L1 lexical attrition is the decline of L1 lexical-semantic abilities due to reduced L1 exposure and/or L2 interference. Semantic fluency tasks are central in this research, but traditional analyses are often inconclusive.

To address this, we employed an innovative network science approach to investigate the bilingual lexicon's structural properties. Semantic fluency data were collected from immersed/non-immersed late bilinguals with comparable L2 proficiencies.

Our results indicate that L2 immersion led to more integrated and efficient L2 networks. Crucially, immersion also resulted in L1 attrition (only evident in the network analysis). Immersed participants exhibited less densely connected and sparser L1 networks. Furthermore, network measures suggest that L1 lexical attrition occurs gradually, initially impacting network interconnectivity, while information flow and community structure remain more stable.

Drawing from these insights, we introduce the Lexical Attrition Foundation (LeAF) framework, offering a network-based perspective on lexical attrition development and laying the groundwork for future research.

Research has shown that bilinguals can perform similarly, better or poorly on verbal fluency task compared to monolinguals. Verbal fluency data for semantic (animals, fruits and vegetables, and clothing) and letter fluency (F, A, S) were collected from 25 Bengali–English bilinguals and 25 English monolinguals in English. The groups were matched for receptive vocabulary, age, education and non-verbal intelligence. We used a wide range of measures to characterize fluency performance: number of correct, fluency difference score, time-course analysis (1st RT, Sub-RT, initiation, slope), clustering, and switching. Participants completed three executive control measures tapping into inhibitory control, mental-set shifting and working memory. Differences between the groups were significant when executive control demands were higher such as number of correct responses in letter fluency, fluency difference score, Sub-RT, slope and cluster size for letter fluency, such that bilinguals outperform the monolinguals. Stroop performance correlated positively with the slope only for the bilinguals.

The present research examined whether conceptual divergence is reduced in bilinguals with extensive informal translation experience. Across two experiments, Spanish–English bilinguals (brokers vs. non-brokers) generated exemplars for 10 categories, using the same or different language across sessions. Both groups demonstrated more divergence for different than same language responses across sessions a week apart. More convergence was found in both groups for no delay compared to delayed responses. Brokers showed significantly more convergence in exemplars than non-brokers; for both immediate and delayed sessions Findings indicate exemplars are differentially accessible depending on language and timing of response, but also individual differences in brokering experience. Extensive brokering experience may lead to a more integrated conceptual representation for features of concepts shared across languages. Findings support concept models that emphasize the dynamic and distributed nature of concepts, and underscore the need to consider the cognitive impact of systematic sources of variability among bilinguals.

In 2006, the National Institute of Neurological Disorders and Stroke-Canadian Stroke Network (NINDS-CSN) Vascular Cognitive Impairment Harmonization Standards recommended a 5-Minute Protocol as a brief screening instrument for vascular cognitive impairment (VCI). We report demographically adjusted norms for the 5-Minute Protocol and its relation to other measures of cognitive function and cerebrovascular risk factors. We performed a cross-sectional analysis of 7199 stroke-free adults in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study on the NINDS-CSN 5-Minute Protocol score. Total scores on the 5-Minute Protocol were inversely correlated with age and positively correlated with years of education, and performance on the Six-Item Screener, Word List Learning, and Animal Fluency (all p-values <.001). Higher cerebrovascular risk on the Framingham Stroke Risk Profile (FSRP) was associated with lower total 5-Minute Protocol scores (p <.001). The 5-Minute Protocol also differentiated between participants with and without confirmed stroke and with and without stroke symptom histories (p <.001). The NINDS-CSN 5-Minute Protocol is a brief, easily administered screening measure that is sensitive to cerebrovascular risk and offers a valid method of screening for cognitive impairment in populations at risk for VCI. (JINS, 2014, 20, 1–12)

Patterns of verbal fluency deficits have been explored across different neurodegenerative disorders. This study sought to investigate the specific pattern of verbal fluency performance in cerebral small vessel disease (SVD), which is the most common cause of vascular cognitive impairment, and compare this with Alzheimer's disease (AD). Participants with SVD (n = 45), AD (n = 24) and healthy controls (n = 80) completed assessments of semantic and phonemic fluency. Mixed-model analyses of covariance were used to compare performance on the different fluency tasks between the groups, and a discriminant function analysis was conducted to examine group differentiation. The SVD group was impaired in both fluency tasks when compared to the controls. In contrast, the AD group displayed impairment in semantic fluency only. Discriminant function analysis revealed that fluency scores correctly classified 80% of SVD patients and 92% of AD patients. The pattern of performance observed in the SVD group may reflect deficits in executive function and processing speed impacting equivalently on semantic and phonemic fluency. The differences between the SVD and AD groups highlighted in this study may be useful for distinguishing between these conditions. (JINS, 2014, 20, 1–9)

