Research

Although there is broad agreement that many ERP components reflect error signals generated during an unexpected linguistic event, there are least two distinct aspects of the process that the ERP signals may reflect. The first is the content of an error, which is the local discrepancy between an observed form and any expectations about upcoming forms, without any reference to why those expectations were held. The second aspect is the cause of an error, which is a context-aware analysis of why the error arose. The current study examines the processes involved in prediction of past tense marking on verbal morphology in Hindi. This is a case where an error with the same local characteristics can arise from very different cues, one syntactic in origin (ergative case marking), and the other semantic in origin (a past tense adverbial). Results suggest that the parser does indeed track the cause in addition to the content of errors. Despite the fact that the critical manipulation of verb tense marking was identical across cue types, the nature of the cue led to distinct patterns of ERPs in response to anomalous verbal morphology. When verb tense was predicted based upon semantic cues, an incorrect future tense form elicited an early negativity in the 200-400 ms interval with a posterior distribution. In contrast, when verb tense was predicted based upon morphosyntactic cues, an incorrect future tense form elicited a right-lateralized anterior negativity (RAN) during the 300-500 ms interval, as well as a P600 response with a broad distribution.

Many syntactic phenomena have received competing accounts, either in terms of formal grammatical mechanisms, or in terms of independently motivated properties of language processing mechanisms (“reductionist” accounts). A variety of different types of argument have been put forward in efforts to distinguish these competing accounts. This article critically examines a number of arguments that have been offered as evidence in favour of formal or reductionist analyses, and concludes that some types of argument are more decisive than others. It argues that evidence from graded acceptability effects and from isomorphism between acceptability judgements and on-line comprehension profiles are less decisive. In contrast, clearer conclusions can be drawn from cases of overgeneration, where there is a discrepancy between acceptability judgements and the representations that are briefly constructed on-line, and from tests involving individual differences in cognitive capacity. Based on these arguments, the article concludes that a formal grammatical account is better supported in some domains, and that a reductionist account fares better in other domains. Phenomena discussed include island constraints, agreement attraction, constraints on anaphora, and comparatives.

Our understanding of human learning is increasingly informed by findings from multiple fields—psychology, neuroscience, computer science, linguistics, and education. A convergence of insights is forging a “new science of learning” within cognitive science, which promises to play a key role in developing intelligent machines (1, 2). A long-standing fundamental issue in theories of human learning is whether there are specialized learning mechanisms for certain tasks or spheres of activity (domains). For example, is learning how to open a door (turning the handle before pulling) the same kind of “learning” as putting up and taking down scaffolding (where disassembly must be done in the reverse order of assembly)? Surprisingly, this issue plays out within the domain of human language.

That we perceive our environment as a unified scene rather than individual streams ofauditory, visual, and other sensory information has recently provided motivation tomove past the long-held tradition of studying these systems separately. Although they are each unique in their transduction organs, neural pathways, and cortical primaryareas, the senses are ultimately merged in a meaningful way which allows us to navigate the multisensory world. Investigating how the senses are merged has becomean increasingly wide field of research in recent decades, with the introduction andincreased availability of neuroimaging techniques. Areas of study range from multisensory object perception to cross-modal attention, multisensory interactions,and integration. This thesis focuses on audio-visual speech perception, with special focus on facilitatory effects of visual information on auditory processing. When visual information is concordant with auditory information, it provides an advantagethat is measurable in behavioral response times and evoked auditory fields (Chapter3) and in increased entrainment to multisensory periodic stimuli reflected by steady-state responses (Chapter 4). When the audio-visual information is incongruent, thecombination can often, but not always, combine to form a third, non-physicallypresent percept (known as the McGurk effect). This effect is investigated (Chapter 5) using real word stimuli. McGurk percepts were not robustly elicited for a majority of stimulus types, but patterns of responses suggest that the physical and lexicalproperties of the auditory and visual stimulus may affect the likelihood of obtainingthe illusion. Together, these experiments add to the growing body of knowledge that suggests that audio-visual interactions occur at multiple stages of processing.

