James Bartolotti

CLEARPOND: Cross-Linguistic Easy-Access Resource for Phonological and Orthographic Neighborhood Densities

Past research has demonstrated cross-linguistic, cross-modal, and task-dependent differences in neighborhood density effects, indicating a need to control for neighborhood variables when developing and interpreting research on language processing. The goals of the present paper are two-fold: (1) to introduce CLEARPOND (Cross-Linguistic Easy-Access Resource for Phonological and Orthographic Neighborhood Densities), a centralized database of phonological and orthographic neighborhood information, both within and between languages, for five commonly-studied languages: Dutch, English, French, German, and Spanish; and (2) to show how CLEARPOND can be used to compare general properties of phonological and orthographic neighborhoods across languages. CLEARPOND allows researchers to input a word or list of words and obtain phonological and orthographic neighbors, neighborhood densities, mean neighborhood frequencies, word lengths by number of phonemes and graphemes, and spoken-word frequencies. Neighbors can be defined by substitution, deletion, and/or addition, and the database can be queried separately along each metric or summed across all three. Neighborhood values can be obtained both within and across languages, and outputs can optionally be restricted to neighbors of higher frequency. To enable researchers to more quickly and easily develop stimuli, CLEARPOND can also be searched by features, generating lists of words that meet precise criteria, such as a specific range of neighborhood sizes, lexical frequencies, and/or word lengths. CLEARPOND is freely-available to researchers and the public as a searchable, online database and for download at http://clearpond.northwestern.edu.

Bilingualism and inhibitory control influence statistical learning of novel word forms.

We examined the influence of bilingual experience and inhibitory control on the ability to learn a novel language. Using a statistical learning paradigm, participants learned words in two novel languages that were based on the International Morse Code. First, participants listened to a continuous stream of words in a Morse code language to test their ability to segment words from continuous speech. Since Morse code does not overlap in form with natural languages, interference from known languages was minimized. Next, participants listened to another Morse code language composed of new words that conflicted with the first Morse code language. Interference in this second language was high due to conflict between languages and due to the presence of two colliding cues (compressed pauses between words and statistical regularities) that competed to define word boundaries. Results suggest that bilingual experience can improve word learning when interference from other languages is low, while inhibitory control ability can improve word learning when interference from other languages is high. We conclude that the ability to extract novel words from continuous speech is a skill that is affected both by linguistic factors, such as bilingual experience, and by cognitive abilities, such as inhibitory control.

Bilingualism and Musicianship Enhance Cognitive Control

Learning how to speak a second language (i.e., becoming a bilingual) and learning how to play a musical instrument (i.e., becoming a musician) are both thought to increase executive control through experience-dependent plasticity. However, evidence supporting this effect is mixed for bilingualism and limited for musicianship. In addition, the combined effects of bilingualism and musicianship on executive control are unknown. To determine whether bilingualism, musicianship, and combined bilingualism and musicianship improve executive control, we tested 219 young adults belonging to one of four groups (bilinguals, musicians, bilingual musicians, and controls) on a nonlinguistic, nonmusical, visual-spatial Simon task that measured the ability to ignore an irrelevant and misinformative cue. Results revealed that bilinguals, musicians, and bilingual musicians showed an enhanced ability to ignore a distracting cue relative to controls, with similar levels of superior performance among bilinguals, musicians, and bilingual musicians. These results indicate that bilingualism and musicianship improve executive control and have implications for educational and rehabilitation programs that use music and foreign language instruction to boost cognitive performance.

Changes in Task-Related Functional Connectivity across Multiple Spatial Scales Are Related to Reading Performance

Reading requires the interaction of a distributed set of cortical areas whose distinct patterns give rise to a wide range of individual skill. However, the nature of these neural interactions and their relation to reading performance are still poorly understood. Functional connectivity analyses of fMRI data can be used to characterize the nature of interactivity of distributed brain networks, yet most previous studies have focused on connectivity during task-free (i.e., “resting state”) conditions. Here, we report new methods for assessing task-related functional connectivity using data-driven graph theoretical methods and describe how large-scale patterns of connectivity relate to individual variability in reading performance among children. We found that connectivity patterns of subjects performing a reading task could be decomposed hierarchically into multiple sub-networks, and we observed stronger long-range interaction between sub-networks in subjects with higher task accuracy. Additionally, we found a network of hub regions known to be critical to reading that displays increased short-range synchronization in higher accuracy subjects. These individual differences in task-related functional connectivity reveal that increased interaction between distant regions, coupled with selective local integration within key regions, is associated with better reading performance. Importantly, we show that task-related neuroimaging data contains far more information than usually extracted via standard univariate analyses – information that can meaningfully relate neural connectivity patterns to cognition and task.

