A Modified Hybrid Brain-Computer Interface Speller Based on Steady-State Visual Evoked Potentials and Electromyogram.

BACKGROUND: To enhance the information transfer rate (ITR) of a steady-state visual evoked potential (SSVEP)-based speller, more characters with flickering symbols should be used. Increasing the number of symbols might reduce the classification accuracy. A hybrid brain-computer interface (BCI) improves the overall performance of a BCI system by taking advantage of two or more control signals. In a simultaneous hybrid BCI, various modalities work with each other simultaneously, which enhances the ITR. METHODS: In our proposed speller, simultaneous combination of electromyogram (EMG) and SSVEP was applied to increase the ITR. To achieve 36 characters, only nine stimulus symbols were used. Each symbol allowed the selection of four characters based on four states of muscle activity. The SSVEP detected which symbol the subject was focusing on and the EMG determined the target character out of the four characters dedicated to that symbol. The frequency rate for character encoding was applied in the EMG modality and latency was considered in the SSVEP modality. Online experiments were carried out on 10 healthy subjects. RESULTS: The average ITR of this hybrid system was 96.1 bit/min with an accuracy of 91.2%. The speller speed was 20.9 char/min. Different subjects had various latency values. We used an average latency of 0.2 s across all subjects. Evaluation of each modality showed that the SSVEP classification accuracy varied for different subjects, ranging from 80% to 100%, while the EMG classification accuracy was approximately 100% for all subjects. CONCLUSIONS: Our proposed hybrid BCI speller showed improved system speed compared with state-of-the-art systems based on SSVEP or SSVEP-EMG, and can provide a user-friendly, practical system for speller applications.

Competition between parts and whole: A new approach to Chinese compound word processing.

How compound words are processed remains a central question in research on Chinese reading. The Chinese reading model assumes that all possible words sharing characters are activated during word processing and these activated words compete for a winner (Li & Pollatsek, 2020). The present studies aimed to examine whether embedded component words compete with whole compound words in Chinese reading. In Study 1, we analyzed two existing lexical decision databases and revealed inhibitory effects of component-word frequency and facilitative effects of character frequency on the first components. In Study 2, we conducted two factorial experiments to further examine the effects of first component-word frequency, with character frequencies controlled. The results consistently indicated significant inhibitory effects of component-word frequency. Collectively, these findings support the theoretical proposition that both component words and compound words are activated and engage in competition during word processing. This provides a new approach to compound word processing in Chinese reading and a possible solution to mixed results of character frequency effects reported in the literature. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

An EPR study of the cognitive processes underlying the impact of self-relevant information on emotional word processing.

Using the event-related potentials (ERPs) technique, this study successively presented names (in either a supra- or subthreshold manner) and emotional words to examine how self-relevant cue (self-name) affects emotional word processing in word class judgment task (to determine whether an emotional word is a noun or adjective) and valence judgment task (to determine whether an emotional word is positive or negative). At the suprathreshold condition, self-relevant positive words elicited a more significant Early posterior negativity (EPN) than negative words only in the valence judgment task. In contrast, at the subthreshold condition, self-relevant negative words elicited an enhanced Late positive potential (LPP) than positive words only in the word class judgment task. These results indicate that self-relevant cue affects emotional word processing at both suprathreshold and subthreshold conditions; nevertheless, the effect manifests as self-positive bias at the suprathreshold condition and self-negative bias at the subthreshold condition. The experimental task modulates these dynamics.

Neural correlates of word processing influenced by painful primes.

