Recent publications

I have had the pleasure of collaborating on a number of interesting projects the past few years. Here are some of the papers I have been involved in over the past two years.

Evidence for cognitive and brain reserve supporting executive control of memory in lifelong bilinguals with Alessandra Macbeth, Natsuki Atagi, and Christine Chiarello

This paper examines changes in brain structure in aging and its relationship to bilingualism and executive control. We report on the relationship between gray matter and white matter measures and resistance to proactive interference in younger and older bilinguals and monolinguals and find evidence for both cognitive reserve and brain reserve among older bilinguals.

The neural time-course of American English vowel discrimination by Japanese, Russian, and Spanish second-language learners of English with Valerie Shafer, Sarah Kresh, Kikuyo Ito, Miwako Hisagi, Nancy Vidal-Finnerty, Daniela Castillo, and Winifred Strange

This paper explores difficulties in English vowel discrimination for late bilinguals whose L1 is Spanish, Russian, or Japanese. Using neurophysiological and behavioral data, we found that L1 phonology played a significant role in the ability to contrast spectrally similar L2 vowels with L1 Spanish speakers showing the greatest difficulty.

Perceptual discrimination measure of non-native phoneme perception in early and late Spanish-English and Japanese-English bilinguals with Miwako Hisagi, Mike Zandona, Justin Kent, Daniela Castillo, Ingrid Davidovich, and Valerie Shafer

This is a follow-up study from the previous one (Shafer et al., 2021) that examined L1 Spanish and Japanese speakers’ discrimination abilities for L2 English vowels using an AXB discrimination task. In this study we compared early and late L2 English learners and found that early bilinguals evidenced better L2 vowel discrimination than late bilinguals. We are currently recruiting older adults from the same language groups to look at age-related changes and whether they intersect with language background for L2 speech perception.

The effect of second-language vocabulary on word retrieval in the native language with Seamus Donnelly, Jungmee Yoon, and Loraine Obler

This research investigated whether acquiring new words in a second language leads to interference or facilitation for their L1 translation equivalents. We found evidence for facilitation – when participants had acquired the L2 word, they were faster to retrieve the word’s translation equivalent in the L1 compared to words that they only knew in the L1 (no L2 translation equivalent had been learned).

Demographic effects on longitudinal semantic processing, working memory, and cognitive speed with Jet Vonk, Alexandre Nikolaev, Dalia Cahana-Amitay, Ron Spiro, Martin Albert, and Loraine Obler

This paper shows that age-related declines show different trajectories for language and cognitive tasks. Cognition declined linearly with age while language showed no decline until about 73-74 years of age. Although we found a positive effect of education on both language and cognitive abilities, education did not affect the rate of decline.

Production of inflected novel words in older adults with and without dementia with Alexandre Nikolaev, JungMoon Hyun, Minna Lehtonen, Sameer Ashaie, Merja Hallikainen, Tuomo Hänninen, and Hilkka Soininen

This paper reports on a study of morphological processing by Finnish speakers with mild cognitive impairment or dementia and age-matched healthy controls. The results from a speech elicitation task involving Finnish-conforming pseudo-words revealed that participants used a strategy of phonological resemblance to real words to decide how pseudo-words should be inflected. This supports single-route models of inflection rather than dual-route models.


Student research presentations 2021

Students in the Multilingualism Lab presented their in-progress research projects at the 2021 Virtual Cal State East Bay Student Research Symposium. Their recorded presentations can be found below.

Presentation on Cross-language Treatment Effects in Bilinguals with Aphasia

Bilingual aphasia: This study involved an 8-week naming treatment study of two Spanish-English bilinguals with aphasia. The patients were given treatment in English and were assessed in both English and Spanish in order to investigate whether treatment gains would transfer to the untreated language, Spanish. This is part of Kana Lopez’s Master’s thesis.

