Publications

Abstract

Artificial lexicons have previously been used to examine the time course of the learning and recognition of spoken words, the role of segment type in word learning, and the integration of context during spoken word recognition. However, in all of these studies the experimenter determined the frequency and order of the words to be learned. In three experiments, we asked whether adult learners choose to listen to novel words in a particular order based on their acoustic similarity. We use a new paradigm for learning an artificial lexicon in which the learner, rather than the experimenter, determines the order and frequency of exposure to items. We analyze both the proportions of selections and the temporal clustering of subjects' sampling of lexical neighborhoods during training as well as their performance during repeated testing phases (accuracy and reaction time) to determine the time course of learning these neighborhoods. In the first experiment, subjects sampled the high and low density neighborhoods randomly in early learning, and then over-sampled the high density neighborhood until test performance on both neighborhoods reached asymptote. A second experiment involved items similar to the first, but also neighborhoods that are not fully revealed at the start of the experiment. Subjects adjusted their training patterns to focus their selections on neighborhoods of increasing density was revealed; evidence of learning in the test phase was slower to emerge than in the first experiment, impaired by the presence of additional sets of items of varying density. Crucially, in both the first and second experiments there was no effect of dense vs. sparse neighborhood in the accuracy results, which is accounted for by subjects’ over-sampling of items from the dense neighborhood. The third experiment was identical in design to the second except for a second day of further training and testing on the same items. Testing at the beginning of the second day showed impaired, not improved, accuracy, except for the consistently dense items. Further training, however, improved accuracy for some items to above Day 1 levels. Overall, these results provide a new window on the time-course of learning an artificial lexicon and the role that learners’ implicit preferences, stemming from their self-selected experience with the entire lexicon, play in learning highly confusable words.

Abstract

Research on second language acquisition typically focuses on how a first language (L1) influences a second language (L2) in different linguistic domains and across modalities. This dissertation, in contrast, explores interactions between languages in the mind of a language learner by asking 1) can an emerging L2 influence an established L1? 2) if so, how is such influence realized? 3) are there parallel influences of the L1 on the L2? These questions were investigated for the expression of Manner (e.g. climb, roll) and Path (e.g. up, down) of motion, areas where substantial crosslinguistic differences exist in speech and co-speech gesture. Japanese and English are typologically distinct in this domain; therefore, narrative descriptions of four motion events were elicited from monolingual Japanese speakers (n=16), monolingual English speakers (n=13), and native Japanese speakers with intermediate knowledge of English (narratives elicited in both their L1 and L2, n=28). Ways in which Path and Manner were expressed at the lexical, syntactic, and gestural levels were analyzed in monolingual and non-monolingual production. Results suggest mutual crosslinguistic influences. In their L1, native Japanese speakers with knowledge of English displayed both Japanese- and English-like use of morphosyntactic elements to express Path and Manner (i.e. a combination of verbs and other constructions). Consequently, non-monolingual L1 discourse contained significantly more Path expressions per clause, with significantly greater mention of Goal of motion than monolingual Japanese and English discourse. Furthermore, the gestures of non-monolingual speakers diverged from their monolingual counterparts with differences in depiction of Manner and gesture perspective (character versus observer). Importantly, non-monolingual production in the L1 was not ungrammatical, but simply reflected altered preferences. As for L2 production, many effects of L1 influence were seen, crucially in areas parallel to those described above. Overall, production by native Japanese speakers who knew English differed from that of monolingual Japanese and English speakers. But L1 and L2 production within non-monolingual individuals was similar. These findings imply a convergence of L1-L2 linguistic systems within the mind of a language learner. Theoretical and methodological implications for SLA research and language assessment with respect to the 'native speaker standard language' are discussed.

