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1.
Sci Rep ; 10(1): 20721, 2020 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-33244155

RESUMO

Some of the anatomical and functional basis of cognitive impairment in multiple sclerosis (MS) currently remains unknown. In particular, there is scarce knowledge about modulations in induced EEG (nonphase activity) for diverse frequency bands related to attentional deficits in this pathology. The present study analyzes phase and nonphase alpha and gamma modulations in 26 remitting-relapsing multiple sclerosis patients during their participation in the attention network test compared with twenty-six healthy controls (HCs) matched in sociodemographic variables. Behavioral results showed that the MS group exhibited general slowing, suggesting impairment in alerting and orienting networks, as has been previously described in other studies. Time-frequency analysis of EEG revealed that the gamma band was related to the spatial translation of the attentional focus, and the alpha band seemed to be related to the expectancy mechanisms and cognitive processing of the target. Moreover, phase and nonphase modulations differed in their psychophysiological roles and were affected differently in the MS and HC groups. In summary, nonphase modulations can unveil hidden cognitive mechanisms for phase analysis and complete our knowledge of the neural basis of cognitive impairment in multiple sclerosis pathology.


Assuntos
Atenção/fisiologia , Esclerose Múltipla Recidivante-Remitente/fisiopatologia , Esclerose Múltipla/fisiopatologia , Adulto , Eletroencefalografia/métodos , Feminino , Humanos , Manutenção/métodos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Orientação/fisiologia , Tempo de Reação/fisiologia
2.
Rev Neurol ; 69(10): 423-432, 2019 Nov 16.
Artigo em Espanhol | MEDLINE | ID: mdl-31713229

RESUMO

INTRODUCTION: The Attention Network Test (ANT) has been applied to the study of potential attentional impairments in diverse neuropathologies in the last years. This test allows analyzing of different networks involved in attentional processing (alerting, orientation and executive system). DEVELOPMENT: A specific application of ANT in ADHD patients shows that it is possible to find diverse impairments in the three attentional networks and even some studies revealed no alterations. Potential causes of this heterogeneity in the results could be based in methodological variations between studies, other pathological conditions in the participants and the network effects calculation that has been probed that could be wrongly interpreted. CONCLUSIONS: Despite the lack of conclusive results, this test shows multiple applications that would allow disentangling diverse cognitive impairments in ADHD patients. ANT could analyze diverse cognitive mechanisms that could be compromised in these patients (tonic and phasic alerting, temporal and spatial expectancy, degree of interference of the distractor stimuli, attentional blinking o inhibition of return). This test could help to perform a better characterization of ADHD patients further than the classical forms considered nowadays (unattended and combined).


TITLE: El Attention Network Test en el estudio de los déficits cognitivos de pacientes con trastorno por déficit de atención.Introducción. El Attention Network Test (ANT) se ha aplicado en el estudio de las posibles alteraciones atencionales en diversas neuropatologías en los últimos años. Este test permite el análisis de diversas redes implicadas en el proceso atencional (alerta, orientación y sistema ejecutivo). Desarrollo. La aplicación particular del ANT en pacientes con trastorno por déficit de atención muestra que es posible encontrar diversas alteraciones de las tres redes atencionales según los estudios e incluso, en algunos casos, la ausencia de alteraciones en ellas. Las posibles causas de esta heterogeneidad pueden deberse a variaciones metodológicas en la aplicación del test, otras condiciones patológicas no consideradas de los pacientes y el análisis de redes sugerido por los creadores del modelo y que se ha demostrado en diversos estudios que puede llevar a interpretaciones erróneas. Conclusiones. A pesar de los resultados todavía poco concluyentes con la aplicación del ANT en el trastorno por déficit de atención, este test muestra múltiples aplicaciones que permitirán desentrañar los diversos déficits cognitivos que están presentes en los pacientes con trastorno por déficit de atención. Entre ellos, el test puede analizar diversos mecanismos que pueden estar afectados en estos pacientes (la alerta tónica y fásica, la expectativa temporal o espacial, el grado de interferencia de los estímulos distractores, el parpadeo atencional o la inhibición de retorno). El ANT puede ayudar a una mejor caracterización de los pacientes con trastorno por déficit de atención más allá de las formas clásicas consideradas hasta ahora (inatento o combinado).


