Tamar H. Gollan

Good Language-Switchers are Good Task-Switchers: Evidence from Spanish-English and Mandarin-English Bilinguals

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 reported switching between languages frequently in daily life, exhibited smaller task-switching costs than monolinguals after controlling for between-group differences in speed and parent education level. By contrast, Mandarin-English bilinguals, who reported switching languages less frequently than Spanish-English bilinguals, did not exhibit a task-switching advantage relative to monolinguals. Comparing the two bilingual groups in language-switching, Spanish-English bilinguals exhibited smaller costs than Mandarin-English bilinguals, even after matching for fluency in the non-dominant language. These results demonstrate an explicit link between language-switching and bilingual advantages in task-switching, while also illustrating some limitations on bilingual advantages.

Tip-of-the-tongue states in Hebrew–English bilinguals.

Tip-of-the-tongue states (TOTs) in proficient Hebrew–English bilinguals were compared to those of age-matched monolinguals. Monolinguals retrieved words in English, and bilinguals retrieved words from both languages. Results showed an increased TOT rate in bilinguals. However, bilinguals demonstrated comparable rates of spontaneous resolution, and similar ability to access partial information about target words. Interestingly, bilinguals named the same number of targets as monolinguals when naming an item in either language was counted as a correct response. Besides bilingualism, other factors that predicted TOT rate included word frequency (only for bilinguals), and age (younger participants had more TOTs). Unexpectedly, TOTs for Hebrew targets were not characterized by increased access to grammatical gender and number of syllables relative to control states, thus contrasting notably with TOTs for Italian and English targets respectively. We discuss these results in terms of their relevance for constraining models of bilingual lexical access and models of TOT.

Frequency Drives Lexical Access in Reading but Not in Speaking: The Frequency-Lag Hypothesis

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 constraint effects were larger in production than in reading. Frequency effects were larger in production than in reading without constraining context but larger in reading than in production with constraining context. Bilingual disadvantages were modulated by frequency in production but not in eye fixation times, were not smaller in low-constraint contexts, and were reduced by high-constraint contexts only in production and only at the lowest level of English proficiency. These results challenge existing accounts of bilingual disadvantages and reveal fundamentally different processes during lexical access across modalities, entailing a primarily semantically driven search in production but a frequency-driven search in comprehension. The apparently more interactive process in production than comprehension could simply reflect a greater number of frequency-sensitive processing stages in production.

Lexical access in bilingual speakers: What's the (hard) problem?

difficult to “decide” between the two (the “hard problem”) ‐ yet in some cases bilinguals benefit from the presence of a translation equivalent “competitor”. In this article, we review three models that have been proposed as solutions to the hard problem. Each of these models has difficulty accounting for the full range of findings in the literature but we suggest that these shortcomings stem from their acceptance of the assumption that lexical selection is competitive. We argue that without this assumption each proposal is able to provide a full account of the empirical findings. We conclude by suggesting that the simplest of these proposals should be rejected before more complicated models are considered.

From tip-of-the-tongue (TOT) data to theoretical implications in two steps: when more TOTs means better retrieval.

Two experiments in which participants named pictured objects with difficult or easier names, and a reanalysis and review of published data, reveal that problematic measures used in previous studies obscured the implications of group differences in tip-of-the-tongue (TOT) rates. In Experiment 1, increased age led to more TOTs for difficult but not easy targets. In Experiment 2, bilinguals had more TOTs than monolinguals for easy targets but fewer TOTs for difficult targets. The authors developed a theoretically motivated measure that clarifies the implications of TOT data by linking all responses elicited in the TOT paradigm with either success or failure in completing 2 retrieval steps in current models of language production. The 2-step analysis reveals a common mechanism for the age and bilingualism effects and implies that age has both positive and negative effects on retrieval.

Self-Ratings of Spoken Language Dominance: A Multilingual Naming Test (MINT) and Preliminary Norms for Young and Aging Spanish-English Bilinguals.

