Tamar H Gollan

University of California, San Diego | UCSD · Department of Psychiatry

Proper names are especially prone to retrieval failures and tip-of-the-tongue states (TOTs)—a phenomenon wherein a person has a strong feeling of knowing a word but cannot retrieve it. Current research provides mixed evidence regarding whether related names facilitate or compete with target-name retrieval. We examined this question in two experimen...

Introduction: Evidence on the onset of naming deficits in Alzheimer's disease (AD) is mixed. Some studies showed an early decline, but others did not. The present study introduces evidence from a novel naming test. Methods: Cognitively normal (n = 138), mild cognitive impairment (MCI; n = 21), and Alzheimer's disease (AD; n = 31) groups complete...

Objectives: The present study examined if disruption of serial position effects in list recall could serve as an early marker of Alzheimer's disease (AD) in Spanish-English bilinguals. Methods: We tested 20 participants initially diagnosed as cognitively normal or with mild cognitive impairment who declined and eventually received a diagnosis of...

Objective: This study examined the joint consequences of bilingualism and Alzheimer's disease (AD) for picture naming ability to determine which language is more affected by AD and what scoring methods best distinguish patients from controls. Method: Sixty-five Spanish-English bilinguals including 26 with dementia and 39 controls with equivalent...

Theories of speech production have proposed that in contexts where multiple languages are produced, bilinguals inhibit the dominant language with the goal of making both languages equally accessible. This process often overshoots this goal, leading to a surprising pattern: better performance in the nondominant vs. dominant language, or reversed lan...

Individuals with mild dementia or mild cognitive impairment (MCI) due to Alzheimer’s disease (AD) often have verbal fluency deficits with greater impairment in generating exemplars from a semantic category (e.g., “animals”) than words that begin with a particular letter (e.g., ‘F’). This may reflect early development of pathology in cortical region...

Background The present study aimed to determine if Alzheimer’s disease (AD) affects bilinguals’ ability to name pictures in both languages equally, and to determine what testing procedures best distinguish bilingual patients from controls. Method Sixty Spanish‐English bilinguals, including 19 with dementia and 41 controls with equivalent age, educ...

Spanish-English (Experiments 1–2) or Chinese-English (Experiment 3) bilinguals described arrays of moving pictures in English that began with a complex or a simple phrase (e.g., “[The shoe and the mesa/桌子] moved above the cloud” vs. “[The shoe] moved above the mesa/桌子 and the cloud”). Bilinguals were trained to name the second picture in English fo...

Objective: The present study investigated cognitive mechanisms underlying the ability to stop "autocorrect" errors elicited by unexpected words in a read-aloud task, and the utility of autocorrection for predicting Alzheimer's disease (AD) biomarkers. Method: Cognitively normal participants (total n = 85; n = 64 with cerebrospinal fluid [CSF] bi...

Spanish–English bilinguals switched between naming pictures in one language and either reading-aloud or semantically classifying written words in both languages. When switching between reading-aloud and picture-naming, bilinguals exhibited no language switch costs in picture-naming even though they produced overt language switches in speech. Howeve...

How do bilingual speakers represent and use information that guides the assembly of the words into phrases and sentences (i.e., sentence structures) for languages that have different word orders? Cross-language syntactic priming effects provide mixed evidence on whether bilinguals access sentence structures from both languages even when speaking ju...

Objectives The present study examined if time-pressured administration of an expanded Multilingual Naming Test (MINT) would improve or compromise assessment of bilingual language proficiency and language dominance. Methods Eighty Spanish–English bilinguals viewed a grid with 80 MINT-Sprint pictures and were asked to name as many pictures as possib...

Inhibitory control is thought to play a key role in how bilinguals switch languages and may decline in aging. We tested these hypotheses by examining age group differences in the reversed language dominance effect—a signature of inhibition of the dominant language that leads bilinguals to name pictures more slowly in the dominant than the nondomina...

When producing connected speech, bilinguals often select a default-language as the primary force driving the utterance. The present study investigated the cognitive mechanisms underlying default language selection. In three experiments, Spanish-English bilinguals named pictures out of context, or read aloud sentences with a single word replaced by...

The present study examined task order, language, and frequency effects on list memory to investigate how bilingualism affects recognition memory. In Experiment 1, 64 bilinguals completed a recognition memory task including intermixed high and medium frequency words in English and another list in Spanish. In Experiment 2, 64 bilinguals and 64 monoli...