This dissertation explores the hypothesis that language processing proceeds in “windows” that correspond to representational units, where sensory signals are integrated according to time-scales that correspond to the rate of the input. To investigate universal mechanisms, a comparison of signed and spoken languages is necessary. Underlying the seemingly effortless process of language comprehension is the perceiver’s knowledge about the rate at which linguistic form and meaning unfold in time and the ability to adapt to variations in the input. The vast body of work in this area has focused on speech perception, where the goal is to determine how linguistic information is recovered from acoustic signals. Testing some of these theories in the visual processing of American Sign Language (ASL) provides a unique opportunity to better understand how sign languages are processed and which aspects of speech perception models are in fact about language perception across modalities. The first part of the dissertation presents three psychophysical experiments investigating temporal integration windows in sign language perception by testing the intelligibility of locally time-reversed sentences. The findings demonstrate the contribution of modality for the time-scales of these windows, where signing is successively integrated over longer durations (~ 250-300 ms) than in speech (~ 50-60 ms), while also pointing to modality-independent mechanisms, where integration occurs in durations that correspond to the size of linguistic units. The second part of the dissertation focuses on production rates in sentences taken from natural conversations of English, Korean, and ASL. Data from word, sign, morpheme, and syllable rates suggest that while the rate of words and signs can vary from language to language, the relationship between the rate of syllables and morphemes is relatively consistent among these typologically diverse languages. The results from rates in ASL also complement the findings in perception experiments by confirming that time-scales at which phonological units fluctuate in production match the temporal integration windows in perception. These results are consistent with the hypothesis that there are modalityindependent time pressures for language processing, and discussions provide a synthesis of converging findings from other domains of research and propose ideas for future investigations.

The purpose of this dissertation is to explore the nature of intervention effects seen in various constructions like Wh-scope marking, raising and passivization. In particular, this dissertation argues in favor of a movement account for all these cases and supports the idea that (syntactic) movement is inevitable and sufficient enough to provide a unified account of various structural relations (Hornstein, 2009). It further argues that movement always happens in narrow syntax, even when it isn’t visible. For some of these invisible cases, this dissertation suggests head movement as an alternative to LF movement and Agree. The second aim of this dissertation is to explain intervention effects in terms of relativized minimality (Rizzi 1990, 2004). In this consideration, this dissertation sides with Boeckx & Lasnik (2006) view that not all minimality violations are derivational: some are repairable, indicating that they must be treated as representational constraints, while others are not, indicating that they are derivational. In this study, the dissertation not only reviews cross-linguistic facts from languages like English, German, Chinese, Japanese, and Icelandic but also provides novel empirical data from Hindi/Urdu. This way, the dissertation focuses on cross- linguistic as well as language specific investigation of intervention effects. The third aspect of this dissertation therefore is to relate cross-linguistic variations in intervention effects to the difference in the nature of the phase heads among languages. For instance, the cross-linguistic difference in the properties of various constructions (such as Wh-scope marking and double object construction) is reducible to the availability of an escape hatch with the relevant phase head (C or v). In this exploration, this dissertation also makes two language specific claims about Hindi/Urdu; (a) the basic word order in this language is SVO, and (b) this language involves Wh-movement in overt syntax. The first claim contributes to the long standing debate about the basic word in Hindi/Urdu, a language which shows a dichotomy in its word order by exhibiting both SOV and SVO word order. The second claim adds to the covert vs. overt Wh-movement debate for Wh in-situ languages like Hindi/Urdu. The dissertation attributes both these aspects to the phasehood of little v in Hindi/Urdu.

The purpose of this dissertation is to reconsider reflexives in Japanese through thefollowing three steps: (a) separation of genuine reflexive elements from elements that are confounded as reflexives, (b) classification of reflexive anaphors into subtypes based ontheir semantic difference, and (c) classification of predicates that occur with anaphors. Many researchers have worked on the reflexive element zibun ‘self,’ but Japanese has other reflexive elements as well. These elements including zibun have not only the reflexive anaphor usage but also other ones. All the instances are, however, often lumped together under the category ‘reflexives.’ I distinguish genuine reflexive anaphorsin Japanese from elements that are confounded as reflexive elements, by scrutinizing theirsyntactic and semantic properties and behavioral differences.Further, I claim that reflexive anaphors are classified into two subtypes as ‘Pure reflexive anaphors’ and ‘Near reflexive anaphors’ (Lidz, 1996, 2001a,b) based on theirsemantic property. Observing several languages from different language families, I pro-pose that there is a parametric variation with respect to the two-type distinction of reflex-ive anaphors among languages. In languages like Japanese, anaphors in the form of affixare Pure reflexive anaphors, while non-affixal anaphors are Near reflexive anaphors. On the other hand, in languages like Dutch, the morphological composition (complexity) ofanaphor corresponds to the two-type anaphor distinction. What yields this variation is also discussed. In considering reflexives, it is important to know the nature of reflexive anaphors, but it is also essential to understand the nature of predicates that occur with an anaphor. One of the unsolved questions in the research of reflexives in Japanese is that the anaphor zibun cannot take a local antecedent when it occurs with a certain type of verb, although anaphors should be locally bound. Several studies have demonstrated that the availabil-ity of local binding of an anaphor depends on the property of its cooccuring predicate(Reinhart and Reuland, 1993, Bergeton, 2004, among others). Discussing how the type of reflexive and the type of predicate relate, I propose a way to categorize predicates inJapanese into subtypes based on the analysis in Bergeton (2004). By going through thethree steps, I give an answer to the unsolved question.