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Atenção , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/psicologia , Testes Neuropsicológicos , Adulto , Transtorno do Deficit de Atenção com Hiperatividade/complicações , Criança , Disfunção Cognitiva/complicações , Humanos
3.
Neurosci Biobehav Rev ; 94: 126-148, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30189226

RESUMO

BACKGROUND: Cognitive-motor interference (CMI) has been proposed as a valid marker of daily life impairment in Multiple Sclerosis (MS). The heterogeneity and scarce number of studies regarding CMI in MS has hampered the synthesis of the existing evidence. The present systematic review employed a mixed methods approach with the aim of identifying and describing variables under which CMI is particularly useful to assess patients with MS. RESULTS: MS patients showed significant CMI. The motor variables that were most sensitive in detecting significant CMI were velocity (m/s), cadence (steps/min), and double support (% gait cycle), which was also specific for MS. Among the cognitive tasks, Alternate Alphabet and Serial Subtracting 7 s were sensitive, whereas Verbal Fluency were both sensitive and specific to CMI in MS. CONCLUSIONS: CMI should be assessed in MS with a standardised dual task such as the Verbal Fluency task while walking, with measurements of the double support time and the effect on the cognitive task. The clinical usefulness of CMI in the assessment of patients with MS is discussed.


Assuntos
Cognição , Marcha , Esclerose Múltipla/fisiopatologia , Esclerose Múltipla/psicologia , Desempenho Psicomotor , Humanos
4.
NeuroRehabilitation ; 41(3): 661-671, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29036848

RESUMO

OBJECTIVE: To generate normative data for the Concentration Endurance Test (d2) in Spanish-speaking pediatric populations. METHOD: The sample consisted of 4,373 healthy children from nine countries in Latin America (Chile, Cuba, Ecuador, Guatemala, Honduras, Mexico, Paraguay, Peru, and Puerto Rico) and Spain. Each participant was administered the d2 test as part of a larger neuropsychological battery. The Total number of items processed (TN), Total number of correct responses (CR), Total performance (TP), and Concentration performance (CP) scores were normed using multiple linear regressions and standard deviations of residual values. Age, age2, sex, and mean level of parental education (MLPE) were included as predictors in the analyses. RESULTS: The final multiple linear regression models showed main effects for age on all scores, such that scores increased linearly as a function of age. TN scores were affected by age2 for Guatemala and Puerto Rico; CR scores were affected by age2 for Mexico; TP scores were affected by age2 for Chile, Mexico, Puerto Rico, and Spain; and CP scores for Mexico and Spain. Models indicated that children whose parents had a MLPE >12 years obtained higher scores compared to children whose parents had a MLPE≤12 years for Mexico and Spain in all scores, and Puerto Rico for TN, CR, and TP, and Guatemala and Paraguay for CP scores. Sex affect the scores for Ecuador and Honduras (CP scores). CONCLUSIONS: This is the largest Spanish-speaking pediatric normative study in the world, and it will allow neuropsychologists from these countries to have a more accurate approach to interpret the d2 test in pediatric populations.


Assuntos
Testes Psicológicos/normas , Atenção , Criança , Humanos , Idioma , América Latina , Modelos Lineares , Valores de Referência
5.
NeuroRehabilitation ; 41(3): 639-647, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28946593

RESUMO

OBJECTIVE: To generate normative data for the Symbol Digit Modalities Test (SDMT) in Spanish-speaking pediatric populations. METHOD: The sample consisted of 4,373 healthy children from nine countries in Latin America (Chile, Cuba, Ecuador, Guatemala, Honduras, Mexico, Paraguay, Peru, and Puerto Rico) and Spain. Each participant was administered the SDMT as part of a larger neuropsychological battery. SDMT scores were normed using multiple linear regressions and standard deviations of residual values. Age, age2, sex, and mean level of parental education (MLPE) were included as predictors in the analyses. RESULTS: The final multiple linear regression models showed main effects for age in all countries, such that score increased linearly as a function of age. In addition, age2 had a significant effect in all countries, except in Honduras and Puerto Rico. Models indicated that children whose parent(s) had a MLPE >12 years of education obtained higher score compared to children whose parent(s) had a MLPE ≤12 years for Chile, Guatemala, Mexico, and Spain. Sex affected SDMT score for Paraguay and Spain. CONCLUSIONS: This is the largest Spanish-speaking pediatric normative study in the world, and it will allow neuropsychologists from these countries to have a more accurate interpretation of the SDMT with pediatric populations.