The administration of painful primes has been shown to influence the perception of successively presented semantic stimuli. Painful primes lead to more negative valence ratings of pain-related, negative, and positive words than no prime. This effect was greater for pain-related than negative words. The identities of this effect's neural correlates remain unknown. In this EEG experiment, 48 healthy subjects received noxious electrical stimuli of moderate intensity. During this priming, they were presented with adjectives of variable valence (pain-related, negative, positive, and neutral). The triggered event-related potentials were analyzed during N1 (120-180 ms), P2 (170-260 ms), P3 (300-350 ms), N400 (370-550 ms), and two late positive complex components (LPC1 [650-750 ms] and LPC2 [750-1000 ms]). Larger event-related potentials were found for negative and pain-related words compared to positive words in later components (N400, LPC1, and LPC2), mainly in the frontal regions. Early components (N1, P2) were less affected by the word category but were by the prime condition (N1 amplitude was smaller with than without painful stimulation, P2 amplitude was larger with than without painful stimulation). Later components (LPC1, LPC2) were not affected by the prime condition. An interaction effect involving prime and word category was found on the behavioral level but not the electrophysiological level. This finding indicates that the interaction effect does not directly translate from the behavioral to the electrophysiological level. Possible reasons for this discrepancy are discussed.

The influence of emotional context on emotional word processing in discourse comprehension: evidence from event-related potential.

This research utilized event-related potential (ERP) recording technology to examine the effect of emotional context on the processing of emotional information in sentences. Three types of emotion-consistent discourse materials (neutral-neutral, positive-positive and negative-negative) were constructed to specifically express neutral, positive and negative emotions, respectively. Each discourse comprised two sentences, with the emotionally significant words embedded at the penultimate position of the second sentence. Participants were asked to read these texts, respond to reading comprehension questions and the ERP amplitude induced by the emotional words was recorded. The results indicated a tripartite interaction in the N400 and Late positive component amplitudes involving emotional context, emotional words and brain hemispheres, observed in both frontal and central brain regions. Notably, there was a significant difference in response to positive words between positive and negative contexts. The findings suggest that emotional context has a substantial effect on the processing of emotional words. Positive words, in comparison to negative ones, are more influenced by emotional context, particularly in the frontal and central regions of the brain.

Análisis de las interacciones entre los actores de la Red de Gestión del Conocimiento, Investigación e Innovación en Malaria de Colombia / Analysis of interactions between actors of the Red de Gestión del Conocimiento e Innovación en Malaria de Colombia

Introducción. La malaria, o paludismo, es una enfermedad de gran impacto en la población colombiana, que debe ser abordada desde el punto de vista del trabajo en equipo de instituciones para el intercambio de conocimiento. Objetivo. Analizar las interacciones de la Red de Gestión del Conocimiento, Investigación e Innovación en Malaria de Colombia. Materiales y métodos. Se hizo un análisis de redes sociales que permitió identificar la proximidad entre los actores y el grado de conocimiento entre ellos; se observaron indicadores de densidad, diámetro, distancia media y centralidad de grado. El corpus documental para el estudio estuvo constituido por 193 documentos técnicos publicados entre el 2016 y el 2021, que fueron analizados empleando técnicas de procesamiento de texto mediante el lenguaje de programación R. La categorización de la red se realizó a partir de cinco variables: atención integral a pacientes, diagnóstico, epidemiología y sistemas de análisis de información en salud, política pública, y promoción y prevención. Resultados. El análisis de las interacciones indicó que la red la conformaban 99 actores, de los cuales 97 (98 %), mostraron más interés en la producción de conocimientos en epidemiología y sistemas de análisis de información en salud, seguido de la categoría de atención integral a pacientes con 79 (80 %). El 54 % de los actores llevó a cabo estudios de promoción y prevención, siendo esta la categoría de menor abordaje. Conclusiones. Este estudio contribuye al fortalecimiento de estrategias clave en la divulgación del conocimiento sobre la malaria en Colombia.