Applied linguistic work claims that multilinguals’ non-native languages interfere with one another based on similarities in cognitive factors like proficiency or age of acquisition. Two experiments explored how trilinguals regulate control of native- and non-native-language words. Experiment 1 tested 46 Dutch–English–French trilinguals in a monitor...

The current study examined the reliability and consistency of switching and mixing costs in the language and the color-shape tasks in three pre-existing data sets, to assess whether they are equally well suited for the study of individual differences. Specifically, we considered if the language task is as reliable as the color-shape task - an impor...

People frequently gesture when a word is on the tip of their tongue (TOT), yet research is mixed as to whether and why gesture aids lexical retrieval. We tested three accounts: the lexical retrieval hypothesis, which predicts that semantically related gestures facilitate successful lexical retrieval; the cognitive load account, which predicts that...

Objective: We aimed to investigate whether or not demographically-corrected test scores derived from the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) would be less accurate if applied to Spanish-speakers with various degrees of English fluency. Spanish-English Method: One hundred and seventy primarily Spanish-sp...

In the picture-word interference (PWI) task, semantically related distractors slow production, while translation-equivalent distractors speed it, possibly implying a language-specific bilingual production system [Costa, A., Miozzo, M., & Caramazza, A. (1999). Lexical selection in bilinguals: Do words in the bilingual's two lexicons compete for sele...

When naming pictures in mixed-language blocks, bilinguals sometimes exhibit reversed language dominance effects. These have been attributed to proactive inhibitory control of the dominant language, or adaptation of language-specific selection thresholds. Even though reversed dominance arguably provides the most striking evidence of inhibition, few...

The present study examined the effects of aging and CSF biomarkers of Alzheimer's disease (AD) on the ability to control production of unexpected words in connected speech elicited by reading aloud. Fifty-two cognitively healthy participants aged 66-86 read aloud 6 paragraphs with 10 malapropisms including 5 on content words (e.g., "window cartons"...

When switching languages, bilinguals recruit a language control network that overlaps with brain regions known to support general cognitive control, but it is unclear whether these same regions are recruited in passive comprehension of language switches. Using fMRI with a blocked design, 24 Spanish-English bilinguals silently read 36 paragraphs in...

Bilinguals are remarkable at language control-switching between languages only when they want. However, language control in production can involve switch costs. That is, switching to another language takes longer than staying in the same language. Moreover, bilinguals sometimes produce language intrusion errors, mistakenly producing words in an uni...

We examined if bilinguals of two different language combinations can rely on novel and arbitrary cues to facilitate switching between languages in a read-aloud task. Spanish-English (Experiment 1) and Hebrew-English (Experiment 2) bilinguals read aloud mixed-language paragraphs, known to induce language intrusion errors (e.g., saying el instead of...

Objective: The current study investigated how Alzheimer's disease (AD) affects production of speech errors in reading-aloud of mixed-language passages with language switches on cognates (e.g., family/familia), noncognates (e.g., people/gente), and function words (the/la). Method: Twelve Spanish-English bilinguals with AD and 22 controls read-alo...

Tip-of-the-tongue (TOT) states often entail a phenomenological sense that retrieval is blocked, but incomplete activation is more commonly assumed as the underlying mechanism. Bilinguals have more TOTs than mono-linguals, and commonly report that one language feels less accessible after immersion in another although evidence for this is minimal. Kr...

Structural adaptations in brain regions involved in domain-general cognitive control are associated with life-long bilingualism and may contribute to the executive function advantage of bilinguals over monolinguals. To the degree that these adaptations support bilingualism, their disruption by Alzheimer's disease (AD) may compromise the ability to...

Objective. The present study investigated the ability of the Multilingual Naming Test (MINT), a picture naming test recently added to the National Alzheimer’s Coordinating Center’s (NACC) Uniform Data Set neuropsychological test battery, to detect naming impairment (i.e., dysnomia) across stages of Alzheimer’s disease (AD). Method. Data from the...

When spoken language (unimodal) bilinguals switch between languages, they must simultaneously inhibit 1 language and activate the other language. Because American Sign Language (ASL)-English (bimodal) bilinguals can switch into and out of code-blends (simultaneous production of a sign and a word), we can tease apart the cost of inhibition (turning...

This study investigated the effects of the amount of cumulative heritage language (HL) exposure during three time periods, on heritage and majority language performance in young adulthood, among two distinct groups of immigrant populations in the USA. Within each time period, exposure from three different sources were examined, and amount of cumula...

This study aimed to determine if patterns of neuropsychological deficits, vascular risk factors, and neuropathology differ in Hispanic and Non-Hispanic patients with autopsy-confirmed Alzheimer's disease (AD). Participants were enrolled in a longitudinal study at the Shiley-Marcos AD Research Center at the University of California, San Diego. Hispa...

