This thesis is an investigation of phenomena at the interface between syntax, semantics, and pragmatics, with the aim of arguing for a view of semantic interpretation as lexically driven yet contextually dependent. I examine regular, generative processes which operate over the lexicon to induce verbal sense shifts, and discuss the interaction of these processes with the linguistic or discourse context. I concentrate on phenomena where only an interaction between all three linguistic knowledge sources can explain the constraints on verb use: conventionalised lexical semantic knowledge constrains productive syntactic processes, while pragmatic reasoning is both constrained by and constrains the potential interpretations given to certain verbs. The phenomena which are closely examined are the behaviour of PP sentential modifiers (specifically dative and directional PPs) with respect to the lexical semantic representation of the verb phrases they modify, resultative constructions, and logical metonymy. The analysis is couched in terms of a lexical semantic representation drawing on Davis (1995), Jackendoff (1983, 1990), and Pustejovsky (1991, 1995) which aims to capture “linguistically relevant” components of meaning. The representation is shown to have utility for modeling of the interaction between the syntactic form of an utterance and its meaning. I introduce a formalisation of the representation within the framework of Head Driven Phrase Structure Grammar (Pollard and Sag 1994), and rely on the model of discourse coherence proposed by Lascarides and Asher (1992), Discourse in Commonsense Entailment. I furthermore discuss the implications of the contextual dependency of semantic interpretation for lexicon design and computational processing in Natural Language Understanding systems.

The overall purpose of this study is to investigate lexical semantic representation in bilinguals who speak typologically different languages, specifically, Mandarin and English. Three questions are posed about semantic representation: 1) Do bilingual speakers demonstrate greater heterogeneity in semantic knowledge than monolingual speakers; 2) To what extent do bilingual speakers use paradigmatic and syntagmatic relations to organize their semantic knowledge; and 3) What is the cross- linguistic overlap in bilingual speakers' semantic representation. Thirty Mandarin- English bilingual adults and 30 monolingual English-speaking adults participated in a repeated word association task and generated three associations to each of 36 stimuli. The bilingual speakers completed the same task in their two languages on two different days whereas the monolingual speakers responded to the same 36 stimuli on two different days. Results indicated that 1) the bilingual speakers produced a more heterogeneous set of responses in English than monolingual speakers; heterogeneity was greater in English than Mandarin among the bilingual speakers; 2) the bilingual speakers produced more paradigmatic associations (e.g., happy-sad, spoon-chopsticks, catch-throw) and fewer syntagmatic associations (e.g., happy-smile, spoon-eat, catch-ball) than the monolingual speakers; and 3) approximately 48% of the bilingual speakers' responses were cross- linguistic synonyms, whereas approximately 76% of the monolingual speakers' responses were identical from session 1 to session 2. These findings suggest that late bilinguals (second language learners) use categorical relations to organize their semantic knowledge to a greater extent than monolingual speakers and that reduced experience with a second language can lead to greater heterogeneity in semantic knowledge in that language. The findings also suggest that bilingual speakers have more distributed semantic representations than monolingual speakers. Additional research is needed to explore the areas of heterogeneity, categorical organization, and cross-linguistic overlap in order to further our understanding of bilingual speakers' semantic knowledge representation. / text

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The dramatic effects of brain damage can provide some of the most interesting insights into the nature of normal cognitive performance. In recent years a number of neuropsychological studies have reported a particular form of cognitive impairment where patients have problems recognising objects from one category but remain able to recognise those from others. The most frequent ‘category-specific’ pattern is an impairment identifying living things, compared to nonliving things. The reverse pattern of dissociation, i.e., an impairment recognising and naming nonliving things relative to living things, has been reported albeit much less frequently. The objective of the work carried out in this thesis was to investigate the organising principles and anatomical correlates of stored knowledge for categories of living and nonliving things. Three complementary cognitive neuropsychological research techniques were employed to assess how, and where, this knowledge is represented in the brain: (i) studies of normal (neurologically intact) subjects, (ii) case-studies of neurologically impaired patients with selective deficits in object recognition, and (iii) studies of the anatomical correlates of stored knowledge for living and nonliving things on the brain using magnetoencephalography (MEG). The main empirical findings showed that semantic knowledge about living and nonliving things is principally encoded in terms of sensory and functional features, respectively. In two case-study chapters evidence was found supporting the view that category-specific impairments can arise from damage to a pre-semantic system, rather than the assumption often made that the system involved must be semantic. In the MEG study, rather than finding evidence for the involvement of specific brain areas for different object categories, it appeared that, when subjects named and categorised living and nonliving things, a non-differentiated neural system was involved.