Functional magnetic resonance imaging (fMRI) studies have identified consistent age-related changes during various cognitive tasks, such that older individuals display more positive and less negative task-related activity than young adults. Recently, evidence shows that chronic physical exercise may alter aging-related changes in brain activity; however, the effect of exercise has not been studied for the neural substrates of language function. Additionally, the potential mechanisms by which aging alters neural recruitment remain understudied. To address these points, the present study enrolled elderly adults who were either sedentary or physically active to characterize the neural correlates of language function during semantic fluency between these groups in comparison to a young adult sample. Participants underwent fMRI during semantic fluency and transcranial magnetic stimulation to collect the ipsilateral silent period, a measure of interhemispheric inhibition. Results indicated that sedentary older adults displayed reductions in negative task-related activity compared to the active old group in areas of the attention network. Longer interhemispheric inhibition was associated with more negative task-related activity in the right and left posterior perisylvian cortex, suggesting that sedentary aging may result in losses in task facilitatory cortical inhibition. However, these losses may be mitigated by regular engagement in physical exercise. (JINS, 2013, 19, 1–10)

Although dialyzed patients often have cognitive problems, little is known about the nature of these deficits. We hypothesized that, in contrast to semantic fluency relying mainly on temporal lobes, phonemic fluency, preferentially depending on functions of frontal-subcortical systems, would be particularly sensitive to the constellation of physiological pathological processes associated with end-stage renal disease and dialysis. Therefore, we longitudinally compared phonemic and semantic fluency performance between 49 dialyzed patients and 30 controls. Overall, patients performed below controls only on the phonemic fluency task. Furthermore, their performance on this task declined over time, whereas there was no change in semantic fluency. Moreover, this decline was related to the presence of hypertension and higher blood urea nitrogen. We suggest that these findings may be due to a combination of vascular and topic effects that impact more on fronto-subcortical than temporal lobe networks, but this speculation requires direct confirmation. (JINS, 2012, 18, 162–167)

Two hundred-thirteen children in grades 1 through 8 were asked to rapidly generate as many names of animals as they could in 60 seconds. These children were age appropriate for their grade level in school, did not receive any form of special education services, and as a group showed (estimated) average intellectual ability. They were primarily from minority (particularly Hispanic) backgrounds and came from families with low socioeconomic status. Normative data are presented. Hierarchical multiple regression analysis revealed that the age range/grade level score accounted for 21.5% of the variability in fluency scores and the Vocabulary level of the child accounted for an additional 5.7%. Level of performance on this animal fluency task was not lower than what has been reported in primarily white children from middle socioeconomic backgrounds. (JINS, 2008, 14, 143–147.)

Sex differences in executive speech tasks, favoring women, have been noted in behavioral studies and functional imaging studies. In the present study, the clustering and switching components of semantic and phonemic verbal fluency tests were examined in 40 healthy men and 40 healthy women. Possible sex differences in the influence of cognitive factors such as speed of information processing, word knowledge, and/or verbal long-term memory on these verbal fluency factors were also assessed. The results showed that women switched more often between categories in the phonemic fluency test, whereas men showed a trend toward a larger cluster size leading to a smaller total number of words generated. Additionally, higher performance on the Digit Symbol test was associated with better performance on the semantic and phonemic verbal fluency test in men, whereas in women, better memory performance was associated with better performance on these verbal fluency tests. Our data indicate that men and women are using different processing strategies for phonemic verbal fluency tests to optimize verbal fluency task performance. In the current study, women adopted a more successful strategy of balancing clustering and switching in the phonemic fluency task. (JINS, 2006, 12, 502–509.)

Previous research has indicated that performance on verbal fluency tests (VFTs) is influenced by language and/or culture. Consequently, normative VFT data for English-speaking people cannot be used for people for whom English is not their first language. The aim of the present study was to provide normative data for the Animal Naming, Profession Naming, and Letter M Naming (four-letter words beginning with the letter M) VFTs for Dutch-speaking populations, based on a large sample (N = 1856) of healthy men and women aged 24–81 years of different educational levels. The results showed that age affected the performance of all VFTs profoundly, but the age effect was not uniform: in the Profession and Letter M Naming VFTs, performance was stable in young adulthood but declined strongly after age 50. In contrast, in the Animal Naming VFT, performance appeared to decline linearly, starting early in life. Furthermore, males had higher scores than females on the Profession Naming VFT, and higher educated participants outperformed their lower educated counterparts on all three VFTs. Regression-based normative data were prepared for the 3 VFTs, and the advantages of using a regression-based normative approach instead of a traditional normative approach are discussed. (JINS, 2006, 12, 80–89.)

We assessed 300 healthy adults in Greece on measures of semantic and phonemic verbal fluency in order to develop norms for the Greek population. We also evaluated the strategies that the participants used spontaneously in order to maximize word production, namely clustering and switching techniques. Our tasks comprised three semantic and three phonemic categories. Consistent with previous investigations of English-speaking samples, we found a contribution of demographic variables to word fluency. Specifically, level of education contributed to total word production, number of switches, and number of repetitive responses on both semantic and phonemic tasks, and the average cluster size only on the phonemic task. Age contributed to total word production and cluster size on the semantic task, and to number of switches on both semantic and phonemic tasks. Sex contributed only to total word production on the semantic task. In our sample, clustering and switching strategies were related to total word production on both tasks, suggesting that these strategies were used effectively. We present tables of normative data stratified by age and level of education. We have also included detailed guidelines for scoring clusters relevant to the Greek population. (JINS, 2004, 10, 164–172.)