Introduction: Malaria is a disease with a high impact on Colombian population, which must be approached from the point of view of teamwork of institutions for knowledge exchange. Objective: To analyze the interactions of the Red de Gestión del Conocimiento, Investigación e Innovación en Malaria de Colombia. Materials and methods: An analysis of social networks was applied that allowed identifying the proximity between actors and the degree of knowledge between them. Indicators of density, diameter, average distance, and degree of centrality were observed. The documentary corpus for the study consisted of 193 technical documents published between 2016 and 2021, which were analyzed using text mining using the R programming language. The network was categorized based on five variables: comprehensive patient care, diagnosis, epidemiology and health information analysis systems, public policy and promotion and prevention. Results: The analysis of interactions indicated that the network was made up by 99 actors. The main interest in knowledge production was on epidemiology and health information analysis systems (98 % of the actors), followed by the integral patient care (80 % of the actors). On the contrary, the least approached category was malaria promotion and prevention practices (54 % of the actors). Conclusions: In general, this study contributes to the strengthening of key strategies in the dissemination of knowledge about malaria in Colombia.

Quando a forma importa:: o efeito de configuração de mensagens na tomada de decisão / When the frame matters:: message framing effect on decision making / Cuando la forma importa:: el efecto de configuración de mensajes en la tomada de decisión

O presente artigo se propôs a realizar uma revisão da literatura sobre o efeito de configuração na tomada de decisão. O efeito de configuração refere-se ao achado de que as pessoas respondem de forma distinta a diferentes descrições de um mesmo problema. Para tanto, foi explorado o surgimento da teoria dos prospectos (também denominada teoria prospectiva), que deu origem aos estudos sobre o efeito de configuração, considerando as diferentes variáveis usualmente relacionadas ao referido efeito. O avanço dos estudos culminou no achado de diferentes tipos de efeito de configuração (de risco, de objetivos e de atributos), que divergem quanto a definições operacionais, padrões de resultados e teorias para a interpretação. A teoria dos prospectos, entretanto, prestar-se-ia apenas para a análise e a interpretação do referido efeito exclusivamente em um contexto de risco....(AU)

The present paper proposes a literature review about the framing effect on decision making. The framing effect refers to the belief that people answer in distinct ways to different descriptions of the same problem. Thus, the article begins exploring the rise of the prospect theory, responsible for the studies of the framing effect, regarding the distinct variables studied in relation to this effect. The advance of the studies highlighted the different types of framing effect (risky, goal framing and attribute), that disagree in terms of operational definition, result patterns and interpretation theories. The prospect theory nevertheless was found only adequate for analysis and interpretation of the effect solely in a risky context....(AU)

El presente artículo se propone realizar una revisión de la literatura sobre el efecto de configuración en la tomada de decisión. El efecto de configuración se refiere al hallazgo de que las personas responden de forma distinta a diferentes descripciones de un mismo problema. Para tanto, fue explorado el surgimiento de la teoría de los prospectos (también denominada teoría prospectiva), que dio origen a los estudios sobre el efecto de configuración, considerando las diferentes variables usualmente relacionadas al referido efecto. El avance de los estudios culminó en el hallazgo de diferentes tipos de efecto de configuración (de riesgo, de objetivos y de atributos), que divergen en lo referente a definiciones operacionales, estándares de resultados y teorías para la interpretación. La teoría de los prospectos, no obstante, se prestaría solamente para el análisis y la interpretación del referido efecto exclusivamente en un contexto de riesgo....(AU)

Evaluación de resúmenes de textos narrativos y expositivos utilizando análisis semántico latente / Evaluation of narative text and presentation text summaries using latent semantic análisis

El objetivo de este trabajo es identificar un método de evaluación automática de resúmenes realizados a partir de textos de tipo narrativo y expositivo en español. Para llevar a cabo esta tarea se correlaciona la evaluación realizada por tres docentes a 373 resúmenes con los resultados entregados por el análisis semántico latente. Los puntajes asignados por el análisis semántico latente se obtienen utilizando tres métodos 1) Comparación de los resúmenes con el texto fuente, 2) Comparación de los resúmenes con un resumen consensuado 3) Comparación de los resúmenes con tres resúmenes construidos por tres evaluadores. Entre los resultados más relevantes se destacan: a) una alta correlación entre la evaluación realizada por los evaluadores ( 0,63); b) una alta correlación entre los métodos computacionales utilizados ( 0,62) y c) una correlación promedio positiva media-alta entre las evaluaciones realizadas por los docentes y el análisis semántico latente en el segundo y tercer método ( 0,53 en ambos casos y tipos de textos). Ambos métodos presentaron mayor correlación promedio con los evaluadores cuando los textos evaluados eran predominantemente narrativos ( 0,59 y 0,45 respectivamente).