Inductive reasoning (IR) requires efficient working memory (WM). Research shows that the prefrontal cortex (PFC) is involved during WM tasks and that PFC functioning declines with age. The ability to comprehend and update text-based information requires an intact PFC and efficient WM and IR. The current study presented a series of messages about the investigation of a warehouse fire to 48 young and 48 older adults. One message contained a piece of misinformation which another message corrected later. It was hypothesized that a memory cue to the misinformation with the correction statement should benefit older adults the most during the updating process. A text-based level and situation model level measured updating. The text-based level is only information from the text but is not necessarily verbatim. The situation model level is the overall meaning of the text, including inferences and assumptions. Results show that unlike young adults, older adults are not capable of recalling the text at the text-based level. However, older adults are capable of performing like young adults at the situation model level. This suggests that older adults are capable of updating causal information in text material as long as a memory cue to the misinformation is provided within the correction statement.

We used functional magnetic resonance imaging to investigate how the human brain processes information about social groups in three domains. Study 1: Semantic knowledge. Participants were scanned while they answered questions about their knowledge of both social categories and non-social categories like object groups and species of nonhuman animals. Brain regions previously identified in processing semantic information are more robustly engaged by nonsocial semantics than stereotypes. In contrast, stereotypes elicit greater activity in brain regions implicated in social cognition. These results suggest that stereotypes should be considered distinct from other forms of semantic knowledge. Study 2: Theory of mind. Participants were scanned while they answered questions about the mental states and physical attributes of individual people and groups. Regions previously associated with mentalizing about individuals were also robustly responsive to judgments of groups. However, multivariate searchlight analysis revealed that several of these regions showed distinct multivoxel patterns of response to groups and individual people. These findings suggest that perceivers mentalize about groups in a manner qualitatively similar to mentalizing about individual people, but that the brain nevertheless maintains important distinctions between the representations of such entities. Study 3: Social categorization. Participants were scanned while they categorized the sex and race of unfamiliar Black men, Black women, White men, and White women. Multivariate pattern analysis revealed that multivoxel patterns in FFA--but not other face-selective brain regions, other category-selective brain regions, or early visual cortex--differentiated faces by sex and race. Specifically, patterns of voxel-based responses were more similar between individuals of the same sex than between men and women, and between individuals of the same race than between Black and White individuals. These results suggest that FFA represents the sex and race of faces. Together, these three studies contribute to a growing cognitive neuroscience of social groups. / Psychology

This present study investigated generative naming in Korean-English bilingual adult speakers. Specific aims were: 1) to compare the total number of named items generated in Korean-English bilingual adults in the categories of Food, Clothes, and Animals, 2) to investigate the relationship between language proficiency and the total number of items named in each category and across categories for each language, and 3) to examine the relationship between language proficiency and the total number of overlapped items (doublets) in each category and across categories. Twenty five Korean-English bilingual adults named as many different items as they could in 60 seconds in the categories of Food, Clothes, and Animals in Korean and English. Results indicated that the participants produced significantly more items in Korean than English in all categories. Participants named fewer items in the category of Clothes than in the categories of Food and Animals, suggesting that generating items for the Clothes category was more difficult than for the other categories. No significant correlations were found between participants’ language proficiency and the total number of items generated and the number of doublets. There is a need to develop more reliable measures of language proficiency for bilingual speakers. / text