Lopez, K., Vasquez, A. S., Soto, J., Tollast, A., Gravier, M., & Higby, E.  Cross-language Treatment Effects in Bilinguals with Aphasia.

Bilingual language development: This study tested 30-32-month-old toddlers from Mandarin-speaking and English-speaking homes to examine the influence of Mandarin on the acquisition of plural and verbal morphology in toddlers exposed to Mandarin and English. This is part of Ogechi Okeke and Jennifer Do’s Master theses.

Okeke, O., Do, J., Higby, E., & Nicholas, K.  Language Development in Mandarin-English Bilingual Toddlers.

Sulcal morphology: This study examines individual differences in brain morphology, particularly the paracingulate sulcus in the anterior cingulate cortex. The length of this sulcus in each hemisphere is being indexed and will be entered into a correlational analysis with cognitive behavioral tasks to examine whether paracingulate length is associated with certain types of cognitive skills.

Sanchez, A., Crosby, M., & Higby, E.  The Significance of Brain Morphology for Cognitive Abilities.

Recruiting Spanish-English bilinguals with aphasia for online treatment study

Flyer_Bilingual aphasia study
One of my students, Kana Lopez, is starting data collection for her Master’s thesis and is recruiting Spanish-English bilinguals with aphasia. The study will be conducted online, so there are no geographical constraints, except that the person should be residing in the U.S.
Kana is running an intensive treatment study and recruiting 2 participants for the study. In addition to 8 weeks of free intensive language therapy, we will be giving participants a small gift card. Please see Kana’s message below. Interested individuals should contact Kana at

My name is Kana Lopez. I am a graduate student at Cal State East Bay in the Speech, Language, and Hearing Sciences Department.

I am conducting a research project for my Master’s thesis about Aphasia and Bilingualism. I am recruiting two Spanish-English bilingual participants who have been diagnosed with aphasia. Below is a brief description of my study.

This study focuses on the impact of language learning environment on recovery from brain injury. The primary goal of the project is to better understand the causes of different recovery patterns in bilingual aphasia and to see how institutional language learning (also known as “explicit”) versus learning in a natural setting, such as at home (also known as “implicit”), impacts the recovery of language in bilinguals with aphasia.

I am looking for two participants who learned Spanish as their first language and learned English second, either in a classroom or naturalistically, and who had a stroke more than 6 months ago that resulted in aphasia.

Participants will receive 8 weeks of free intensive speech-language therapy in English, focusing on naming and sentence formulation. All therapy will be provided via videoconferencing on a computer. Participants will receive a gift card for their participation.

Please feel free to distribute the flyer to potential participants or other professionals. Interested individuals should contact me at

Kana Lopez

Master’s student

California State University, East Bay

Flyer_Bilingual aphasia study

LSA Summer Institute 2019

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The summer is flying by! For most of July, I am hanging out in Davis, California, to teach a course on the Bilingual Brain with Loraine Obler at the Linguistic Society of America Summer Institute. I have found Davis to be absolutely charming, and my daily runs along the Arboretum trail have been a special treat.


We cover a lot of ground in the course, but there is so much great research out there on bilingualism and the brain that we only barely scratch the surface in each class. The students in our class are mostly graduate students and advanced undergraduates, with a few faculty drop-ins as well. I’m really enjoying getting to know them and learning what their interests are in the field of neurolinguistics.

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If you’re at the institute, please say hi!

ISB 2019 presentation on bilingual inhibitory control

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Last week I was in Edmonton, Alberta, Canada to attend the International Symposium on Bilingualism and present some of the research that I have been conducting at UC Riverside with one of my fabulous undergraduate students, Paulina Vasquez-Rocha. The conference was a wonderful place to meet more bilingualism researchers and catch up with old friends.

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In this study, we explored whether bilinguals exhibit proactive or reactive control of the dominant language when naming a block of pictures in the non-dominant language. We found evidence for proactive control, meaning that bilinguals inhibited the language as a whole rather than specific (interfering) lexical items. The full abstract is below.


