Dissertation Research

The Problem with Cognates in the Bilingual Mental Lexicon

My dissertation is exploring the role of cognates in the bilingual mental lexicon. This project is using Spanish-English bilinguals. Current models of the bilingual mental lexicon assume no shared storage of words across languages. However, special status is given to cognates, words that share form and meaning between languages, which are theorized to share either orthographic or morphemic representations (for a review, see Peeters et al., 2013). Words in the bilingual mental lexicon have previously received binary cognate/non-cognate categorization, based primarily on orthographic overlap. Peeters et al. (2013) recently considered an identical cognate/non-identical cognate distinction. There may further be a graded overlap across the phonological, syntactic, and semantic features of cognates. For example, the English and French cognates for ‘document’ share an identical orthographic representation, but the phonological representations are /dɒkjʊmənt/ and /dɔkymɑ̃/, respectively. If phonological or syntactic features are shared across cognate representations, greater overlap at one or both of these levels should result in lower processing costs. This project will consider the following fundamental questions considering cognate processing: (i) what amount of overlap is perceived by bilinguals, (ii) at what processing levels, (iii) with effects from language backgrounds.

To examine interlanguage influence between cognates in bilinguals’ minds, this project will scrutinize cognate processing at three levels of overlap: (A) complete overlap at the conceptual, syntactic, and phonological levels, (B) complete overlap at the conceptual, and syntactic levels, but phonological differences, and (C) overlap at the conceptual and phonological levels, but differences at the syntactic level. Spanish-English simultaneous and sequential bilinguals will listen to (1) cognates in isolation and (2) cognates intersententially, while response times to word identification and comprehension questions are measured and ERPs recorded. This study aims to develop a model of cognate categorization, the cognate continuum, and test this model against processing patterns demonstrated by advanced bilinguals of different ages of acquisition or acquisition order.

​

I am currently recruiting participants for my norming study. Here is the link for this cognate survey, if you're interested in participating. If you're a Spanish-English bilingual in South Carolina, and are interested in participating in the main study, please email me at dfahey@email.sc.edu.

Mentors: Mila Tasseva-Kurktchieva, Nina Moreno, Anne Bezuidenhout, Dirk-Bart den Ouden

University of South Carolina

Current and Past Projects with the Neurolinguistics Lab

Modulating Vocal Pitch Motor Control through Neurostimulation

High-Definition transcranial Direct Current Stimulation (HD-tDCS) is a technique that stimulates neurons to increase or decrease their excitability. Findings in previous studies have shown that HD-tDCS affects functional behavior and neural plasticity (Kuo et al., 2013; Monti et al., 2013; Malyutina & Den Ouden, 2014), which suggests that it may be effective for improving vocal pitch motor control. Evidence from earlier functional magnetic resonance imaging (fMRI) studies has shown that ventral motor cortex, an area of the brain that controls the movement of speech production muscles, is strongly activated when humans control their voice pitch (Parkinson et al., 2012). Therefore, in this project we aim to study how HD-tDCS of ventral motor cortex can modulate pitch motor control during vocal production.

​

Mentors: Dirk-Bart den Ouden, Roozbeh Behroozmand

Collaborators: Taylor MacDonald, Janelle Rocktashel

University of South Carolina

Asymmetric Binarity as a Cognitive Universal: The Rhythm of Syntactic Structure

This project investigates the overlap in neural support for two basic processes of structure assignment: combining words into phrases and beats into rhythmic units.  What rhythm and grammatical structure have in common is an asymmetry in the hierarchical structure of their elements, known as headedness. In linguistics, this asymmetric hierarchy is represented in syntax as the operation Merge (Chomsky, 1995), in which two elements are combined in a phrasal structure, one element governing the other. In musical theory, asymmetric binarity can be understood through the Generative Theory of Tonal Music (GTTM; Lerdahl & Jackendoff, 1983), in which musical elements are hierarchically ranked, one element having more strength than another. The human mind assigns such rhythmic patterns to strings of beats, a process named ‘beat induction’ (Honing, 2012). If Merge and beat induction have psychological realities that are controlled by the same brain region, this has implications for the autonomy of language as a cognitive domain. Although there is clear evidence of theoretical structural overlap in language and rhythm, the shared cognitive process underlying the two domains is not evident. This study will address this issue through a functional MRI study of participants' brains while processing either rhythmic or linguistic stimuli.

​

This project was a collaboration between me and my adviser in the Neurolinguistics Lab, Dr. Dirk-Bart den Ouden. Together, we researched current data in neuroimaging and theoretical structuring of both musical and linguistic domains. I applied for and received the grant application which funded this project, and completed the IRB application. Under Dr. den Ouden's supervision, I scanned the participants to the study at McCausland Center for Brain Imaging, where I have level 1 scanning clearance.

​

This work was partially supported by a SPARC Graduate Research Grant from the Office of the Vice President for Research at the University of South Carolina.

​

Mentor: Dirk-Bart den Ouden

University of South Carolina

Current and Past Projects with the Second Language Acquisition Lab

Third Language Acquisition of Brazilian Portuguese

This project investigates the acquisition of a third language Portuguese grammatical [gender] and [number] by native English speakers who have previously studied Spanish. This study considers how typology and proficiency affect learning both [gender] and [number] in Brazilian Portuguese. we examine how the similarity of features between languages using the To consider typology, we looked to the Typological Proximity Model (TPM) (Rothman, 2015), which suggests that any prior learned language can be wholesale transferred to the third language if it is determined to be typologically closer. This contrasts with the Scalpel model (Slabakova, 2016), which suggests that learners transfer only the applicable grammatical structure from the typologically similar language. To consider proficiency, we analyzed the Threshold Hypothesis (Cummins, 1979). When interpreted for third language learners, this theory suggests that there are 2 thresholds: learners must attain high intermediate proficiency in both the second and third language for beneficial effects from transfer. Otherwise, the theory holds that L2 knowledge will be detrimental to the learner.

​

Mentor: Mila Tasseva-Kurktchieva

Collaborator: Jefferson De Carvalho Maia

University of South Carolina

Other Research

Korean-English Bilingual Acquisition in Optimality Theory

This project is investigating spontaneous vowel utterances in a case study of a Korean-English bilingual child for interlanguage influence. The phonological framework in consideration is Optimality Theory.

​

Mentor: Eric Holt

Collaborators: Jiyeon Song, Keunhyung Dennis Park

University of South Carolina