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 named pictures in a Multilingual Naming Test (MINT, and in Experiment 1 also the Boston Naming Test; BNT). Self-ratings, proficiency interview, and the MINT did not differ significantly in classifying bilinguals into language-dominance groups, but naming tests (especially the BNT) classified bilinguals as more English-dominant than other measures. Strong correlations were observed between measures of proficiency in each language and language-dominance, but not degree of balanced bilingualism (index scores). Depending on the measure, up to 60% of bilinguals scored best in their self-reported non-dominant language. The BNT distorted bilingual assessment by underestimating ability in Spanish. These results illustrate what self-ratings can and cannot provide, illustrate the pitfalls of testing bilinguals with measures designed for monolinguals, and invite a multi-measure goal driven approach to classifying bilinguals into dominance groups.

What causes the bilingual disadvantage in verbal fluency? : The dual-task analogy

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 were obtained comparing the dominant to the non-dominant languages within bilinguals. Additionally, bilinguals produced significantly lower-frequency words and a greater proportion of cognate responses than monolinguals, and bilinguals produced more cross-language intrusion errors when speaking the non-dominant language, but almost no such intrusions when speaking the dominant language. These results support an analogy between bilingualism and dual-task effects (Rohrer et al., 1995), implying a role for between-language interference in explaining the bilingual fluency disadvantage, and suggest that bilingual fluency will be maximized under testing conditions that minimize such interference. More generally, the findings suggest a role for selection by competition in language production, and that such competition is more influential in relatively unconstrained production tasks.

Cross-Language Intrusion Errors in Aging Bilinguals Reveal the Link Between Executive Control and Language Selection

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-fluency task, in which they produced words in 18 categories (9 in each language), and a flanker task. Performance on both tasks exhibited robust effects of aging, but cross-language and within-language errors on the verbal-fluency task differed in a number of ways. Within-language errors occurred relatively often and decreased with higher levels of education in both younger and older bilinguals. In contrast, cross-language intrusions (e.g., inadvertently saying an English word on a Spanish-language trial) were rarely produced, were not associated with education level, and were strongly associated with flanker-task errors in older but not younger bilinguals. These results imply that executive control plays a role in maintaining language selection, but they also suggest the presence of independent forces that prevent language-selection errors.

Neuropsychological, Cognitive, and Theoretical Considerations for Evaluation of Bilingual Individuals

As the number of bilinguals in the USA grows rapidly, it is increasingly important for neuropsychologists to be equipped and trained to address the unique challenges inherent in conducting ethical and competent neuropsychological evaluations with this population. Research on bilingualism has focused on two key cognitive mechanisms that introduce differences between bilinguals and monolinguals: (a) reduced frequency of language-specific use (weaker links), and (b) competition for selection within the language system in bilinguals (interference). Both mechanisms are needed to explain how bilingualism affects neuropsychological test performance, including the robust bilingual disadvantages found on verbal tasks, and more subtle bilingual advantages on some measures of cognitive control. These empirical results and theoretical claims can be used to derive a theoretically informed method for assessing cognitive status in bilinguals. We present specific considerations for measuring degree of bilingualism for both clients and examiners to aid in determinations of approaches to testing bilinguals, with practical guidelines for incorporating models of bilingualism and recent experimental data into neuropsychological evaluations. This integrated approach promises to provide improved clinical services for bilingual clients, and will also contribute to a program of research that will ultimately reveal the mechanisms underlying language processing and executive functioning in bilinguals and monolinguals alike.

“Tip of the Fingers” Experiences by Deaf Signers Insights Into the Organization of a Sign-Based Lexicon

The “tip of the fingers” phenomenon (TOF) for sign language parallels the “tip of the tongue” phenomenon (TOT) for spoken language. During a TOF, signers are sure they know a sign but cannot retrieve it. Although some theories collapse semantics and phonology in sign language and thus predict that TOFs should not occur, TOFs were elicited in the current study. Like TOTs, TOFs often resolve spontaneously, commonly involve targets that are proper names, and frequently include partial access to phonology. Specifically, signers were more likely to retrieve a target signs handshape, location, and orientation than to retrieve its movement. Signers also frequently recalled the first letter of a finger-spelled word. The existence of TOFs supports two-stage retrieval and a division between semantics and phonology in American Sign Language. The partial phonological information available during TOFs suggests that phonological features are accessed more simultaneously during lexical access for signed language than during lexical access for spoken language.