When bilinguals plan speech in one of their two languages, the other language is active and potentially competing for production. Bilinguals may inhibit the dominant language (L1) to produce words in the non-dominant language (L2) (Misra et al., 2012). In this experiment we asked whether bilinguals inhibit specific words that might interfere in speaking L2 (local inhibition) or whether they inhibit the L1 lexicon as a whole (global inhibition). Two groups of Spanish-English bilinguals completed a picture naming task in which they first named pictures in separate blocks in L1, then L2, then L1. One group named the same pictures across all the blocks. The other group named novel pictures in the L2. If the L1 is inhibited globally, we expect to see the same patterns for both groups. However, if specific items are suppressed, repetition priming for those who named novel pictures in the L2 is expected. In a final block, they named pictures in both languages depending on a cue. In mixed blocks, switching into the L1 is more costly than switching into the L2 (Meuter & Allport, 1999). However, it is unclear from previous research how that inhibition is affected by prior naming. Data from 59 participants suggest that L1 suppression is global. L1 naming was similarly affected by repeated and novel items. Naming in the mixed-language block was slower in English; however, Spanish naming was faster in the mixed block than in the single-language block for repeated pictures. This pattern suggests that naming the same pictures in both languages led to a greater L2 repetition advantage for the language-mixing condition, but no advantage for the L1. Thus, the scope of L1 inhibition is not limited to the specific items retrieved. Instead, bilinguals inhibit the L1 lexicon as a whole when planning L2 speech.


New paper on cognitive control and language production in aging

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Our new article has just been published in the journal Experimental Aging Research. In this study, we investigated the question of whether word finding difficulties among older adults may be partially due to age-related declines in cognitive control. In a sample of 264 cognitively healthy monolingual older adults, we found that individual differences in executive functions predicted word retrieval speed and accuracy on an object-naming and an action-naming test. In particular, mental set-shifting abilities predicted retrieval accuracy on both tests while fluency (sometimes referred to as “efficiency of access to long-term memory”) predicted retrieval speed on both tests and accuracy for object naming.

This work was done with my colleagues from the Language in the Aging Brain lab at the VA Hospital in Jamaica Plain, MA. I am currently conducting a follow-up study at the University of California, Riverside exploring the relation between cognitive control and word retrieval in bilingual and monolingual older adults to elucidate the independent effects of aging and bilingual experience on word retrieval, cognition, and brain structure and function.

The full-text of the article is available here: and on my Publications page.

Student presentations

This past week a bunch of my students presented at three undergraduate research conferences, and they did AMAZING. They’ve been working really hard on various research projects over the past year, and they finally got to show off some of that hard work. Click on the poster titles below to download a copy of their posters!

The Scope of Inhibitory Control in Bilingualism

Paulina Vasquez-Rocha and Abdiel Lopez-Martinez



Paulina gave two oral presentations on her work: one at the UCR Undergraduate Research Symposium and another at the Southern California Undergraduate Linguistics Conference at UCLA. Abdiel presented a poster at the R’PSYC Research Conference at UCR.

*Vasquez-Rocha, P., Higby, E., & Kroll, J. F. (2019, May). The scope of dominant-language inhibition in bilingualism. Southern California Undergraduate Linguistics Conference, Los Angeles, CA.

*Vazquez-Rocha, P., Higby, E., & Kroll, J.F. (2019, May). How do bilinguals plan the language they intend to speak? University of California, Riverside Research Symposium, Riverside, CA.

*Lopez-Martinez, A., Vasquez-Rocha, P., Higby, E., & Kroll, J. F. (2019, May). Inhibition in bilinguals’ language production. R’PSYC Undergraduate Research Conference, Riverside, CA.


Using verbal fluency to understand the impact of language use and self-rated proficiency on lexical access in bilingualism

Charles Lai, Arlyn Ballesteros, Sam King, and Mariam Morkos

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Charles and Arlyn presented their poster at both the UCR Undergraduate Research Symposium and the R’PSYC Undergraduate Research Conference.