The objective of this study is to identify a method for the automatic evaluation of the summaries developed from narrative and expository Spanish texts. In order to fulfill this task evaluation of 373 summaries carried out by three teachers is correlated with the results delivered by latent semantic analysis. Scores assigned by the latent semanticanalysis are obtained through three methods: 1) Comparison of the summaries with the source text, 2) Comparison of the summaries with a consensuated one, 3) Comparison of the summaries with three summaries developed by three evaluators. The mostrelevant results include: a) a high correlation between assessments by the evaluators (:0.63), b) a high correlation between the computational methods used (:0.62) and c) a positive medium-high average correlation between assessments undertaken bythe teachers and the latent semantic analysis in the second and third method (;0.53 in both cases and types of texts). Both methods presented greater average correlation with testers when the texts evaluated were predominantly narratives (;0.59 and 0.45 respectively).

Segmentación por tópicos en documentos de múltiples párrafos / Segmentation by topics in multiparagraph documents

Detectar automáticamente los límites físicos adecuados de los subtópicos en un documento es una tarea difícil y muy útil en el procesamiento de texto. Existen algunos métodos que intentan resolver este problema, varios de ellos con resultados favorables, aunque presentan algunas deficiencias; además, muchas de estas soluciones dependen del dominio de la aplicación. Se realiza un análisis de dos algoritmos para la segmentación de documentos y se comparan los resultados obtenidos con cada uno de ellos.

To automatically detect the adequate physical limits of subtopics in a document is a difficult but highly useful task in text processing. There is a few methods attempting to solve this problem, several of which have favorable results, although presenting some difficulties; also, many of these solutions depend on application skills. An analysis was made of two document segmentation algorithms and the results from each of them were compared.

Encuentros y desencuentros en la representación objetiva y subjetiva de las fuentes de información / Converging and diverging points in the objective and subjective representation of information sources

Se analizan los puntos de encuentro y desencuentro entre los procesos orientados a la representación objetiva y subjetiva de las fuentes de información. Se indican algunos elementos de la objetividad y subjetividad en la representación de las fuentes. Se examinan semejanzas y diferencias entre el tratamiento y el análisis documental. Se exponen un grupo de reflexiones sobre el análisis de información como proceso que explora la subjetividad contenida en las fuentes

O texto de crianças e adolescentes com depressão maior unipolar / The text of children and adolescents with unipolar major depression

