Linguistics Theses and Dissertations
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Item Future reference 'without' future morphology(2024) Mendes, Jéssica Viana; Hacquard, Valentine; Santorio, Paolo; Linguistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)In some languages, present morphology can be used to refer to non-scheduled future events. Since this form of future reference is constrained to certain subordinate environments, like conditional antecedents (‘If John gets a new job, he played his cards right’) and relative clauses (‘Everyone who gets invited to this party is very lucky’), I propose to call the phenomenon Subordinate Future (SF). Two factors have hindered our understanding of the SF: First, the SF often occurs in modalized sentences, which makes it difficult to tease apart its contribution from that of the environment. Second, present morphology in English can express several readings; therefore, the appearance of this future is not particularly informative. This dissertation brings new intra- and cross-linguistic evidence to bear on the nature and the meaning of the SF. I observe that, in addition to temporal displacement, the SF also introduces modal displacement. Then, I argue that the source of this modality is a subjunctive mood morpheme, which is silent in English, but pronounced in Portuguese. I proceed to decompose the semantics of the subjunctive. I propose that the subjunctive should be treated as a Heimian indefinite (Heim, 1982) ranging over situations. Simply put, the role of the subjunctive is to introduce a situation variable. The motivation for my proposal comes from the behavior of the subjunctive in relative clauses, and from the anaphoric pattern of sentences with the SF. In relative clauses, the SF blocks a specific reading of the DP. Besides that, the SF seems to be able to ‘bind’ the situation variable of predicates outside of its domain of c-command, giving rise to modal donkey anaphora. These two facts would be difficult to reconcile with a quantificational treatment of the subjunctive. I then turn my attention to the temporal interpretation of the phenomenon. As Crouch (1993, 1994) observed, this future is also able to anchor the temporal interpretation of clauses outside of its domain of c-command. I propose that this effect is a byproduct of modal donkey anaphora, and demonstrate how casting my proposal in terms of situations provides a natural account of the phenomenon. I conclude with a comparison between my proposal and existing accounts.Item A world without words: A non-lexicalist framework for psycho- and neuro-linguistics(2024) Krauska, Alexandra; Lau, Ellen; Linguistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)In standard models of language production or comprehension, the elements which are retrieved from memory and combined into a syntactic structure are “lemmas” or “lexical items”. Such models implicitly take a “lexicalist” approach, which assumes that lexical items store meaning, syntax, and form together, that syntactic and lexical processes are distinct, and that syntactic structure does not extend below the word level. Across the last several decades, linguistic research examining a typologically diverse set of languages has provided strong evidence against this approach. These findings suggest that syntactic processes apply both above and below the “word” level, and that both meaning and form are partially determined by the syntactic context. This has significant implications for psychological and neurological models of language processing as well as for the way that we understand different types of aphasia and other language disorders. As a consequence of the lexicalist assumptions of these models, many kinds of sentences that speakers produce and comprehend - in a variety of languages, including English - are challenging for them to account for. In order to move away from lexicalism in psycho- and neuro-linguistics, it is not enough to simply update the syntactic representations of words or phrases; the processing algorithms involved in language production are constrained by the lexicalist representations that they operate on, and thus also need to be reimagined. This dissertation discusses the issues with lexicalism in linguistic theory as well as its implications in psycho- and neuro-linguistics. In addition, I propose a non-lexicalist model of language production, the “WithOut Words” (WOW) model, which does not rely on lemma representations, but instead represents that knowledge as independent mappings between meaning and syntax, and syntax and form, with a single integrated stage for the retrieval and assembly of syntactic structure. Based on this, the model suggests that neural responses during language production should be modulated not just by the pieces of meaning, syntax, and form, but also by the complexity of the mapping processes which link those separate representations. This prediction is supported by the results of a novel experimental paradigm using electroencephalography (EEG) during language production, which observes greater neural responses for meaning-syntax and syntax-form mapping complexity in two separate time windows. Finally, I re-evaluate the dissociation between regular and irregular verbs in aphasia, which has been used as supporting evidence for a distinction between the grammar and the lexicon. By training recurrent neural networks and measuring their performance after lesioning, I show that the observed clinical data can be accounted for within a single mechanism. By moving away from lexicalist assumptions, the non-lexicalist framework described in this dissertation provides better cross-linguistic coverage and aligns better with contemporary syntactic theory.Item MODELING ADAPTABILITY MECHANISMS OF SPEECH PERCEPTION Nika Jurov(2024) Jurov, Nika; Feldman, Naomi H.; Idsardi, William; Linguistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Speech