Bilingual Cortical Control of Between- and Within-Language Competition

The human capacity to master multiple languages is remarkable and leads to structural and functional changes in the brain. Understanding how the brain accommodates multiple languages simultaneously is crucial to developing a complete picture of our species’ linguistic capabilities. To examine the neural mechanisms involved in processing two languages, we looked at cortical activation in Spanish-English bilinguals in response to phonological competition either between two languages or within a language. Participants recognized spoken words in a visual world task while their brains were scanned using functional magnetic resonance imaging (fMRI). Results revealed that between-language competition recruited a larger network of frontal control and basal ganglia regions than within-language competition. Bilinguals also recruited more neural resources to manage between-language competition from the dominant language compared to competition from the less dominant language. Additionally, bilinguals’ activation of the basal ganglia was inversely correlated with their executive function ability, suggesting that bilinguals compensated for lower levels of cognitive control by recruiting a broader neural network to manage more difficult tasks. These results provide evidence for differences in neural responses to linguistic competition between versus within languages, and demonstrate the brain’s remarkable plasticity, where language experience can change neural processing.

Neural signatures of second language learning and control

&NA; Experience with multiple languages has unique effects on cortical structure and information processing. Differences in gray matter density and patterns of cortical activation are observed in lifelong bilinguals compared to monolinguals as a result of their experience managing interference across languages. Monolinguals who acquire a second language later in life begin to encounter the same type of linguistic interference as bilinguals, but with a different pre‐existing language architecture. The current study used functional magnetic resonance imaging to explore the beginning stages of second language acquisition and cross‐linguistic interference in monolingual adults. We found that after English monolinguals learned novel Spanish vocabulary, English and Spanish auditory words led to distinct patterns of cortical activation, with greater recruitment of posterior parietal regions in response to English words and of left hippocampus in response to Spanish words. In addition, cross‐linguistic interference from English influenced processing of newly‐learned Spanish words, decreasing hippocampus activity. Results suggest that monolinguals may rely on different memory systems to process a newly‐learned second language, and that the second language system is sensitive to native language interference. HighlightsPhonological memory and inhibitory control affect second language vocabulary learning.Distinct neural activation for native versus newly‐learned second language words.Cross‐linguistic interference alters hippocampus activation in the second language.

Orthographic knowledge and lexical form influence vocabulary learning

Many adults struggle with second language acquisition, but learn new native-language words relatively easily. We investigated the role of sublexical native-language patterns on novel word acquisition. Twenty English monolinguals learned 48 novel written words in five repeated testing blocks. Half were orthographically wordlike (e.g., nish, high neighborhood density and high segment/bigram frequency), while half were not (e.g., gofp, low neighborhood density and low segment/bigram frequency). Participants were faster and more accurate at recognizing and producing wordlike items, indicating a native-language similarity benefit. Individual differences in memory and vocabulary size influenced learning, and error analyses indicated that participants extracted probabilistic information from the novel vocabulary. Results suggest that language learners benefit from both native-language overlap and regularities within the novel language.

Learning and processing of orthography-to-phonology mappings in a third language

ABSTRACT Bilinguals’ two languages are both active in parallel, and controlling co-activation is one of bilinguals’ principle challenges. Trilingualism multiplies this challenge. To investigate how third language (L3) learners manage interference between languages, Spanish-English bilinguals were taught an artificial language that conflicted with English and Spanish letter-sound mappings. Interference from existing languages was higher for L3 words that were similar to L1 or L2 words, but this interference decreased over time. After mastering the L3, learners continued to experience competition from their other languages. Notably, spoken L3 words activated orthography in all three languages, causing participants to experience cross-linguistic orthographic competition in the absence of phonological overlap. Results indicate that L3 learners are able to control between-language interference from the L1 and L2. We conclude that while the transition from two languages to three presents additional challenges, bilinguals are able to successfully manage competition between languages in this new context.