Bilinguals occasionally produce language intrusion errors (inadvertent translations of the intended word), especially when attempting to produce function word targets, and often when reading aloud mixed-language paragraphs. We investigate whether these errors are due to a failure of attention during speech planning, or failure of monitoring speech...

The current study investigated how aging affects production and self-correction of errors in connected speech elicited via a read aloud task. Thirty-five cognitively healthy older and 56 younger participants read aloud 6 paragraphs in each of three conditions increasing in difficulty: (a) normal, (b) nouns-swapped (in which nouns were shuffled acro...

The current study examined the cognitive mechanisms underlying task and language switching by comparing them with each other, and with flanker task performance, at multiple points of the response time distribution. Ninety-eight Spanish-English bilinguals completed cued language and color-shape switching tasks, and 2 versions of a nonlinguistic flan...

Objective: To characterize the hemispheric processing of metaphors in bilinguals compared with monolinguals and to determine the role of language proficiency in hemispheric lateralization. Method: Fifty-seven English-dominant Spanish-English bilinguals and 57 English speaking monolinguals participated in a divided visual field study. The two gro...

Self-ratings of language proficiency are ubiquitous in research on bilingualism, but little is known about their validity, especially when the same scale is used across different types of bilinguals. Self-ratings and picture naming data from 1044 Spanish–English and 519 Chinese–English bilinguals were analyzed in five between- and within-population...

The current study investigated the contribution of phonology to bilingual language control in connected speech. Speech production was elicited by asking Mandarin–English bilinguals to read aloud paragraphs either in Chinese or English, while six words were switched to the other language in each paragraph. The switch words were either cognates or no...

Subjective cognitive decline (SCD) is common in older adults and may be an early marker of future cognitive decline. Research suggest that SCD is more closely related to concurrent symptoms of depression than to objective cognitive performance in non-Hispanic Whites, but it is unknown whether the associations of SCD, cognition, and depression manif...

It is commonly assumed that bilinguals enable production in their nondominant language by inhibiting their dominant language temporarily, fully lifting inhibition to switch back. In a re-analysis of data from 416 Spanish-English bilinguals who repeatedly named a small set of pictures while switching languages in response to cues, we separated trial...

Objective Bilingual healthy adults have been shown to exhibit an advantage in executive functioning (EF) that is associated with microstructural changes in white matter (WM) networks. Patients with temporal lobe epilepsy (TLE) often show EF deficits that are associated with WM compromise. In this study, we investigate whether bilingualism can incre...

The current study investigated the hypothesis that cognates (i.e., translation equivalents that overlap in form, e.g., lemon is limón in Spanish) facilitate language switches. Spanish-English bilinguals were cued to switch languages while repeatedly naming pictures with cognate versus noncognate names in separate (Experiment 1) or mixed (Experiment...

The current study investigated the possibility that language switches could be relatively automatically triggered by context. Single-word switches, in which bilinguals switched languages on a single word in midsentence and then immediately switched back, were contrasted with more complete whole-language switches, in which bilinguals completed a ful...

Bilingual language switching may increase general switching efficiency, but the evidence on this question is mixed. We hypothesized that group differences in switching might be stronger at a long cue-target interval (CTI), which may better tap general switching abilities (Yehene & Meiran, 2007). Eighty Spanish-English bilinguals and 80 monolinguals...

Bilinguals rarely produce unintended language switches, which may in part be because switches are detected and corrected by an internal monitor. But are language switches easier or harder to detect than within-language semantic errors? To approximate internal monitoring, bilinguals listened (Experiment 1) or read aloud (Experiment 2) stories, and d...

Though bilinguals know many more words than monolinguals, within each language bilinguals exhibit some processing disadvantages, extending to sublexical processes specifying the sound structure of words (Gollan & Goldrick, Cognition, 125(3), 491–497, 2012). This study investigated the source of this bilingual disadvantage. Spanish–English bilingual...

The current study investigated the roles of grammaticality and executive control on bilingual language selection by examining production speed and failures of language control, or intrusion errors (e.g., saying el instead of the), in young and aging bilinguals. Production of mixed-language connected speech was elicited by asking Spanish–English bil...

The present study examined the extent to which word production and recognition rely on shared representations in lexical access by examining cross-modality transfer effects and frequency effects in a training paradigm. Participants were trained in reading high- and low-frequency words in a lexical decision task and were subsequently tested in produ...