is a complex, redundant and variable signal happening in a noisy and ever changing world. How do listeners navigate these complex auditory scenes and continuously and effortlessly understand most of the speakers around them? Studies show that listeners can quickly adapt to new situations, accents and even to distorted speech. Although prior research has established that listeners rely more on some speech cues (or also called features or dimensions) than others, it is yet not understood how listeners weight them flexibly on a moment-to-moment basis when the input might deviate from the standard speech. This thesis computationally explores flexible cue re-weighting as an adaptation mechanism using real speech corpora. The computational framework it relies on is rate distortion theory. This framework models a channel that is optimized on a trade off between distortion and rate: on the one hand, the input signal should be reconstructed with minimal error after it goes through the channel. On the other hand, the channel needs to extract parsimonious information from the incoming data. This channel can be implemented as a neural network with a beta variational auto-encoder. We use this model to show that two mechanistic components are needed for adaptation: focus and switch. We firstly show that focus on a cue mimics humans better than cue weights that simply depend on long term statistics as has been largely assumed in the prior research. And second, we show a new model that can quickly adapt and switch weighting the features depending on the input of a particular moment. This model's flexibility comes from implementing a cognitive mechanism that has been called ``selective attention" with multiple encoders. Each encoder serves as a focus on a different part of the signal. We can then choose how much to rely on each focus depending on the moment. Finally, we ask whether cue weighting is informed by being able to separate the noise from speech. To this end we adapt a feature disentanglement adversarial training from vision to disentangle speech (noise) features from noise (speech) labels. We show that although this does not give us human-like cue weighting behavior, there is an effect of disentanglement of weighting spectral information slightly more than temporal information compared to the baselines. Overall, this thesis explores adaptation computationally and offers a possible mechanistic explanation for ``selective attention'' with focus and switch mechanisms, based on rate distortion theory. It also argues that cue weighting cannot be determined solely on speech carefully articulated in laboratories or in quiet. Lastly, it explores a way to inform speech models from a cognitive angle to make the models more flexible and robust, like human speech perception is.Item Topics in the Syntax and Semantics of Coordinate Structures(1993) Munn, Alan Boag; Hornstein, Norbert; Linguistics; Digital Repository at the University of Maryland; University of Maryland (College Park, MD)This thesis is concerned with developing a syntax for coordinate structures which is compatible with both the syntactic behaviour of conjunction structures and with their semantics. It argues that coordinate structures are asymmetrical, hierarchical structures that conform with X-bar theory. The conjunction head projects a phrase which is adjoined to the first conjunct. This provides an account of a number of syntactic asymmetries in conjunct ordering including agreement and binding asymmetries and provides a principled analysis of Across-the-Board extraction as instances of parasitic gaps. It further argues that the Coordinate Structure Constraint cannot be a syntactic constraint, but rather must be a condition on conjoining identical semantic categories. This provides an account of unlike category coordination which is shown to be freely possible if semantic identity is preserved and no independent syntactic constraints are violated, a result which follows from the adjunct nature of the coordinate structure. In order to account for the semantic identity, it is proposed that at Logical Form, each conjunct is a predicate in an identification relation with the conjunction head, which raises to take scope over all the conjuncts. Assuming theta role assignment at LF, only the conjunction head receives a theta role; none of the conjuncts does. Because each conjunct is in a predication relation with the conjunction head at LF, the semantic identity constraint follows directly. The fact that the conjuncts do not receive a theta role accounts for their inability to act as antecedents for reflexive binding and for fact that modal adverbs can appear inside conjoined NPs. The proposed analysis assimilates coordinate structures directly to plurals, and argues that a consequence of the proposed LF is that all natural language conjunction and disjunction is group forming rather than propositional. All semantic ambiguities between distributed and collective coordination can then be derived with the appropriate logical representation for plurals in general, rather than having a separate semantics altogether for coordination.Item GENERATING AND MEASURING PREDICTIONS IN LANGUAGE PROCESSING(2023) Nakamura, Masato; Philips, Colin; Linguistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Humans can comprehend utterances quickly, efficiently, and often robustly against noise in the inputs. Researchers have argued that such a remarkable ability is supported by prediction of upcoming inputs. If people use the context to infer what they would hear/see and prepare for likely inputs, they should be able to efficiently process the predicted inputs.This thesis investigates how contexts can predictively activate lexical representations (lexical pre-activation). I address two different aspects of prediction: (i) how pre-activation is generated using