This thesis investigates the implications of binding phenomena for the development of a reductionist theory of grammatical dependencies. The starting point is the analysis of binding and control in Hornstein (2001, 2009). A number of revisions are made to this framework in order to develop a simpler and empirically more successful account of binding phenomena. The major development is the rejection of economy-based accounts of Condition B effects. It is argued that Condition B effects derive directly from an anti-locality constraint on A-movement. Competition between different dependency types is crucial to the analysis, but is formulated in terms of a heavily revised version of Reinhart’s (2006) “No Sneaking” principle, rather than in terms of a simple economy preference for local over non-local dependencies. In contrast to Reinhart’s No Sneaking, the condition presented here (“Keeping Up Appearances”) has a phonologically rather than semantically specified comparison set. A key claim of the thesis is that the morphology of pronouns and reflexives is of little direct grammatical import. It is argued that much of the complexity of the contemporary binding literature derives from the attempt to capture the distribution of pronouns and reflexives in largely, or purely, syntactic and semantic terms. The analysis presented in this dissertation assigns a larger role to language-specific “spellout” rules, and to general pragmatic/interpretative principles governing the choice between competing morphemes. Thus, a core assumption of binding theory from LGB onwards is rejected: there is no syntactic theory which accounts for the distribution of pronouns and reflexives. Rather, there is a core theory of grammatical dependencies which must be conjoined withwith phonological, morphological and pragmatic principles to yield the distributional facts in any given language. In this respect, the approach of the thesis is strictly non-lexicalist: there areno special lexical items which trigger certain kinds of grammatical dependency.All non-strictly-local grammatical dependencies are formed via A- or A-chains,and copies in these chains are pronounced according to a mix of universal principles and language-specific rules. The broader goal of the thesis is to furtherthe prospects for a “reductionist” approach to grammatical dependencies alongthese lines. The most detailed empirical component of the thesis is an investigation of the problem posed by binding out of prepositional phrases. Even in a frameworkincorporating sideward movement, the apparent lack of c-command in this con-figuration poses a problem. Chapter 3 attempts to revive a variant of the traditional “reanalysis” hypothesis. This leads to an investigation of certain propertiesof pseudopassivization and preposition stranding. The analyses in this thesis are stated within an informal syntactic framework. However, in order to investigate the precise implications of a particular economy condition, Merge over Move, a partial formalization of this framework is developed in chapter 4. This permits the economy condition to be stated precisely, and in a manner which does not have adverse implications for computational complexity.

This study investigates properties of adjunct control with a particular focus on Turkish providing an analysis for different types of adjunct control structures such as temporal adjunct clauses and purpose clauses, which have been understudied in Turkish linguistics. In analyzing adjunct control structures, I use Agree-based Theory of Control (ATC) (Landau 2000 and 2004) as a theoretical basis. I introduce a new interarboreal operation that I call Interarboreal Agree which draws upon the intuitions of Nunes (1995) that syntactic relations can be established between two unconnected trees. This analysis refines ATC in that ATC in its current form fails to account for Obligatory Control reading in adjunct control structures. An important overarching theme of this dissertation is the role of Aspect in determining control properties of adjunct clauses. As an example, I account for the structures that I call SOC (Subject or Object Control) structures in Turkish temporal adjunct clauses by assuming that these clauses do not have an Aspect Phrase projection. I also argue that Case variation in languages that have morphologically-dependent secondary predicates, that is to say, secondary predicates that agree with the NP they predicate in Case, gender or number, can be explained by the presence or absence of an Aspect Phrase projection. Aspect properties of adjunct clauses come into play in purpose clauses as well. For instance, in English, control in purpose clauses exhibits optionality in terms of the choice of the controller, which is not the case in the Turkish counterpart of the same type of purpose clauses. I argue that this is due to the fact that English purpose clauses do not have an Aspect Phrase projection.

The precise contribution and mechanism of sensory feedback (particularly auditory feedback) in successful speech production is unclear. Some models of speech production, such as DIVA, assert that speech production is based on attempting to produce auditory (and/or somatosensory targets; e.g. Guenther et al. 2006), and thus assign a central role to sensory feedback for successful speech motor control. These models make explicit predictions about the neural basis of speech production and the integration of auditory and somatosensory feedback and predict predict basal ganglia involvement in speech motor control. In order to test the implications of models depending on the integration of sensory feedback for speech, we present neuroimaging studies of two disorders of speech production in the absence of apraxia or dysarthria - one acquired (Foreign Accent Syndrome; FAS) and one developmental (Persistent Developmental Stuttering; PDS). Our results broadly confirm the predictions of the extended DIVA (Bohland et al. 2010) model, and emphasize the importance of the basal ganglia, especially the basal ganglia-thalamic-cortical (BGTC) loops. I argue that FAS should be thought of as a disorder of excessive speech sensory feedback, and that fluency in PDS depends on successful integration of speech sensory feedback with feedforward control commands.