Research

I use behavioral (eye-tracking, response time/accuracy), neuroimaging (EEG, fMRI), and neuromodulation (TMS) methods to study the neural and cognitive bases of auditory comprehension. I am particularly interested in understanding how sociolinguistic variation impacts language processing. My work takes two approaches to variation. The first approach focuses on high-level differences in experience with multiple dialects or languages. The second approach focuses on low-level variability in the acoustic signal, with an emphasis on accented speech. I am currently developing a new line of research in this second area that combines basic cognitive neuroscience research and clinically meaningful measures of adult hearing care. The key question guiding my work is: What makes someone a good listener?

Variation in language experience

Cross-dialectal communication

Long-term experience with a particular dialect makes processing faster, more accurate, and less effortful; however, this familiarity benefit does not always extend to non-standard varieties. I have investigated the effects of dialect familiarity and social markedness in several EEG/ERP studies comparing two types of listeners: listeners from a Southern US English (SUSE) background and listeners from a Mainstream US English (MUSE) background. Regardless of listener background (Mainstream, Southern), environment (university, community), modality (audio only, audio-visual), or stimulus type (word, sentence), we have found that MUSE is easier to process than SUSE. Overall, my work on dialectal variation in syntax and phonetics has shown that standard language ideology outweighs familiarity during processing.

Cross-language activation

Bilingual speech comprehension involves competition between neighboring words in two languages. The degree of cross-language activation is related to the degree of overlap between the two languages; however, cross-language similarity becomes more difficult to define as more levels of the language hierarchy are considered. To solve this problem, I took the lead on a theoretical article that conceptualized the bilingual lexicon as a multilayer network that could model phonological, semantic, and syntactic information simultaneously. The ability to control co-activation is also influenced by relative proficiency. I have investigated the effects of language dominance in several studies, including a study that translated network science and lab-based behavioral methods to a fieldwork setting in rural Colombia. Across studies, I have focused on bilingual speakers of Spanish. This line of work has shown that dominance in the target language helps listeners manage competition during auditory word and sentence processing.

Variation in the speech signal

Adaptation to accented speech

The speech signal varies systematically between utterances, individuals, and social groups within any given language variety. In my NSF-funded doctoral dissertation, I focused on systematic variation arising from the influence of a talker’s first language (L1) on the production of their second (L2). Across studies, I found that exposure to particular Spanish-accented English features facilitated word recognition by reducing competition at the acoustic-phonetic level. This work addressed timely questions in the speech perception literature about the role of variability during exposure to a talker or L2 accent.

Individual differences in phonetic sensitivity

As a postdoctoral researcher, I have continued my work on variation in the speech signal, with a focus on individual differences in perception. In a recent study with younger and older adult listeners, I used eye-tracking to show that individuals vary in their representations of phonetic categories. I am currently extending this line of work to functional language outcomes like speech-in-speech comprehension in bilingual listeners and L2-accented speech comprehension in older adults. Related research has used TMS and fMRI to show that listeners distinguish individual talkers by tracking acoustic information in the speech signal. Together, this work has shown that efficient bottom-up processing is essential for identifying both who is speaking and what is being said.

Future directions

Moving forward, I plan to extend my work on socioindexical variation by integrating listener-related variation (age-related hearing loss) with signal-related variation (complex listening situations) to inform more holistic assessment and intervention strategies for adult hearing care. Older adults frequently report difficulties understanding speech in complex listening situations (e.g. noise, accented speech); however, the underlying causes of these difficulties are not yet understood. The main practical limitation is that the primary clinical measure of hearing loss does not predict real-world comprehension outcomes. While some individuals with age-related hearing loss perform well in complex listening situations, others with normal hearing thresholds struggle. This dissociation between audiological assessment and everyday listening highlights a critical gap in translational hearing research. My goal is to define the individual differences in perceptual, cognitive, and linguistic skill that bridge this gap.