Limited connectedness of spontaneous speech may be a marker of dementia due to Alzheimer's disease.

The study evaluated the connectedness of spontaneous speech production in individuals with dementia as a potential predictor of dementia severity. Data were derived from the baseline sample of 143 individuals with dementia in the English Pitt corpus. Dementia severity was assessed via the Mini Mental Status Exam, the Mattis Dementia Rating Scale, and the Blessed Dementia Scale. Language abilities were evaluated using verbal fluency and picture description tasks. Graph analysis was carried out for the picture description task using the computational tool SpeechGraphs to calculate connectedness. Results demonstrated that higher educational attainment, higher verbal fluency and strongly-connected spontaneous speech were associated with better cognitive function. Results suggest that automated language processing approaches, such as graph structure analysis, may provide a faster and ecologically valid method of detecting dementia symptoms.

A large-scale database of Chinese characters and words collected from elementary school textbooks.

Lexical databases are essential tools for studies on language processing and acquisition. Most previous Chinese lexical databases have focused on materials for adults, yet little is known about reading materials for children and how lexical properties from these materials affect children's reading comprehension. In the present study, we provided the first large database of 2999 Chinese characters and 2182 words collected from the official textbooks recently issued by the Ministry of Education (MOE) of the People's Republic of China for most elementary schools in Mainland China, as well as norms from both school-aged children and adults. The database incorporates key orthographic, phonological, and semantic factors from these lexical units. A word-naming task was used to investigate the effects of these factors in character and word processing in both adults and children. The results suggest that: (1) as the grade level increases, visual complexity of those characters and words increases whereas semantic richness and frequency decreases; (2) the effects of lexical predictors on processing both characters and words vary across children and adults; (3) the effect of age of acquisition shows different patterns on character and word-naming performance. The database is available on Open Science Framework (OSF) ( https://osf.io/ynk8c/?view_only=5186bd68549340bd923e9b6531d2c820 ) for future studies on Chinese language development.

Visual recognition of identical cognates involves sublexical inhibition and lexical facilitation.

The study investigated the consequences of cross-language activation on the time course of bilingual word recognition. Twenty-two Spanish-English bilinguals and 21 English monolingual controls decided whether visually presented letter strings were English words, while behavioral and event-related potential responses were recorded. The language status of words was manipulated experimentally, such that words were either identical cognates between English and Spanish (e.g. CLUB) or noncognates (e.g. CLOCK). Participants were equally fast in responding to cognate and noncognate words. Bilinguals were more accurate in responding to cognates, whereas monolinguals exhibited higher accuracy in response to noncognates. Critically, bilinguals produced larger P200 followed by smaller N400 responses to cognates than noncognates, whereas monolinguals showed a pattern of reduced N400 responses to cognates. The results of the current study indicate that cross-language activation may not only result in lexical facilitation (indexed by a reduction of the N400 response to cognates) as a result of shared form-meaning associations across languages but also in sublexical inhibition (indexed by a larger P200 response to cognates) as a consequence of cross-language competition among phonological forms. Results support the language-nonselective view of bilingual lexical access and suggest that while lexical facilitation for identical cognates may be observed at most levels of second language proficiency, sublexical inhibition in response to identical cognates may be a marker of advanced levels of proficiency.

Does MOED Rhyme with FRUIT? An event-related potential study of cross-language rhyming.

The study aimed to characterize the event-related potentials signature elicited by visual rhyme judgements across two alphabetic orthographies that differ in depth (shallow: Dutch; deep: English) and by spelling-sound consistency in a deep L2-English orthography. Twenty-four Dutch-English bilinguals who varied on measures of L2-English proficiency, made rhyme judgments of semantically unrelated Dutch-English word pairs presented sequentially in the visual modality, while behavioral and electrophysiological responses were recorded. The spelling-sound consistency of target words was varied systematically. Nonrhyming targets elicited a larger N450 amplitude than rhyming targets, indicating sensitivity to mismatching phonology across languages. English target words with consistent spelling-sound mappings elicited less negative N250 amplitudes when preceded by rhyming Dutch primes. Overall, event-related potentials revealed robust responses to phonological mismatch, but subtle responses to spelling-sound inconsistency in L2-English. Results suggest that bilingual readers of a shallow L1 orthography who are immersed in an L1-speaking environment may not tune into the degree of spelling-sound consistency of a deep L2 orthography.

Graph structure analysis of speech production among second language learners of Spanish and Chinese.