Assuntos
Testes Neuropsicológicos/normas , Criança , Humanos , América Latina , Modelos Lineares
6.
NeuroRehabilitation ; 41(3): 649-659, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28946594

RESUMO

OBJECTIVE: To generate normative data for the Shortened Version of the Token Test in Spanish-speaking pediatric populations. METHOD: The sample consisted of 4,373 healthy children from nine countries in Latin America (Chile, Cuba, Ecuador, Guatemala, Honduras, Mexico, Paraguay, Peru, and Puerto Rico) and Spain. Each participant was administered the Shortened Version of the Token Test as part of a larger neuropsychological battery. Shortened Version of the Token Test total scores were normed using multiple linear regressions and standard deviations of residual values. Age, age2, sex, and mean level of parental education (MLPE) were included as predictors in the analyses. RESULTS: The final multiple linear regression models showed main effects for age in all countries, such that score increased linearly as a function of age. In addition, age2 had a significant effect in all countries, except Guatemala and Puerto Rico. Models showed that children whose parent(s) had a MLPE >12 years obtained higher score compared to children whose parents had a MLPE ≤12 years in Ecuador, Guatemala, Honduras, Mexico, Paraguay, Peru, Puerto Rico, and Spain. The child's sex did not have an effect in the Shortened Version of the Token Test total score for any of the countries. CONCLUSIONS: This is the largest Spanish-speaking pediatric normative study in the world, and it will allow neuropsychologists from these countries to have a more accurate interpretation of the Shortened Version of the Token Test when used in pediatric populations.


Assuntos
Testes Psicológicos/normas , Criança , Humanos , América Latina , Modelos Lineares , Espanha
7.
Med Biol Eng Comput ; 52(2): 149-58, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24257836

RESUMO

EEG signals have been widely explored in emotional processing analyses, both in time and frequency domains. However, in such studies, habituation phenomenon is barely considered in the discrimination of different emotional responses. In this work, spectral features of the event-related potentials (ERPs) are studied by means of event-related desynchronization/synchronization computation. In order to determine the most relevant ERP features for distinguishing how positive and negative affective valences are processed within the brain, support vector machine-recursive feature elimination is employed. The proposed approach was applied for investigating in which way the familiarity of stimuli affects the affective valence processing as well as which frequency bands and scalp regions are more involved in this process. In a group composed of young adult women, results prove that parietooccipital region and theta band are especially involved in the processing of novelty in emotional stimuli. Furthermore, the proposed method has shown to perform successfully using a moderated number of trials.


Assuntos
Encéfalo/fisiologia , Eletroencefalografia/métodos , Emoções/fisiologia , Potenciais Evocados/fisiologia , Adolescente , Adulto , Algoritmos , Feminino , Voluntários Saudáveis , Humanos , Pessoa de Meia-Idade , Máquina de Vetores de Suporte , Adulto Jovem
8.
Clin Neurophysiol ; 124(9): 1798-806, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23660009

RESUMO

OBJECTIVE: In this study, individual differences in brain electrophysiology during positive and negative affective valence processing in women with different neuroticism scores are quantified. METHODS: Twenty-six women scoring high and low on neuroticism participated on this experiment. A support vector machine (SVM)-based classifier was applied on the EEG single trials elicited by high arousal pictures with negative and positive valence scores. Based on the accuracy values obtained from subject identification tasks, the most distinguishing EEG channels among participants were detected, pointing which scalp regions show more distinct patterns. RESULTS: Significant differences were obtained, in the EEG heterogeneity between positive and negative valence stimuli, yielding higher accuracy in subject identification using negative pictures. Regarding the topographical analysis, significantly higher accuracy values were reached in occipital areas and in the right hemisphere (p < 0.001). CONCLUSIONS: Mainly, individual differences in EEG can be located in parietooccipital regions. These differences are likely to be due to the different reactivity and coping strategies to unpleasant stimuli in individuals with high neuroticism. In addition, the right hemisphere shows a greater individual specificity. SIGNIFICANCE: An SVM-based classifier asserts the individual specificity and its topographical differences in electrophysiological activity for women with high neuroticism compared to low neuroticism.


Assuntos
Afeto/fisiologia , Nível de Alerta/fisiologia , Eletroencefalografia , Transtornos Neuróticos/fisiopatologia , Adolescente , Adulto , Algoritmos , Análise de Variância , Encéfalo/fisiopatologia , Mapeamento Encefálico , Feminino , Humanos , Imaginação/fisiologia , Individualidade , Pessoa de Meia-Idade , Modelos Neurológicos , Lobo Occipital/fisiologia , Adulto Jovem
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