Selecting the Most Important Features for Predicting Mild Cognitive Impairment from Thai Verbal Fluency Assessments.

Mild cognitive impairment (MCI) is an early stage of cognitive decline or memory loss, commonly found among the elderly. A phonemic verbal fluency (PVF) task is a standard cognitive test that participants are asked to produce words starting with given letters, such as "F" in English and "ก" /k/ in Thai. With state-of-the-art machine learning techniques, features extracted from the PVF data have been widely used to detect MCI. The PVF features, including acoustic features, semantic features, and word grouping, have been studied in many languages but not Thai. However, applying the same PVF feature extraction methods used in English to Thai yields unpleasant results due to different language characteristics. This study performs analytical feature extraction on Thai PVF data to classify MCI patients. In particular, we propose novel approaches to extract features based on phonemic clustering (ability to cluster words by phonemes) and switching (ability to shift between clusters) for the Thai PVF data. The comparison results of the three classifiers revealed that the support vector machine performed the best with an area under the receiver operating characteristic curve (AUC) of 0.733 (N = 100). Furthermore, our implemented guidelines extracted efficient features, which support the machine learning models regarding MCI detection on Thai PVF data.

Symmetry of the arcuate fasciculus and its impact on language performance of patients with brain tumors in the language-dominant hemisphere.

OBJECTIVE Cerebral damage in frontal, parietal, and temporal brain areas and, probably more importantly, their interconnections can lead to deficits in language. However, neural plasticity and repair allow the brain to partly compensate for neural injury, mediated by both functional and structural changes. In this study, the authors sought to systematically investigate the relationship between language performance in brain tumor patients and structural perisylvian pathways (i.e., the arcuate fasciculus [AF]) using probabilistic fiber tracking on diffusion tensor imaging. The authors used a previously proposed model in which the AF is divided into anterior, long, and posterior segments. The authors hypothesized that right-handed patients with gliomas in the language-dominant (left) hemisphere would benefit from a more symmetrical or right-lateralized language pathway in terms of better preservation of language abilities. Furthermore, they investigated to what extent specific tumor characteristics, including proximity to the AF, affect language outcome in such patients. METHODS Twenty-seven right-handed patients (12 males and 15 females; mean age 52 ± 16 years) with 11 low-grade and 16 high-grade gliomas of the left hemisphere underwent 3-T diffusion-weighted MRI (30 directions) and language assessment as part of presurgical planning. For a systematic quantitative evaluation of the AF, probabilistic fiber tracking with a 2 regions of interest approach was carried out. Volumes of the 3 segments of both hemispheric AFs were evaluated by quantifying normalized and thresholded pathways. Resulting values served to generate the laterality index of the AFs. RESULTS Patients without language deficits tended to have an AF that was symmetric or lateralized to the right, whereas patients with deficits in language significantly more often demonstrated a left-lateralized posterior segment of the AF. Patients with high-grade gliomas had more severe language deficits than those with low-grade gliomas. Backward logistic regression revealed the laterality index of the posterior AF segment and tumor grade as the only independent statistically significant predictors for language deficits in this cohort. CONCLUSIONS In addition to the well-known fact that tumor entity influences behavioral outcome, the authors' findings suggest that the right homologs of structural language-associated pathways could be supportive for language function and facilitate compensation mechanisms after brain damage in functionally eloquent areas. This further indicates that knowledge about preoperative functional redistribution (identified by neurofunctional imaging) increases the chance for total or near-total resections of tumors in eloquent areas. In the future, longitudinal studies with larger groups are mandatory to overcome the methodological limitations of this cross-sectional study and to map neuroplastic changes associated with language performance and rehabilitation in brain tumor patients.

Methodological Criteria for Scoring Clustering and Switching in Verbal Fluency Tasks / Critérios Metodológicos para Análises de Clustering e Switching em tarefas de Fluência Verbal / Criterios Metodológicos para Análisis de Estrategias de Agrupación en Tareas de Fluidez Verbal

The objective of this study was to describe an adaptation to Brazilian Portuguese of the methodological criteria for analysis of clustering and switching in semantic verbal fluency (SVF) and phonemic verbal fluency (PVF) tasks. The adaptation process consisted of six steps, including the selection of the clustering and switching variables based on data from a sample of 419 children and the analysis of inter-rater reliability (six raters). The following variables were scored: the total number of words generated the raw number of clusters, the mean cluster size, and the raw number of switches. There was a significant association between raters (intra-class correlation coefficients between 0.95 and 0.99), showing that the analytical method was reliable. Our study provides an evaluation of SVF and PVF tasks that goes beyond the overall score, making it possible to investigate the cognitive processes underlying this neuropsychological function.