Language experience shapes the gradual maturation of speech production in both native (L1) and second (L2) languages. Structural aspects like the connectedness of spontaneous narratives reveal this maturation progress in L1 acquisition and, as it does not rely on semantics, it could also reveal structural pattern changes during L2 acquisition. The current study tested whether L2 lexical retrieval associated with vocabulary knowledge could impact the global connectedness of narratives during the initial stages of L2 acquisition. Specifically, the study evaluated the relationship between graph structure (long-range recurrence or connectedness) and L2 learners' oral production in the L2 and L1. Seventy-nine college-aged students who were native speakers of English and had received classroom instruction in either L2-Spanish or L2-Chinese participated in this study. Three tasks were used: semantic fluency, phonemic fluency and picture description. Measures were operationalized as the number of words per minute in the case of the semantic and phonemic fluency tasks. Graph analysis was carried out for the picture description task using the computational tool SpeechGraphs to calculate connectedness. Results revealed significant positive correlations between connectedness in the picture description task and measures of speech production (number of correct responses per minute) in the phonemic and semantic fluency tasks. These correlations were only significant for the participants' L2- Spanish and Chinese. Results indicate that producing low connectedness narratives in L2 may be a marker of the initial stages of L2 oral development. These findings are consistent with the pattern reported in the early stages of L1 literacy. Future studies should further explore the interactions between graph structure and second language production proficiency, including more advanced stages of L2 learning and considering the role of cognitive abilities in this process.

Event-related potentials reveal that bilinguals are more efficient in resolving conflict than monolinguals.

In the current study, we evaluated behavioral and electrophysiological evidence to determine whether bilinguals differ from monolinguals in the efficiency of response inhibition. Bilinguals and matched monolingual controls performed the flanker task while behavioral and electrophysiological measures were collected. Participants were slower and less accurate in responding to incongruent trials, but the magnitude of the behavioral effect of congruence was not modulated by participant group. The electrophysiological data revealed a biphasic N200/P300 signature. Incongruent trials elicited a larger N200 response, followed by a larger P300 response than congruent trials. The mean amplitude of the N200 component, a marker of conflict detection, was not modulated by group, suggesting that monolinguals and bilinguals did not differ on the ability to detect conflict. However, the mean amplitude of the P300 component, an index of response inhibition, was smaller in bilinguals than monolinguals. This indicates that bilinguals may be more efficient in resolving response conflict relative to monolinguals. Even though the two groups do not differ in behavioral task performance, the event-related potential (ERP) data suggest that monolinguals may be working harder to reach similar patterns of performance as bilinguals. The P300 magnitude correlated positively with picture naming latencies and negatively with Operation Span scores, suggesting that the ERP response to nonlinguistic conflict resolution may capture individual differences in language proficiency and cognitive resources.

Different inhibitory control components predict different levels of language control in bilinguals.

In recent years, some studies have started to explore the impact of individual general executive functions (EFs) on bilingual language control. To our knowledge, few studies have systematically examined various components of EFs on different levels of language control in bilinguals. In two experiments, we investigated the effects of two components of IC on different levels of bilingual language control. The language-switching task was used to tap into language control at different levels. The Simon task was used to measure interference suppression in Experiment 1, and a go/no-go task was used to measure response inhibition in Experiment 2. Experiment 1 found that the smaller the Simon effect was, the larger the asymmetry of switch costs was. Experiment 2 found that the shorter the go response time was, the larger the global slowing effect was. Taken together, these findings suggest that the interference suppression component of domain-general IC facilitates local level language control, while response inhibition impacts global level language control in bilinguals.

Impaired Lexical Selection and Fluency in Post-Stroke Aphasia.

BACKGROUND: Deficits in fluent language production are a hallmark of aphasia and may arise from impairments at different levels in the language system. It has been proposed that difficulty resolving lexical competition contributes to fluency deficits. AIMS: The present study tested this hypothesis in a novel way: by examining whether narrative speech production fluency is associated with difficulty resolving lexical competition in spoken word recognition as measured by sensitivity to phonological neighborhood density. METHODS & PROCEDURES: Nineteen participants with aphasia and 15 neurologically intact older adults identified spoken words that varied in phonological neighborhood density and were presented in moderate noise. OUTCOMES & RESULTS: Neurologically intact participants exhibited the standard inhibitory effect of phonological neighborhood density on response times: slower recognition of spoken words from denser neighborhoods. Among participants with aphasia, the inhibitory effect of phonological neighborhood density (less accurate recognition of spoken words from denser neighborhoods) was smaller for participants with greater fluency. The neighborhood effect was larger for participants with greater receptive vocabulary knowledge, indicating that the fluency effect was not a result of general lexical deficits. CONCLUSIONS: These results are consistent with the hypothesis that impaired lexical selection is a contributing factor in fluency deficits in post-stroke aphasia.