contextual information and stored knowledge, and (ii) how pre-activation is reflected in different measures. I first assess the linking hypothesis of the speeded cloze task, a measure of pre-activation, through computational simulations. I demonstrate that an earlier model accounts for qualitative patterns of human data but fails to predict quantitative patterns. I argue that a model with an additional but reasonable assumption of lateral inhibition successfully explains these patterns. Building on the first study, I demonstrate that pre-activation measures fail to align with each other in cases called argument role reversals, even if the time courses and stimuli are carefully matched. The speeded cloze task shows that “role-appropriate” serve in ... which customer the waitress had served is more strongly pre-activated compared to the “role- inappropriate” serve in ... which waitress the customer had served. On the other hand, the N400 amplitude, which is another pre-activation measure, does not show contrasts be- tween the role-appropriate and inappropriate serve. Accounting for such a mismatch between measures in argument role reversals provides insights into whether and how argument roles constrain pre-activation as well as how different measures reflect pre-activation. Subsequent studies addressed whether pre-activation is sensitive to argument roles or not. Analyses of context-wise variability of role-inappropriate candidates suggest that there are some role-inappropriate pre-activations even in the speeded cloze task. The next study at- tempts to directly contrast pre-activations of role-appropriate and inappropriate candidates, eliminating the effect of later confounding processes by distributional analyses of reaction times. While one task suggests that role-appropriate candidates are more strongly pre- activated compared to the role-inappropriate candidates, the other task suggests that they have matched pre-activation. Finally, I examine the influence of role-appropriate competitors on role-inappropriate competitors. The analyses of speeded cloze data suggest that N400 amplitudes can be sensitive to argument roles when there are strong role-appropriate competitors. This finding can be explained by general role-insensitivity and partial role-sensitivity in pre-activation processes. Combined together, these studies suggest that pre-activation processes are generally insensitive to argument roles, but some role-sensitive mechanisms can cause role-sensitivity in pre-activation measures under some circumstances.Item The Learning and Usage of Second Language Speech Sounds: A Computational and Neural Approach(2023) Thorburn, Craig Adam; Feldman, Naomi H; Linguistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Language learners need to map a continuous, multidimensional acoustic signal to discrete abstract speech categories. The complexity of this mapping poses a difficult learning problem, particularly for second language learners who struggle to acquire the speech sounds of a non-native language, and almost never reach native-like ability. A common example used to illustrate this phenomenon is the distinction between /r/ and /l/ (Goto, 1971). While these sounds are distinct in English and native English speakers easily distinguish the two sounds, native Japanese speakers find this difficult, as the sounds are not contrastive in their language. Even with much explicit training, Japanese speakers do not seem to be able to reach native-like ability (Logan, Lively, & Pisoni, 1991; Lively, Logan & Pisoni, 1993) In this dissertation, I closely explore the mechanisms and computations that underlie effective second-language speech sound learning. I study a case of particularly effective learning--- a video game paradigm where non-native speech sounds have functional significance (Lim & Holt, 2011). I discuss the relationship with a Dual Systems Model of auditory category learning and extend this model, bringing it together with the idea of perceptual space learning from infant phonetic learning. In doing this, I describe why different category types are better learned in different experimental paradigms and when different neural circuits are engaged. I propose a novel split where different learning systems are able to update different stages of the acoustic-phonetic mapping from speech to abstract categories. To do this I formalize the video game paradigm computationally and implement a deep reinforcement learning network to map between environmental input and actions. In addition, I study how these categories could be used during online processing through an MEG study where second-language learners of English listen to continuous naturalistic speech. I show that despite the challenges of speech sound learning, second language listeners are able to predict upcoming material integrating different levels of contextual information and show similar responses to native English speakers. I discuss the implications of these findings and how the could be integrated with literature on the nature of speech representation in a second language.Item ON SERIAL VERB CONSTRUCTIONS(1992) Wu, Daoping; Hornstein, Norbert; Linguistics; University of Maryland (College Park, Md); Digital Repository at the University of MarylandThe term serial verb construction (SVC) refers to a construction in which more than one verb are not connected by any lexical device such as conjunction and punctuation, etc.. This construction is quite popular in Chinese, Caribbean creoles, West African languages, and Dravidian languages. Structurally, the SVCs may be compounds, clauses or phrases. The clausal SVCs have been attested in all the serialized languages. The compound SVcs are reported in Chinese and Edo. Only a few instances of phrasal SVCs have been found in Dravidian languages. The compound SVCs in Chinese can consist of two verbs or a verb plus an adjective. The