Este artigo objetiva apresentar uma adaptação ao português brasileiro dos critérios metodológicos para análises de clustering e switching em tarefas de fluência verbal semântica (FVS) e ortográfica (FVO). São descritas as seis etapas realizadas no processo de adaptação destes critérios, incluindo o processo de extração das variáveis de clustering e switching a partir de dados de amostras de crianças (N=419) e a análise da fidedignidade da concordância entre juízes (N=6). As variáveis avaliadas são número total de palavras evocadas, número de clusters, média do tamanho dos clusters e número de switches. Houve forte associação entre juízes (Coeficientes de Correlação Intraclasse entre 0,95 a 0,99) indicando fidedignidade do método de análise. Este estudo contribui com a avaliação da FVS e FVO para além do escore geral, permitindo investigar os processos cognitivos subjacentes a esta função neuropsicológica.

Este artículo presenta una adaptación para el portugués brasileño de criterios metodológicos de análisis de estrategias de agrupación (clustering y switching) en tareas de fluidez verbal semántica (FVS) y fluidez verbal fonológica (FVF). El proceso de adaptación de estos criterios consiste en seis pasos, incluyendo el proceso de extracción de las variables de clustering y switching de una muestra formada por 419 niños y el análisis de fiabilidad entre seis jueces. Se investigaron las siguientes variables: número total de palabras generadas, número de grupos de palabras (clusters), tamaño medio de los grupos y número de saltos (switches). Hubo una fuerte asociación entre jueces (coeficientes de correlación intraclase entre 0,95 y 0,99), indicando así la fiabilidad del método analítico. Este estudio contribuye a la evaluación de la FVS y FVF más allá de la puntuación global, lo que permite investigar los procesos cognitivos subyacentes a esta función neuropsicológica.

Methodological criteria for scoring clustering and switching in verbal fluency tasks / Critérios metodológicos para análises de clustering e switching em tarefas de fluência verbal / Criterios metodológicos para análisis de estrategias de agrupación en tareas de fluidez verbal

The objective of this study was to describe an adaptation to Brazilian Portuguese of the methodological criteria for analysis of clustering and switching in semantic verbal fluency (SVF) and phonemic verbal fluency (PVF) tasks. The adaptation process consisted of six steps, including the selection of the clustering and switching variables based on data from a sample of 419 children and the analysis of inter-rater reliability (six raters). The following variables were scored: the total number of words generated the raw number of clusters, the mean cluster size, and the raw number of switches. There was a significant association between raters (intra-class correlation coefficients between 0.95 and 0.99), showing that the analytical method was reliable. Our study provides an evaluation of SVF and PVF tasks that goes beyond the overall score, making it possible to investigate the cognitive processes underlying this neuropsychological function.

Este artigo objetiva apresentar uma adaptação ao português brasileiro dos critérios metodológicos para análises de clustering e switching em tarefas de fluência verbal semântica (FVS) e ortográfica (FVO). São descritas as seis etapas realizadas no processo de adaptação destes critérios, incluindo o processo de extração das variáveis de clustering e switching a partir de dados de amostras de crianças (N=419) e a análise da fidedignidade da concordância entre juízes (N=6). As variáveis avaliadas são número total de palavras evocadas, número de clusters, média do tamanho dos clusters e número de switches. Houve forte associação entre juízes (Coeficientes de Correlação Intraclasse entre 0,95 a 0,99) indicando fidedignidade do método de análise. Este estudo contribui com a avaliação da FVS e FVO para além do escore geral, permitindo investigar os processos cognitivos subjacentes a esta função neuropsicológica.

Este artículo presenta una adaptación para el portugués brasileño de criterios metodológicos de análisis de estrategias de agrupación (clustering y switching) en tareas de fluidez verbal semántica (FVS) y fluidez verbal fonológica (FVF). El proceso de adaptación de estos criterios consiste en seis pasos, incluyendo el proceso de extracción de las variables de clustering y switching de una muestra formada por 419 niños y el análisis de fiabilidad entre seis jueces. Se investigaron las siguientes variables: número total de palabras generadas, número de grupos de palabras (clusters), tamaño medio de los grupos y número de saltos (switches). Hubo una fuerte asociación entre jueces (coeficientes de correlación intraclase entre 0,95 y 0,99), indicando así la fiabilidad del método analítico. Este estudio contribuye a la evaluación de la FVS y FVF más allá de la puntuación global, lo que permite investigar los procesos cognitivos subyacentes a esta función neuropsicológica.

Fluência verbal semântica e fonêmica em crianças: funções cognitivas e análise temporal / Semantic and phonemic verbal fl uency in children: cognitive functions and temporal analysis

Testes de fluência verbal são medidas sensíveis a diferentes funções neuropsicológicas usadas na avaliação da integridade dos lobos frontal e temporal. Participaram neste estudo 120 crianças (7 a 10 anos) que foram avaliadas por meio da prova de fluência verbal semântica e fonêmica. Os resultados obtidos das análises fatoriais exploratória e confirmatória e da análise de correlação parecem indicar que essas duas provas dependem de diferentes funções neurocognitivas. O número de palavras produzidas nas tarefas fonêmicas foi significativamente inferior ao obtido nas tarefas semânticas, uma vez que as primeiras são cognitivamente mais complexas. Não foram observadas diferenças de gênero, mas foi observado um efeito significativo em função da idade da criança, o que corrobora a sensibilidade desses testes aos processos neurodesenvolvimentais. Na análise do desempenho ao longo dos 60 segundos, observa-se uma maior produção de palavras nos primeiros 15 segundos e uma significativa diminuição ao longo dos restantes 45 segundos.(AU)