We investigated age-related decline of bilingual language control. Thirteen older and 13 younger bilinguals performed a verbal fluency task (completing the same letter and semantic categories in each language and switching languages after every category), and a non-linguistic flanker task. In letter fluency, bilinguals produced fewer correct respon...

How do bilinguals switch easily between languages in everyday conversation, when thousands of studies have found that switching slows responses? Previous research has not considered that although switches may happen for different reasons, only some switches – including those typically studied in laboratory experiments – might be costly. Using a rep...

The commentaries on our Keynote article “Psycholinguistic, cognitive, and neural implications of bimodal bilingualism” were enthusiastic about what can be learned by studying bilinguals who acquire two languages that are understood via distinct perceptual systems (vision vs. audition) and that are produced with distinct linguistic articulators (the...

This study investigated the relationship between bilingualism and task switching ability using a standardized measure of switching and an objective measure of bilingual language proficiency. Heritage Language (HL) speaking Spanish-English and Mandarin-English bilinguals and English speaking monolinguals completed all four subtests of the Color-Word...

Bimodal bilinguals, fluent in a signed and a spoken language, exhibit a unique form of bilingualism because their two languages access distinct sensory-motor systems for comprehension and production. Differences between unimodal and bimodal bilinguals have implications for how the brain is organized to control, process, and represent two languages....

The current study contrasted cued versus voluntary switching to investigate switching efficiency and possible sharing of control mechanisms across linguistic and nonlinguistic domains. Bilinguals switched between naming pictures in Spanish versus English or between reading numbers aloud versus adding their digits, either without or with repetition...

Acquiring a heritage language (HL), a minority language spoken primarily at home, is often a major step toward achieving bilingualism. Two studies examined factors that promote HL proficiency. Chinese-English and Spanish-English undergraduates and Hebrew-English children named pictures in both their languages, and they or their parents completed la...

In this study, we investigated dual-language decline in non-balanced bilinguals with probable Alzheimer's disease (AD) both longitudinally and cross-sectionally. We examined patients' naming accuracy on the Boston Naming Test (BNT: Kaplan et al., 1983) over three testing sessions (longitudinal analysis) and compared their performance to that of mat...

Bilinguals experience more tip-of-the-tongue (TOT) states than monolinguals, but it is not known if this is caused in part by access of representations from both of bilinguals' languages, or dual-language activation. In two translation priming experiments, bilinguals were given three Spanish primes and produced either semantically (Experiment 1) or...

Studies have shown reduced Stroop interference in bilinguals compared to monolinguals defined dichotomously, but no study has explored how varying degrees of second language fluency, might affect linguistic inhibitory control in the first language. We examined effects of relative English fluency on the ability to inhibit the automatic reading respo...

Bilinguals rarely produce words in an unintended language. However, we induced such intrusion errors (e.g., saying el instead of he) in 32 Spanish-English bilinguals who read aloud single-language (English or Spanish) and mixed-language (haphazard mix of English and Spanish) paragraphs with English or Spanish word order. These bilinguals produced l...

This study examines the convergence and divergence between subjective and objective measures of language proficiency for assessing language dominance in Mandarin–English bilinguals. Sixty-two young adults (Experiment 1) and 27 children (Experiment 2) provided self-ratings of proficiency level (or were rated by their parents), were interviewed for s...

Bilingual speakers access individual words less fluently, quickly, and accurately than monolinguals, particularly when accessing low-frequency words. Here we examined whether the bilingual speech production disadvantage would (a) extend to full sentences above and beyond single word retrieval and whether it would be modulated by (b) structural freq...

We investigated the relationship between language control and executive control by testing three groups of bilinguals (104 participants) and 54 monolinguals in a training and transfer paradigm. Participants practiced either a language or a non-linguistic color/shape switching task and were tested one week later on both tasks. The color-shape task p...

Second language (L2) instruction programs often ask learners to repeat aloud words spoken by a native speaker. However, recent research on retrieval practice has suggested that imitating native pronunciation might be less effective than drill instruction, wherein the learner is required to produce the L2 words from memory (and given feedback). We c...

The current study investigated the scope of bilingual language control differentiating between whole-language control involving control of an entire lexicon specific to 1 language and lexical-level control involving only a restricted set of recently activated lexical representations. To this end, we tested 60 Dutch-English (Experiment 1) and 64 Chi...

Objective: To investigate which neuropsychological tests predict eventual progression to Alzheimer's disease (AD) in both Hispanic and non-Hispanic individuals. Although our approach was exploratory, we predicted that tests that underestimate cognitive ability in healthy aging Hispanics might not be sensitive to future cognitive decline in this cu...