productive compound can only have the following structures: V trans. +V intrans., V trans + A and V intrans. + A. Among the three compounds, the head of the compound must link to both the external and the internal arguments when it is transitive. The nonhead adjective can link to either the external argument or the internal argument, while the nonhead verb can only link to the internal argument, and in most cases, the intransitive verb must be unaccusative. Feature Percolation Convention and the Case requirements generate all the grammatical compound SVCs and rule out all the ungrammatical ones. These rules also can well account for the differences between the VV compound and the VA compound. This conforms to what the Feature Percolation Convention and the Case requirement predict. It is suggested that the syntactic SVCs under discussion are clausal because of facts concerning their binding properties. This analysis is first proposed by Bickerton & Iatridou(1989) in their study of the Caribbean creoles. With this analysis, if the first verb in an SVC is in the matrix clause, the second verb is in an adjunct clause attached to the V' position of the matrix clause. This analysis obtains support from Chinese. In this respect, the only difference between Chinese and the Caribbean creoles is that the adjunct clause has two adjoining positions. Furthermore it is proposed in this thesis that the adjunct clause is a CP rather than an IP.Item Island Constraints: What is there for children to learn?(2022) Hirzel, Mina; Lidz, Jeffrey; Lau, Ellen; Linguistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This dissertation presents behavioral studies that target the early syntactic representations of wh-movement during infancy and early childhood. Previous studies show that by 20 months-old, infants represent wh-movement and use this knowledge to respond to wh-questions during language comprehension tasks (Gagliardi 2012; Gagliardi et al., 2016; Seidl et al., 2003). Studies probing the nature of early representations of wh-movement show that by around 4 years-old, children represent island constraints (e.g., de Villiers et al., 1990; de Villiers & Roeper, 1995a, 1995b; Fetters & Lidz, 2016; Goodluck et al., 1992). It remains unclear how knowledge of wh-movement develops. What is the source of this ‘empirical gap’ between the onset of knowledge of wh- movement, and the observation that children respect island constraints? One possibility is that knowledge of island constraints is a component of Universal Grammar (e.g., Chomsky 1965, 1986; Hornstein & Lightfoot 1981). In this case, the ‘empirical gap’ in the linguistic abilities of infants compared to young children isn’t indicative of their linguistic knowledge, but rather the difficulties with testing infants and toddlers on complex syntax. Another possibility is that knowledge of island constraints is acquired via experience (e.g., Pearl & Sprouse, 2013). In this case, the ‘empirical gap’ reflects a knowledge gap, and there’s no evidence for knowledge of island constraints during infancy because it has yet to be acquired. Experiment 1 shows that by 19 months-old, infants have knowledge of wh-movement, and use this knowledge during language comprehension. Results are consistent with recent work which shows that 18 month-olds, but not 17 month-olds, know that wh-phrases co-occur with gap positions in wh-object questions (Perkins & Lidz, 2021). Experiment 2 shows that 3 year-olds respect locality constraints on wh-movement in wh- questions, and Experiment 3 shows that adults behave as expected on this task. Experiments 4 and 5 test children and adults on locality constraints on wh- movement in relative clauses, but these results are inconclusive (likely due to difficulties with moving the task online). The results of Experiment 3 raises challenges for learning hypotheses of island constraints which emphasize the role of linguistic experience. Learning models which propose that linguistic experience is the key factor in the acquisition of island constraints must consider these behavioral results when estimating the amount of data that the learner needs to solve the acquisition problem. These behavioral results are consistent with the hypothesis that knowledge of island constraints is innate, but further work is needed to close the ‘empirical gap’ between the onset of knowledge of wh- movement and the onset of knowledge of island constraints.Item What could go wrong? Linguistic illusions and incremental interpretation(2022) Muller, Hanna; Phillips, Colin; Linguistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The systems underlying incremental sentence comprehension are, in general, highly successful - comprehenders typically understand sentences of their native language quickly and accurately. The occasional failure of the system to deliver an appropriate representation of a sentence is therefore potentially illuminating. There are many ways the comprehender's general success could in principle be accomplished; the systematic pattern of failures places some constraints on the possible algorithms. This dissertation explores two cases of systematic failure, negative polarity illusions and substitution illusions (sometimes called "Moses illusions") with the goal of identifying the specific circumstances under which the illusion arises, and, as a consequence, the specific constraints placed on possible implementations of linguistic knowledge. In the first part of this dissertation, I explore the profile of the negative polarity illusion, a case in which a sentence containing an unlicensed negative polarity item and a preceding, but not structurally-relevant licensor is perceived as if it is acceptable, at least in early stages of processing. I consider various proposals for the grammatical knowledge that determines the restricted distribution of negative polarity items, and possible