O objetivo deste estudo foi verificar a elaboração e a recontagem de histórias de crianças com o diagnóstico de depressão maior unipolar (DSM-IV, 1997) em um estudo duplo-cego longitudinal controlado com placebo. Fizeram parte do estudo trinta sujeitos com idades entre 10 e 14 anos, randomizados para o uso de fluoxetina ou placebo. Ambos os grupos foram avaliados quanto à elaboração livre de textos orais e escritos e à recontagem de textos (fábulas de Êsopo ou La Fontaine) na etapa 0 (sem uso de medicação) e na etapa 3 (três meses após a introdução de medicação ou placebo). Os textos foram analisados de acordo com o modelo de Kintsch e Van Dijk (1978), baseado no número de macro e microestruturas produzidas e/ou recordadas e nos componentes relativos à superestrutura textual. A este modelo foi acrescida a análise do conteúdo proposicional (positivo, negativo ou neutro). Não foram observadas diferenças significativas com relação a esses critérios entre os grupos ou períodos analisados, nem quanto à produçaõ e/ou recontagem de textos orais ou escritos, mesmo com a melhora da sintomatologia clínica observada por meio da escala CDRS (Poznanski & Mokros, 1996) /The aim of this study was to evaluate the textual production and retelling of children with unipolar major depression (DSM-IV, 1997) in a longitudinal, double-blinded, placebo-controlled study. Thirty subjects, aged between 10 and 14 years, were selected and randomized for the use of fluoxetine or placebo. Both gropus were analyzed regarding to spontaneous oral and written production and to the retelling of the texts (Esopo’s or La Fontaine fables) in the period zero (without medication) and period 3 (three months after starting placebo or fluoxetine). The texts were analyzed according to Kintsch and Van Dijk’s model (1978), taking in account the number of macro and microstructures elaborated and/or recalled and the textual superstructure. We added to this model the proposition-content analysis (positive, negative or neutral). Regarding these criteria, no differences were found amongst the gropus or periods analyzed, neither amongst the oral and written elaborated or retold texts, even after the improvement of clinical symptoms evaluated by CDRS scale (Poznanski and Mokros, 1996)...

Análisis documental y de información: dos componentes de un mismo proceso / Information and document analysis: two components of a same process

Se comparan los conceptos de análisis de información y tratamiento documental sobre la base de sus relaciones y diferencias. Se tratan como parte de un proceso integrador cíclico y sistémico que responde a una serie de necesidades metodológicas, propias de todas las ciencias. Se analizan las exigencias de cada una para su realización. Ambos procesos son componentes esenciales de la práctica cotidiana de los trabajadores de la información

El texto fenomenológico como objeto de análisis de procesos conscientes / The phenomenological text as object of the consciousness processes analysis

El presente estudio forma parte de un proyecto general cuyos objetivos son seleccionar diversos textos que describen la experiencia subjetivos son seleccionar diversos textos que describan la experiencia subjetiva y desarrollar técnicas de análisis que hagan posible su interpretación y representación en términos de la estructura y dinámica de la conciencia. De esta manera se trata de una aproximación cognitiva al texto en primera persona que pretende avanzar en la comprensión de la naturaleza de la conciencia mediante el análisis de las producciones orales o escritas de un tipo muy particular de lenguaje natural, a saber, de ciertos informes en primera persona. El monólogo interior y la psiconarración de la literatura, en particular de la novela contemporánea desde Joyce y Proust muestran y prueban las extraordinarias capacidades del lenguaje para sugerir, describir y analizar estados mentales. Sin embargo no pueden ser objeto de análisis estados mentales. Sin embargo no pueden ser objeto de análisis de procesos conscientes porque son simulaciones. Existe otro tipo de monólogos y soliloquios que llamamos testimonios en los cuales el autor del texto expresa sus propios estados interiores de manera inmediata y franca. Partes muy selectas de estos escritos son llamados "textos" fenomenológicos" y constituyen objetivos más apropiados de estudio. En el presente trabajo se ilustran ampliamente tres tipos de textos fenomenológicos extraídos de diarios, autoexperimentos y transcripciones verbatim de parlamentos obtenidos en la clínica. Un monólogo recogido en el diario de una paciente de Pierre Janet es utilizado para presentar un análisis preliminar del texto consistente en su fragmentación en segmentos y en la atribución a cada segmento de contenidos mentales de acuerdo a una lista de nueve categorías mentales preparadas para ello. El procedimiento se deriva directamente de los métodos de la etología cuantitativa y muestra la posibilidad de acceder a los informes en primera persona de manera empírica y de complementar eventualmente al análisis cualitativo con el cuantitativo. Finalmente se establecen tres características o requisitos para considerar a una narración como "texto fenomenológico" susceptible de un análisis cognoscitivo el cual, a su vez pueda ser usado para desarrollar un modelo del proceso consciente. El método pretende tener aplicaciones en la psicología cognitiva, en la psicopatología y en la psicofarmacología