Abstract

This dissertation is an ethnographic study of race and other forms of social categorization as approached through the discourse of the indigenous Chachi people of northwestern lowland Ecuador and their Afro-descendant neighbors. It combines the ethnographic methods of social anthropology with the methods of descriptive linguistics, letting social questions about racial formation guide linguistic inquiry. It provides new information about the largely unstudied indigenous South American language Cha’palaa, and connects that information about linguistic form to problems of the study of race and ethnicity in Latin America. Individual descriptive chapters address how the Cha’palaa number system is based on collectivity rather than plurality according to an animacy hierarchy that codes only human and human-like social collectivities, how a nominal set of ethnonyms linked to Chachi oral history become the recipients of collective marking as human collectivities, how those collectivities are co-referentially linked to speech participants through the deployment of the pronominal system, and how the multi-modal resource of gesture adds to these rich resources supplied by the spoken language for the expression of social realities like race. The final chapters address Chachi and Afrodescendant discourses in dialogue with each other and examine naturally occurring speech data to show how the linguistic forms described in previous chapters are used in social interaction. The central argument advances a position that takes the socially constructed status of race seriously and considers that for such constructions to exist as more abstract macro-categories they must be constituted by instances of social interaction, where elements of the social order are observable at the micro-level. In this way localized articulations of social categories become vehicles for the broader circulation of discourses structured by a history of racialized social inequality, revealing the extreme depth of racialization in human social conditioning. This dissertation represents a contribution to the field of linguistic anthropology as well as to descriptive linguistics of South American languages and to critical approaches to race and ethnicity in Latin America.

Abstract

This doctoral dissertation investigated the learning of auditory categories by applying insights from child language learning, visual category learning and phonetic categorization by adults. The experiments in chapter 2 concern supervised learning of multidimensional non-speech categories varying in two dimensions: duration and a non speech analogue of formant frequency. In experiment 1, one dimension of variation determined category membership, variation in the other dimension was irrelevant. Listeners quickly learned to categorize according to this distinction. In experiment 2, both dimensions needed to be combined to categorize correctly. Performance was much lower, but most listeners succeeded in this task. However, in a maintenance phase without feedback or distributional information, listeners reverted to a unidimensional solution. In a maintenance phase with distributional information, listeners did use both dimensions correctly, arguing for the importance of distributional information in (auditory) category acquisition. In chapter 3, the listeners had to classify the same categories, but without feedback. In experiment 1, listeners succeeded to discover the relevant dimension of variation (and ignore the irrelevant one) without feedback. Much of this learning was lost in the maintenance phase, especially for the dimension formant frequency. With two relevant dimensions (Experiment 2), listeners were not able to learn to use both dimensions and reverted to a unidimensional solution. Chapter 4 applied the paradigms of chapter 2 and 3 to the learning of speech categories. Spanish native listeners learned Dutch vowel contrast with one relevant dimension of variation. With feedback, learning was swift, although was not well maintained without feedback or distributional information. Without feedback, Spanish listeners reverted to the dimensions best known in their native phonology, formant frequency, even when distributional information pointed to duration. The results are discussed in chapter 5. The implications for models of speech acquisition are discussed.

Abstract

This thesis elaborates on a methodological approach to reliably infer cognitive preferences in an extinct evolutionary ancestor of modern humans. In attempts to understand cognitive evolution, humans have been compared to capuchin monkeys, tamarins, and chimpanzees to name but a few. But comparisons between humans and one other, maybe even distantly related primate, as interesting as they might be, will not tell us anything about an evolutionary ancestor to humans. To put it bluntly: None of the living primates, not even chimpanzees, are a human ancestor. With that in mind, we can still use a comparative approach to gain information about our evolutionary ancestors, as long as we are careful about whom we compare with whom. If a certain trait exists in all genera of a phylogenetic clade, it was most likely present in their common ancestor. The great apes are such a clade (Pongo, Gorilla, Pan and Homo). It follows that, if members of all great ape genera shared a particular cognitive preference or ability, it is most likely part of the evolutionary inheritance of the clade at least ever since their last common ancestor, and therefore also an evolutionarily old, inherited cognitive default in humans. This thesis contains studies comparing all 4 extant Hominid genera, including humans of 4 different age-groups and 2 different cultures. Results show that all great apes do indeed share some cognitive preferences, which they most likely inherited from an evolutionary ancestor. Additionally, human cognitive preferences can change away from such an inherited predisposition given ontogenetic factors, and are at least in part variably adaptable to cultural circumstance.