Verbal fluency tests are sensitive to different neuropsychological functions used in assessing the integrity of the frontal and temporal lobes. In this study, 120 healthy children (aged 7 to 10 years) were examined through a semantic and a phonemic verbal fluency test. The results of exploratory factor analysis, confirmatory factor analysis and correlation analysis seem to indicate that these two verbal fluency tests depend on different neurocognitive functions. The number of words produced in the phonemic task was significantly lower than the semantic task, indicating that is cognitively more complex. No gender differences were found, but a significant effect was observed for children’s age, showing the sensitivity of these verbal fluency tests to neurodevelopmental processes. The analyze of performance over the 60 seconds showed a significant production of words in the first 15 seconds and decrease over the remaining 45 seconds.(AU)

Las pruebas de fluidez verbal son medidas sensibles a las diferentes funciones neuropsicológicas utilizadas en la evaluación de la integridad de los lobos frontal y temporal. Participaron de este estudio 120 niños (7 a 10 años) que fueron evaluados mediante la prueba de fluidez verbal semántica y fonémica. Los resultados obtenidos de los análisis factoriales exploratorio y confirmatorio y del análisis de correlación indicaron que esas dos pruebas dependen de diferentes funciones neurocognitivas. El número de palabras producidas en las tareas fonémicas fue significativamente inferior al obtenido en las tareas semánticas, ya que las primeras son cognitivamente más complejas. No hubo diferencias entre los sexos, pero fue observado un efecto significativo en función de la edad de niños, lo que corrobora la sensibilidad de esos testes a los procesos neurológicos del desarrollo. En el análisis del desempeño a lo largo de los 60 segundos, se observa una mayor producción de palabras en los primeros 15 segundos y una significativa disminución a lo largo de los restantes 45 segundos.(AU)

Fluência verbal semântica e fonêmica em crianças: funções cognitivas e análise temporal / Semantic and phonemic verbal fl uency in children: cognitive functions and temporal analysis / Fluidez verbal semántica y fonémica en niños: funciones cognitivas y análisis temporal

Testes de fluência verbal são medidas sensíveis a diferentes funções neuropsicológicas usadas na avaliação da integridade dos lobos frontal e temporal. Participaram neste estudo 120 crianças (7 a 10 anos) que foram avaliadas por meio da prova de fluência verbal semântica e fonêmica. Os resultados obtidos das análises fatoriais exploratória e confirmatória e da análise de correlação parecem indicar que essas duas provas dependem de diferentes funções neurocognitivas. O número de palavras produzidas nas tarefas fonêmicas foi significativamente inferior ao obtido nas tarefas semânticas, uma vez que as primeiras são cognitivamente mais complexas. Não foram observadas diferenças de gênero, mas foi observado um efeito significativo em função da idade da criança, o que corrobora a sensibilidade desses testes aos processos neurodesenvolvimentais. Na análise do desempenho ao longo dos 60 segundos, observa-se uma maior produção de palavras nos primeiros 15 segundos e uma significativa diminuição ao longo dos restantes 45 segundos.

Verbal fluency tests are sensitive to different neuropsychological functions used in assessing the integrity of the frontal and temporal lobes. In this study, 120 healthy children (aged 7 to 10 years) were examined through a semantic and a phonemic verbal fluency test. The results of exploratory factor analysis, confirmatory factor analysis and correlation analysis seem to indicate that these two verbal fluency tests depend on different neurocognitive functions. The number of words produced in the phonemic task was significantly lower than the semantic task, indicating that is cognitively more complex. No gender differences were found, but a significant effect was observed for children’s age, showing the sensitivity of these verbal fluency tests to neurodevelopmental processes. The analyze of performance over the 60 seconds showed a significant production of words in the first 15 seconds and decrease over the remaining 45 seconds.

Las pruebas de fluidez verbal son medidas sensibles a las diferentes funciones neuropsicológicas utilizadas en la evaluación de la integridad de los lobos frontal y temporal. Participaron de este estudio 120 niños (7 a 10 años) que fueron evaluados mediante la prueba de fluidez verbal semántica y fonémica. Los resultados obtenidos de los análisis factoriales exploratorio y confirmatorio y del análisis de correlación indicaron que esas dos pruebas dependen de diferentes funciones neurocognitivas. El número de palabras producidas en las tareas fonémicas fue significativamente inferior al obtenido en las tareas semánticas, ya que las primeras son cognitivamente más complejas. No hubo diferencias entre los sexos, pero fue observado un efecto significativo en función de la edad de niños, lo que corrobora la sensibilidad de esos testes a los procesos neurológicos del desarrollo. En el análisis del desempeño a lo largo de los 60 segundos, se observa una mayor producción de palabras en los primeros 15 segundos y una significativa disminución a lo largo de los restantes 45 segundos.