*Lai, C., *Ballesteros, A., *King, S., *Morkos, M., Takahesu-Tabori, A., Higby, E., & Kroll, J. F. (2019, May). Using verbal fluency to understand the impact of language use and self-rated proficiency on lexical access in bilingualism. University of California, Riverside Research Symposium, Riverside, CA.


Effects of implicit word retrieval in bilinguals

Monica Martinez, Ziomara Machado, and Daniela Ayon

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Monica and Daniela presented their project at the UCR Undergraduate Research Symposium.

*Martinez, M., *Ayon, D., *Machado, Z., Higby, E., & Kroll, J. F. (2019, May). Effects of implicit word retrieval in bilinguals. University of California, Riverside Research Symposium, Riverside, CA.


Subjective task difficulty in two languages and its effect on task ordering

Guadalupe Mendoza and Samantha Ramos

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Samantha and Guadalupe went to Beijing, China, for two months this past winter to conduct their study on native speakers of Mandarin Chinese. They presented some of their findings from that project at both the UCR Undergraduate Research Symposium and the R’PSYC Undergraduate Conference.

*Mendoza, G., *Ramos, S., Higby, E., & Rosenbaum, D. (2019, May). Subjective task difficulty in two languages and its effect on task ordering. University of California, Riverside Research Symposium, Riverside, CA.


Investigating the relationship between paracingulate sulcus patterns and executive functions

Gold Osita-Ogbonnaya, Madeline Finnegan, Melissa Rico, and Faredun Dungore

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Gold and Madeline presented their project at the R’PSYC Undergraduate Conference.

*Osita-Ogbonnaya, G., *Finnegan, M., *Rico, M., *Dungore, F., Atagi, N., Rupp, M., Macbeth, A., & Higby, E. (2019, May). Investigating the relationship between paracingulate sulcus patterns and executive functions. R’PSYC Undergraduate Research Conference, Riverside, CA.


Understanding the effects of predicción in bilinguals

Jose Calderon, Blanca Bautista, Berenice Velazquez, and Natalia Rzeslawski-Gamboa

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Jose and Blanca presented their project at the UCR Undergraduate Research Symposium.

*Calderon, J., *Bautista, B., *Velazquez, B., *Rzeslawski-Gamboa, N., Higby, E., Zirnstein, M., & Kroll, J. F. (2019, May). Understanding the effects of predicción in bilinguals. University of California, Riverside Research Symposium, Riverside, CA.

New article in Cortex

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My colleagues in Finland and I have published another paper on morphological processing in Finnish, a language with a highly complex morphological system. In this paper we look at how morphological and lexical processing differs for healthy older adults and people with Mild Cognitive Impairment or Alzheimer’s disease, compared to healthy younger adults. The paper is available here:

Individuals with Alzheimer’s disease often show declines in semantics (a word’s meaning). It is unclear whether this semantic decline affects morphological processing. In order to answer this question, we tested to what degree word recognition in Finnish was influenced by semantic and form-based (spelling) factors and how the reliance on these factors changes with age and with neuropathology. In line with previous research on Alzheimer’s disease, we found decreased reliance on semantic aspects of word recognition for these patients. However, what was particularly interesting in this study was that healthy older adults and individuals with Mild Cognitive Impairment showed similar patterns to what was found for patients with Alzheimer’s. In other words, all three of the older adult groups showed greater reliance on form-based factors for word recognition than younger adults.