Abstract

Word segmentation, or detecting word boundaries in continuous speech, is not an easy task. Spoken language does not contain silences to indicate word boundaries and words partly overlap due to coarticalution. Still, adults listening to their native language perceive speech as individual words. They are able to combine different distributional cues in the language, such as the statistical distribution of sounds and metrical cues, with lexical information, to efficiently detect word boundaries. Infants in the first year of life do not command these cues. However, already between seven and ten months of age, before they know word meaning, infants learn to segment words from speech. This important step in language acquisition is the topic of this dissertation. In chapter 2, the first Event Related Brain Potential (ERP) study on word segmentation in Dutch ten-month-olds is discussed. The results show that ten-month-olds can already segment words with a strong-weak stress pattern from speech and they need roughly the first half of a word to do so. Chapter 3 deals with segmentation of words beginning with a weak syllable, as a considerable number of words in Dutch do not follow the predominant strong-weak stress pattern. The results show that ten-month-olds still largely rely on the strong syllable in the language, and do not show an ERP response to the initial weak syllable. In chapter 4, seven-month-old infants' segmentation of strong-weak words was studied. An ERP response was found to strong-weak words presented in sentences. However, a behavioral response was not found in an additional Headturn Preference Procedure study. There results suggest that the ERP response is a precursor to the behavioral response that infants show at a later age.

Abstract

This dissertation investigates the expression of spatial relationships in German Sign Language (Deutsche Gebärdensprache, DGS). The analysis focuses on linguistic expression in the spatial domain in two types of discourse: static scene description (location) and event narratives (location and motion). Its primary theoretical objectives are to characterize the structure of locative descriptions in DGS; to explain the use of frames of reference and perspective in the expression of location and motion; to clarify the interrelationship between the systems of frames of reference, signing perspective, and classifier predicates; and to characterize the interplay between iconicity principles, on the one hand, and grammatical and discourse constraints, on the other hand, in the use of these spatial devices. In more general terms, the dissertation provides a usage-based account of iconic mapping in the visual-spatial modality. The use of space in sign language expression is widely assumed to be guided by iconic principles, which are furthermore assumed to hold in the same way across sign languages. Thus, there has been little expectation of variation between sign languages in the spatial domain in the use of spatial devices. Consequently, perhaps, there has been little systematic investigation of linguistic expression in the spatial domain in individual sign languages, and less investigation of spatial language in extended signed discourse. This dissertation provides an investigation of spatial expressions in DGS by investigating the impact of different constraints on iconicity in sign language structure. The analyses have important implications for our understanding of the role of iconicity in the visual-spatial modality, the possible language-specific variation within the spatial domain in the visual-spatial modality, the structure of spatial language in both natural language modalities, and the relationship between spatial language and cognition

Abstract

This dissertation investigates the roles of several probabilistic variables in the production and comprehension of reduced Dutch affixes. The central hypothesis is that linguistic units with a high probability of occurrence are
more likely to be reduced (Jurafsky et al., 2001; Aylett & Turk, 2004). This hypothesis is tested by analyzing the acoustic realizations of affixes, which are meaning-carrying elements embedded in larger lexical units. Most of the results prove to be compatible with the main hypothesis, but some appear to run counter to its predictions. The final chapter of the thesis discusses the implications of these findings for models of speech production, models of speech perception, and probability-based accounts of reduction.

Abstract

People across the world make requests every day. We constantly rely on others to get by in the small and big practicalities of everyday life, be it getting the salt, moving a sofa, or cooking a meal. It has long been noticed that when we ask others for help we use a wide range of forms drawing on various resources afforded by our language and body. To get another to pass the salt, for example, we may say ‘Pass the salt’, or ask ‘Can you pass me the salt?’, or simply point to the salt. What do different forms of requesting give us? The short answer is that they allow us to manage different social relations. But what kind of relations? While prior research has mostly emphasised the role of long-term asymmetries like people’s social distance and relative power, this thesis puts at centre stage social relations and dimensions emerging in the moment-by-moment flow of everyday interaction. These include how easy or hard the action requested is to anticipate for the requestee, whether the action requested contributes to a joint project or serves an individual one, whether the requestee may be unwilling to do it, and how obvious or equivocal it is that a certain person or another should be involved in the action. The study focuses on requests made in everyday informal interactions among speakers of Italian. It involves over 500 instances of requests sampled from a diverse corpus of video recordings, and draws on methods from conversation analysis, linguistics and multimodal analysis. A qualitative analysis of the data is supported by quantitative measures of the distribution of linguistic and interactional features, and by the use of inferential statistics to test the generalizability of some of the patterns observed. The thesis aims to contribute to our understanding of both language and social interaction by showing that forms of requesting constitute a system, organised by a set of recurrent social-interactional concerns.