Performances under inclusion and exclusion conditions were contrasted to obtain estimates of controlled and automatic memory processes using process-dissociation calculations (Jacoby, 1991). An age-related decline, evident from middle age was observed for the estimate of controlled processing, whereas the estimate of automatic processing remained invariant across the age groups. This pattern stands in contrast to what is observed in AD, where both controlled and automatic processes have been shown to be impaired. Therefore, the impairment in memory processing on stem completion that is found in AD is qualitatively different from that observed in normal ageing

Evaluating Feature Extraction Methods for Biomedical Word Sense Disambiguation

Evaluating Feature Extraction Methods for Biomedical WSD Clint Cuffy, Sam Henry and Bridget McInnes, PhD Virginia Commonwealth University, Richmond, Virginia, USA Introduction. Biomedical text processing is currently a high active research area but ambiguity is still a barrier to the processing and understanding of these documents. Many word sense disambiguation (WSD) approaches represent instances of an ambiguous word as a distributional context vector. One problem with using these vectors is noise -- information that is overly general and does not contribute to the word’s representation. Feature extraction approaches attempt to compensate for sparsity and reduce noise by transforming the data from high-dimensional space to a space of fewer dimensions. Currently, word embeddings [1] have become an increasingly popular method to reduce the dimensionality of vector representations. In this work, we evaluate word embeddings in a knowledge-based word sense disambiguation method. Methods. Context requiring disambiguation consists of an instance of an ambiguous word, and multiple denotative senses. In our method, each word is replaced with its respective word embedding and either summed or averaged to form a single instance vector representation. This also is performed for each sense of an ambiguous word using the sense’s definition obtained from the Unified Medical Language System (UMLS). We calculate the cosine similarity between each sense and instance vectors, and assign the instance the sense with the highest value. Evaluation. We evaluate our method on three biomedical WSD datasets: NLM-WSD, MSH-WSD and Abbrev. The word embeddings were trained on the titles and abstracts from the 2016 Medline baseline. We compare using two word embedding models, Skip-gram and Continuous Bag of Words (CBOW), and vary the word vector representational lengths, from one-hundred to one-thousand, and compare differences in accuracy. Results. The overall outcome of this method demonstrates fairly high accuracy at disambiguating biomedical instance context from groups of denotative senses. The results showed the Skip-gram model obtained a higher disambiguation accuracy than CBOW but the increase was not significant for all of the datasets. Similarly, vector representations of differing lengths displayed minimal change in results, often differing by mere tenths in percentage. We also compared our results to current state-of-the-art knowledge-based WSD systems, including those that have used word embeddings, showing comparable or higher disambiguation accuracy. Conclusion. Although biomedical literature can be ambiguous, our knowledge-based feature extraction method using word embeddings demonstrates a high accuracy in disambiguating biomedical text while eliminating variations of associated noise. In the future, we plan to explore additional dimensionality reduction methods and training data. [1] T. Mikolov, I. Sutskever, K. Chen, G. Corrado and J. Dean, Distributed representations of words and phrases and their compositionality, Advances in neural information processing systems, pp. 3111-3119, 2013.https://scholarscompass.vcu.edu/uresposters/1278/thumbnail.jp

Focus accent, word length and position as cues to L1 and L2 word recognition

The present study examines native and nonnative perceptual processing of semantic information conveyed by prosodic prominence. Five groups of German learners of English each listened to one of 5 experimental conditions. Three conditions differed in place of focus accent in the sentence and two conditions were with spliced stimuli. The experiment condition was presented first in the learners’ L1 (German) and then in a similar set in the L2 (English). The effect of the accent condition and of the length and position of the target in the sentence was evaluated in a probe recognition task. In both the L1 and L2 tasks there was no significant effect in any of the five focus conditions. Target position and target word length had an effect in the L1 task. Word length did not affect accuracy rates in the L2 task. For probe recognition in the L2, word length and the position of the target interacted with the focus condition

Determining the extent to which L1 learner choices influence the L2 : exploring semantic and syntactic choices

This study tests Jiang’s (2004) 3-stage model of second language (L2) vocabulary acquisition. Jiang observed continued first language (L1) [Korean] semantic mediation in L2 processing among advanced L2 speakers. We hypothesise, however, that mediation might depend on the developing proficiency of the L2 learner and the relationship between L1 and L2. We explored the extent to which L1 background influences the processing of semantics and syntax in L2 (English). Three different L1 subject groups (n=30 per group): English, European, and Japanese. L1 European speakers were tested because their L1 shares the same word order as the L2, in contrast to L1 Japanese speakers. Two reaction time (RT) experiments were conducted to determine whether strings of words accurately reflect English syntax or semantics. Using the L1 English subject group as a control, we compared the choices made by our three groups. We also examined the L2 (English) learners’ vocabulary size. Overall the RTs were slower for incorrect syntactic word strings. The syntax RTs of the European and Japanese groups showed differences between correct and incorrect strings. However, the Japanese group showed no difference between SVO correct and incorrect strings. The semantic RTs did not differ between the L2 groups but the control group was faster. Initial findings suggest that L2 word order judgement latencies are mediated more by L1 word order; however, L2 semantic judgement latencies seem less mediated by differences in L1 word order. The findings are discussed in light of Jiang’s model and how the role of L1 word order is closer related to L2 syntactic processing than semantic processing. References Jiang, N. (2004) ‘Semantic transfer and its implications for vocabulary teaching in a second language’. The Modern Language Journal, 88 (3), pp.416-432