algorithms for using that grammatical knowledge in real time to process a sentence containing a negative polarity item. I also discuss possible parallels between negative polarity illusions and superficially-similar illusory phenomena in other domains, such as subject-verb agreement. Across sixteen experiments, I show that the profile of the illusion is more restricted than previously thought. Illusions do not always arise when an unlicensed negative polarity item is preceded by a structurally-irrelevant licensor, and the circumstances under which they do arise are quite specific. These findings suggest that the negative polarity illusion may be meaningfully distinct from other illusory phenomena, though this conclusion does not necessarily require stipulating a separate mechanism for every illusion. I discuss the implications of these findings for possible real-time implementations of grammatical knowledge. In the second part of this dissertation, I turn to the substitution illusion, a case in which a word in a trivia fact is swapped out for another word, making the sentence a world knowledge violation, but comprehenders do not consciously detect the anomalous nature of the sentence. Here I attempt to develop specific and testable hypotheses about the source of the illusion, paying particular attention to how the same mechanism that "fails" in illusion sentences (in that it does not allow the comprehender to detect the anomaly) serves the comprehender well in other circumstances. I demonstrate that the substitution illusion, like the negative polarity illusion, is more restricted than previously thought - some stimuli yield very high illusion rates while others yield very low illusion rates, and this variability appears to be non-random. In seven experiments, I pursue both a correlational approach and an experimental manipulation of illusion rates, in order to narrow the space of possible explanations for the illusion. These investigations collectively demonstrate that occasional errors in comprehension do not necessarily reflect the use of "shortcuts" in sentence processing, and can be explained by the interaction of the linguistic system with non-linguistic components of the cognitive architecture, such as memory and attention. While neither illusion phenomenon is ultimately fully explained, the research presented here constitutes an important step forward in our understanding of both domains and their broader implications.Item Are you asking me or telling me? Learning clause types and speech acts in English and Mandarin(2022) Yang, Yu'an; Hacquard, Valentine; Lidz, Jeffrey; Linguistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Languages tend to have three major clause types (declaratives, interrogatives, imperatives), dedicated to three main speech acts (assertions, questions, commands). However, the particular forms that these clause types take differ from language to language, and have to be learned. Previous experimental results suggest that by 18 months old, children differentiate these clause types and associate them with their canonical speech act. This dissertation investigates how children learn to identify different clause types and speech acts. To learn clause types, children need to identify the right categories of clauses (the "clustering problem") and figure out what speech act they are canonically used for (the "labeling problem"). I investigate the extent to which learners need to rely on pragmatic information (i.e., knowing what speech act a given utterance of a sentence is conveying), to solve not just labeling, but the clustering itself. I examine the role of pragmatics computationally by building two Bayesian clustering models. I find that morpho-syntactic and prosodic information are not enough for identifying the right clause type clustering, and that pragmatics is necessary. I applied the same model to a morphological impoverished language, Mandarin, and found that the model without pragmatics performs even worse. Speech act information is crucial for finding the right categories for both languages. Additionally, I find that a little pragmatics goes a long way. I simulate the learning process with noisy speech act information, and find that even when speech act information is noisy, the model hones in on the right clause type categories, when the model without fails. But if speech act information is useful for clause type learning, how do children figure out speech act information? I explore what kind of non-clause type cues for speech act information are present in the input. Even if children must rely on clause type information to figure out speech acts, they could have access to additional information that is unrelated to clause typing, but informative for recognizing speech act type. When speakers perform speech acts, because of the conventional functions of these speech acts on the discourse, the performance might be associated with certain socio-pragmatic features. For example, because of questions' response-elicitation function, we might expect speakers to pause longer after questions. If children are equipped with some expectations about the functions of communication, and about what questions do, they might be able to use these socio-pragmatic cues to figure out speech act. I explore two cues that could potentially differentiate questions from other speech acts: pauses, and direct eye gaze. I find that parents tend to pause longer after questions, and attend to the child more when asking questions. Therefore it is in principle plausible that there are some socio-pragmatic features that children can use, in addition to their growing knowledge of clause types to infer the speech act category of an utterance. This little bit of information about speech act could then be used to provide the information that the child needs in order to get the clause type clusters identified accurately.