Full abstract:

Reading a word activates morphologically related words in the mental lexicon. People with Alzheimer’s disease (AD) or Mild Cognitive Impairment (MCI) often have difficulty retrieving words, though the source of this problem is not well understood. To better understand the word recognition process in aging and in neurodegenerative disorders such as MCI and AD, we investigated the nature of the activation of morphologically related family members in 22 Finnish speakers with AD, 24 with MCI, and 17 cognitively healthy elderly. We presented Finnish monomorphemic (base form) nouns in a single-word lexical decision experiment to measure the speed of word recognition and its relation to morphological and lexical variables. Morphological variables included morphological family size (separate for compounds and derived words) and pseudo-morphological family size (including the set of words that have a partially overlapping form but that do not share an actual morpheme, e.g., pet and carpet, or corn and corner). Pseudo-morphological family size was included to examine the influence of words with orthographic (or phonological) overlap that are not semantically related to the target words. Our analyses revealed that younger and elderly controls and individuals with MCI or AD were influenced by true morphological overlap (overlapping forms that also share meaning), as well as by the word’s pseudo-morphological family. However, elderly controls and individuals with MCI or AD seemed to rely more on form overlap than young adults. This demonstrates that an increased reliance on form-based aspects of language processing in Alzheimer’s disease is not necessarily due to a partial loss of access to semantics, but might be explained in part by a common age-related change of processes in written word recognition.

Psychonomics and CAMP


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Fall is always full of conference-going. It’s an exciting time to share some of your latest findings and get feedback on projects that are in progress. It’s also very stimulating – cool new research happening everywhere, catching up with old friends and networking with others.

This year I presented some research at the annual meeting of the Psychonomic Society in New Orleans, LA, and at the California Meeting on Psycholinguistics at the University of Southern California in Los Angeles.

The project that I presented on at this meeting is an analysis that I have been working on with three research assistants in New York. We have been analyzing verbal fluency data from Spanish-English bilinguals in New York City. These bilinguals completed semantic and phonemic fluency tasks in both Spanish and English. We are analyzing their data in order to gain insight into their lexical organization and/or their lexical access. We are comparing their data to two control groups: English monolinguals and Spanish monolinguals (actually, native Spanish speakers with limited English proficiency) living in New York City. In order to characterize their performance, we are looking at number of words produced, average lexical frequency of the words they produced (in other words, are the words mostly highly frequent words in the language or do they also dig into their low-frequency vocabulary?), as well as the percent of words produced that are cognates. Cognates are words that overlap in both form and meaning in two languages, like bicycle and bicicleta in English and Spanish.

What we have found so far is that highly proficient Spanish-English bilinguals produced just as many words during the Spanish trials as Spanish controls and the words they produced were about the same level of word frequency. We included both early and late bilinguals, so this group included bilinguals who were born and raised in New York. However, there were some group differences for English trials. Early bilinguals showed the same patterns as English controls. However, late bilinguals produced fewer responses than English controls on the semantic fluency task and their responses were higher frequency (on average). Late bilinguals also produced a higher proportion of cognate on the phonemic task in English. Interestingly, the early bilinguals were in between the English controls and late bilinguals on all of these measures, suggesting more of a graded effect than a strict difference for late bilinguals.

We also investigated the characteristics of responses given over the course of the trial. Typically, responses in the beginning of the trial are high-frequency and responses decrease in frequency as the speaker searches deeper and deeper into their lexicon for exemplars. An odd pattern that we observed was that early bilinguals did not show this characteristic pattern on the phonemic fluency task. Their responses showed no relationship between frequency and response number (which was used to represent the time course). We are currently investigating why this pattern shows up for the early bilinguals by looking at some background variables that may differentiate them from late bilinguals or may produce interesting variability within the group.

You can find copies of the Psychonomics poster and the CAMP presentation on my ResearchGate profile:

UCR Aging Initiative

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An exciting new development at UCR! UC Riverside is launching an Aging Initiative aimed at bringing together various types of research on aging that are going on around campus. This is a great opportunity for researchers to collaborate across disciplines to study aging and to consider the various facets of the aging process from the psychological to the biological and the social realms. We will be hosting a half-day workshop on November 27th to share ideas about how to develop this initiative and work across disciplines.