The current study explored the picture naming performance of patients with Alzheimer's disease (AD). First, we evaluated the utility of the Multilingual Naming Test (MINT; Gollan et al., 2011), which was designed to assess naming skills in speakers of multiple languages, for detecting naming impairments in monolingual AD and amnestic mild cognitive...

The frequency-lag hypothesis proposes that bilinguals have slowed lexical retrieval relative to monolinguals and in their nondominant language relative to their dominant language, particularly for low-frequency words. These effects arise because bilinguals divide their language use between 2 languages and use their nondominant language less frequen...

The current study investigated whether bilingualism affects the processing of sub-lexical representations specifying the sound structure of words. Spanish-English bilinguals, Mandarin-English bilinguals, and English-only monolinguals repeated English tongue twisters. Twister materials had word or nonword targets (thus varying in whether lexical inf...

Bilinguals who are fluent in American Sign Language (ASL) and English often produce code-blends - simultaneously articulating a sign and a word while conversing with other ASL-English bilinguals. To investigate the cognitive mechanisms underlying code-blend processing, we compared picture-naming times (Experiment 1) and semantic categorization time...

This study investigated correspondence between different measures of bilingual language proficiency contrasting self-report, proficiency interview, and picture naming skills. Fifty-two young (Experiment 1) and 20 aging (Experiment 2) Spanish–English bilinguals provided self-ratings of proficiency level, were interviewed for spoken proficiency, and...

The current study tested the hypothesis that bilinguals rely on domain-general mechanisms of executive control to achieve language control by asking if linguistic and nonlinguistic switching tasks exhibit similar patterns of aging-related decline. Thirty young and 30 aging bilinguals completed a cued language-switching task and a cued color-shape s...

The present study uses tip-of-the-tongue (TOT) states as a unique source of evidence to test the hypothesis of lexical access benefits for homophones--that is, whether low-frequency homophones, such as tee, inherit the lexical access benefits of their high-frequency homophonic counterparts, such as tea. We compared retrieval success rates for low-f...

The present study aimed to examine if bilingualism affects executive functions and verbal fluency in Marathi and Hindi, two major languages in India, with a considerable cognate (e.g., activity is actividad in Spanish) overlap. A total of 174 native Marathi speakers from Pune, India, with varying levels of Hindi proficiency were administered tests...

The current study investigated the relationship between bilingual language proficiency and onset of probable Alzheimer's disease (AD) in 44 Spanish-English bilinguals at the UCSD Alzheimer's Disease Research Center. Degree of bilingualism along a continuum was measured using Boston Naming Test (BNT) scores in each language. Higher degrees of biling...

Bilinguals outperform monolinguals on measures of executive control, but it is not known how bilingualism introduces these advantages. To address this question, we investigated whether language-control failures increase with aging-related declines in executive control. Eighteen younger and 18 older Spanish-English bilinguals completed a verbal-flue...

Bilingual advantages in executive control tasks are well documented, but it is not yet clear what degree or type of bilingualism leads to these advantages. To investigate this issue, we compared the performance of two bilingual groups and monolingual speakers in task-switching and language-switching paradigms. Spanish-English bilinguals, who report...

Better tools for assessing cognitive impairment in the early stages of Alzheimer's disease (AD) are required to enable diagnosis of the disease before substantial neurodegeneration has taken place and to allow detection of subtle changes in the early stages of progression of the disease. The National Institute on Aging and the Alzheimer's Associati...

To contrast mechanisms of lexical access in production versus comprehension we compared the effects of word frequency (high, low), context (none, low constraint, high constraint), and level of English proficiency (monolingual, Spanish-English bilingual, Dutch-English bilingual) on picture naming, lexical decision, and eye fixation times. Semantic c...

To investigate the possibility that knowledge of two languages influences the nature of semantic representations, bilinguals and monolinguals were compared in a word association task. In Experiment 1, bilinguals produced less typical responses relative to monolinguals when given cues with a very common associate (e.g., given bride, bilinguals said...

We investigated the consequences of bilingualism for verbal fluency by comparing bilinguals to monolinguals, and dominant versus non-dominant-language fluency. In Experiment 1, bilinguals produced fewer correct responses, slower first response times and proportionally delayed retrieval, relative to monolinguals. In Experiment 2, similar results wer...

The current study tested the assumption that bilinguals with dementia regress to using primarily the dominant language. Spanish-English bilinguals with probable Alzheimer's disease (AD; n=29), and matched bilingual controls (n=42) named Boston Naming Test pictures in their dominant and nondominant languages. Surprisingly, differences between patien...