Autonomous mobile robots are being developed with the aim of accomplishing complex tasks in different environments, including human habitats as well as less friendly places, such as distant planets and underwater regions. A major challenge faced by such robots is to make sure that their actions are executed correctly and reliably, despite the dynamics and the uncertainty inherent in their working space. This thesis is concerned with the ability of a mobile robot to reliably monitor the execution of its plans and detect failures. Existing approaches for monitoring the execution of plans rely mainly on checking the explicit effects of plan actions, i.e., effects encoded in the action model. This supposedly means that the effects to monitor are directly observable, but that is not always the case in a real-world environment. In this thesis, we propose to use semantic domain-knowledge to derive and monitor implicit expectations about the effects of actions. For instance, a robot entering a room asserted to be an office should expect to see at least a desk, a chair, and possibly a PC. These expectations are derived from knowledge about the type of the room the robot is entering. If the robot enters a kitchen instead, then it should expect to see an oven, a sink, etc. The major contributions of this thesis are as follows. • We define the notion of Semantic Knowledge-based Execution Monitoring SKEMon, and we propose a general algorithm for it based on the use of description logics for representing knowledge. • We develop a probabilistic approach of semantic Knowledge-based execution monitoring to take into account uncertainty in both acting and sensing. Specifically, we allow for sensing to be unreliable and for action models to have more than one possible outcome. We also take into consideration uncertainty about the state of the world. This development is essential to the applicability of our technique, since uncertainty is a pervasive feature in robotics. • We present a general schema to deal with situations where perceptual information relevant to SKEMon is missing. The schema includes steps for modeling and generating a course of action to actively collect such information. We describe approaches based on planning and greedy action selection to generate the information-gathering solutions. The thesis also shows how such a schema can be applied to respond to failures occurring before or while an action is executed. The failures we address are ambiguous situations that arise when the robot attempts to anchor symbolic descriptions (relevant to a plan action) in perceptual information. The work reported in this thesis has been tested and verified using a mobile robot navigating in an indoor environment. In addition, simulation experiments were conducted to evaluate the performance of SKEMon using known metrics. The results show that using semantic knowledge can lead to high performance in monitoring the execution of robot plans.

This study was an investigation into the aural and written receptive knowledge of the English semantics of English lexis that is loanwords in the Japanese language and the predictive strength of the variables of semantic distance, concreteness/abstractness, polysemy, phonological distance, number of syllables, number of phonemes, number of letters, part of speech (POS), English Frequency, and frequency in Japanese in relation to accurate semantic knowledge. The participants (N = 215) were first- and second-year, non-English majors at a large university in Western Japan. The participants were from 10 intact English classes focused on reading, writing, and communication skills. Data were collected using eight instruments: the Listening Vocabulary Levels Test, Aural Loanword Test, Aural Non-Loanword Test, New Vocabulary Levels Test, Written Loanword Test, Written Non-Loanword Test, and Japanese Loanword Frequency Rating Task. Additionally, data were collected from five Japanese L1 speakers highly proficient at English on the Semantic Distance Rating Task. The data were first analyzed using the Rasch dichotomous model to examine instrument reliability and validity as well as to transform the data into Rasch person ability estimates and Rasch item ability estimates. Pearson correlations were used to determine the strength of the relationship between loanwords and non-loanwords. Repeated-measures ANOVA—with follow up t-tests were used to determine the differences between the four semantic tests: the Aural Loanword Test, the Aural Non-Loanword Test, the Written Loanword Test, and the Written Non-Loanword Test. Four multiple linear regression analyses were conducted using the predictor variables semantic distance, concreteness/abstractness, phonological distance, number of syllables, number of phonemes, number of letters, part of speech, English Frequency, and frequency in Japanese. The results of the Pearson analyses showed strong correlations between the aural and written loanword and non-loanword measures. This finding indicated that the participants’ knowledge of loanwords was relatively equivalent to their knowledge of non-loanwords. The results of the comparison between aural and written loanword knowledge showed that written knowledge of loanwords was greater than aural knowledge of loanwords. Further comparisons between the loanword and non-loanword tests showed that receptive aural non-loanword knowledge was greater than aural loanword knowledge, and that written non-loanword knowledge was greater than written loanword knowledge. These comparisons showed that English semantic knowledge of loanwords was less accurate than that of non-loanwords, which implied that the accurate acquisition of English semantic knowledge of loanwords was impeded by Japanese L1 lexical knowledge. The results of the multiple regressions indicated that the only substantial predictor of lexical acquisition for both loanwords and non-loanwords in both modalities (aural and written) was English Frequency. Although the effect size of English frequency was substantial, it was less so on the aural and written loanword measures. This finding implied that English linguistic gains of repeated exposure were most likely muted by entrenched L1 semantic knowledge. Overall, the results showed that loanwords are generally acquired with greater difficulty than non-loanwords and that they should not always be considered a form of receptive knowledge of English lexis. / Applied Linguistics

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