Background: The most common cause of aphasia is a left middle cerebral artery stroke affecting the left perisylvian region of the brain. The perisylvian region is critical for supporting phonological processing, and damage to this region results in difficulty with retrieving and manipulating speech sounds. The impact of weakened phonology has been…

Adult learners of a new language (L2) tend not to achieve target-like knowledge and performance, so the cognitive status of L2s has long been debated. While monolingual native (L1) speakers robustly apply their grammatical knowledge to input as it unfolds, there are competing claims about whether L2 speakers also do so reflexively (Dekydtspotter,…

Bilinguals are able to compose expressions across their languages with seeming ease. This phenomenon, commonly referred to as "code-switching," has challenged both theoretical models in linguistics as well as neurobiological models of language processing. And yet, our models of the bilingual brain and the language processing mechanism…

This dissertation investigates how parametric variation of linguistic properties leads to similarities and differences in language processing across the levels of words, grammatical features, and sentences. For a truly generalizable theory of psycholinguistics, the languages surveyed should not be constrained to English (Garnham, 1994; Norcliffe…

Data-driven learning uncontroversially plays a role in human language acquisition--how large a role is a matter of much debate. The success of artificial neural networks in NLP in recent years calls for a re-evaluation of our understanding of the possibilities for learning grammar from data alone. This dissertation argues the case for using…

Primary progressive aphasia (PPA) is an acquired neurodegenerative syndrome that has specific and devastating effects on an individual's speech and language ability. Based on a detailed assessment of behavior and cognition, combined with structural neuroimaging data and pathological evidence, PPA is typically classified into three variants: the…

Learning new languages is a complex task involving both explicit and implicit processes (i.e., that do/do not involve awareness). Understanding how these processes interact is essential to a full account of second language (L2) learning, but accounts vary as to whether explicit processes help (e.g., DeKeyser, 2007), hinder (e.g., Ellis &…

The representational product of sentence comprehension is the result of the interplay between episodic and semantic memory and our knowledge of the grammatical devices of our language which guide how we retrieve information from these systems. Past participles, being a part of speech derived from verbs but used in a prenominal position (e.g. words…

The topic of this dissertation concerns the ways that (IN)ANIMACY distinctions interact with various sub-systems of the human language faculty, in particular, morpho-syntax. In Modern Standard Arabic (MSA), morpho-syntax and ANIMACY can be pit against each other directly on the same set of target words, allowing a close inspection of the…

Recent research has shown that distinct event-related potential (ERP) signatures are associated with switching between languages compared to switching between dialects or registers (e.g., Khamis-Dakwar & Froud, 2007; Moreno, Federmeier & Kutas, 2002). The current investigation builds on these findings to examine whether contrastive and…

This thesis investigates the syntactic status of adjectives in Spanish through a crossdisciplinary perspective, incorporating methodologies from both theoretical linguistics and neurolinguistics, specifically, event-related potentials (ERPs). It presents conflicting theories about the syntax of adjectives and explores the ways that the processing…

This study investigated bilingual advantages at additional languages learning by comparing early, highly proficient bilinguals to monolinguals' learning of an additional language in adulthood. The study used both behavioral and neurocognitive measures (event-related potentials) and tested subjects along the trajectory of learning from low to high…

This study used ERP (event-related potentials) to examine both the role of the L1 and the role of individual differences in the processing of agreement violations. Theories of L2 acquisition differ with regard to whether or not native-like acquisition of L2 features is possible (Schwartz and Sprouse, 1994, 1996; Tsimpli and Mastropavlou, 2007),…

This dissertation investigates the neural and behavioral correlates of grammatical agreement computation during language comprehension in native English speakers and highly advanced L1 Spanish-L2 English bilinguals. In a series of electrophysiological (event-related brain potential (ERP)) and behavioral (acceptability judgment and self-paced…

A basic challenge for research into the neurobiology of language is understanding how the brain combines words to make complex representations. Linguistic theory divides this task into several computations including syntactic structure building and semantic composition. The close relationship between these computations, however, poses a strong…