[Prevalence of neurocognitive disorders in a rural area of Argentina] / Prevalencia de trastornos neurocognitivos en una región rural Argentina.

Aim: To carry out a cognitive screening to detect cases of Neurocognitive Disorders (NCD) 60 and over years adults and estimate its prevalence in the eastern area of Tucumán. Methods: A neuropsychological assessment was carried out. Groups were formed according to the presence and severity of NCD. Results: 257 subjects participated in the study (X = 69.9 years, SD = 7.2; 60.7% of female gender). The prevalence of neurocognitive disorders was estimated at 51.17% with 90% confidence and a precision (d) of 4%. Main Conclusion: The prevalence exceeded the estimation for Argentina. From the tests it was observed that the lower the educational level and the older the age, the risk of developing neurocognitive disorders would increase. This work demonstrated the ability to develop large-scale epidemiological studies in public health, articulating the activity of the different healthcare centers, given the lack of studies about the matter in our country.

Objetivos: realizar un screening cognitivo para detectar casos de trastornos neurocognitivos (TNC) en adultos mayores de 60 años y estimar su prevalencia en el Este de Tucumán. Métodos: Se realizó una evaluación neuropsicológica de cribado. Para el análisis de los datos se conformaron grupos según la presencia y severidad de TNC. Resultados: 257 sujetos participaron en el estudio (X = 69.9 años; DS=7.2; 60,7% género femenino). Se estimó la prevalencia de trastornos neurocognitivos en 51,17% con un 90% confianza y una precisión (d) del 4%. Conclusión principal: La prevalencia superó los datos estimados para Argentina. A partir de las pruebas se observó que  a menor nivel educativo y a mayor edad,  aumentaría el riesgo para desarrollar trastornos neurocognitivos. Este trabajo demostró la capacidad de desarrollar estudios epidemiológicos a gran escala en el sistema sanitario público, articulando la actividad de los diferentes centros de salud, ante la escasez de estudios de este tipo en nuestro país.

Inhibición de la respuesta: Entrenamiento y efectos vinculados al nivel inhibitorio de base, en niños / Response inhibition: training and effects linked to the level of inhibition in pre-test, in children

Resumen Desde el enfoque no-unitario de la inhibición, se identifican tres procesos inhibitorios: inhibición perceptual, cognitiva y de la respuesta. Esta última permite suprimir conductas prepotentes e inapropiadas para los objetivos en curso. En los últimos años se evaluaron diferentes intervenciones orientadas a optimizar la inhibición de la respuesta durante los inicios de la escuela primaria; sin embargo, los estudios resultan insuficientes para evaluar la eficacia de estas intervenciones sobre el proceso entrenado y otros procesos inhibitorios e identificar las características asociadas a los resultados. En este estudio se propuso analizar la eficacia de un entrenamiento de la inhibición de la respuesta en niños en los primeros años de escolaridad primaria, sobre este proceso y la inhibición perceptual, a corto y largo plazo; y estudiar si variables como la edad y el nivel inhibitorio de base de los participantes se relacionan con los resultados. Participaron 93 niños (de 6 a 8 años), asignados a un grupo de entrenamiento y otro de control, en un diseño experimental con pre-test y dos post-test. Se observaron efectos, atribuibles al entrenamiento, sobre el desempeño de una tarea de inhibición de la respuesta a corto plazo, siendo los niños con un nivel inhibitorio de base más bajo quienes presentaron mayores beneficios. Se discute sobre el aporte de los resultados al modelo no-unitario de la inhibición, el alcance de las intervenciones y el estudio de las características de los participantes en relación con los efectos del entrenamiento.

Abstract From non-unitary perspective of inhibition, three inhibitory processes are identified: perceptual, cognitive and response inhibition. Response inhibition allows suppressing prepotent and inappropriate responses for the current purposes. In the last years, different interventions targeted at optimizing it during the first years of school period. However, the studies are insufficient to understand the efficacy of the interventions on response inhibition and other inhibitory processes, both short- and long-term; and the characteristics that are linked to the results. The goals aims: to analyze the efficacy of a response inhibition training on this process and perceptual inhibition, both short- and long-term, in children in the first years of elementary school; and to analyze if the relationships of age and the level of inhibition in pre-test are related to the results. The participants (93 children, from 6 to 8 years old) were assigned to a training or a control group, in an experimental design, with a pre-test and two post-tests. We observed effects in the short term on children's performance on a response inhibition task. The children who benefited more from the intervention were those who started the intervention with a lower level of inhibition. We discuss the contribution of these results to non-unitary perspective, the scope of the interventions and the study of the participants' characteristics related to the results.

Cognitive flexibility in adulthood and advanced age: Evidence of internal and external validity.

Aging causes changes that affect functioning of cognitive processes such as cognitive flexibility (CF). Given it allows changing both behavior and thinking in dynamic contexts, it constitutes an essential trait of adaptive, goal-oriented behavior. Despite its importance, specific techniques to evaluate CF in older adults are lacking. The goal of this article is to describe and comparatively analyze the functioning of CF in a sample of 169 individuals representing three age groups-younger-age, middle-age and advanced-age adults-by obtaining evidence of internal and external validity. Using a correlational and cross-sectional research design, four studies were conducted in order to evaluate construct validity-fulfillment of experimental paradigm criteria and contrast between groups and tests with different methods. In addition to the Fingers Task, the study used the CAMBIOS Cognitive Flexibility Test, TAC's Conjunction Visual Search Task (which evaluates perceptual inhibition) and a verbal fluency task with changes. The results provide evidence of the functioning of CF in adulthood and advanced age, which has implications for neurocognitive clinical evaluation in these stages of life. Additionally, evidence was obtained in favor of the concurrent validity of the instruments used to measure CF, contributing to the solidity of future studies on this executive function.

The Change Processes in Selective Attention during Adulthood. Inhibition or Processing Speed?

Selective attention is involved in multiple daily activities. Several authors state that it experiences a decline after 20 years, although there is no agreement regarding the cognitive processes that explain it. Two theories dominate the discussion: The theory of inhibitory inefficiency and the theory of processing speed. At the same time, it has been suggested that there could be complementary relations between both; however, it is not clear what the contribution of inhibition and processing speed is on the changes of selective attention. Therefore, the present study proposes to analyze this contribution, in adults between 20 and 80 years old. To assess selective attention and inhibitory control, two indices of a visual search task were obtained in which participants must identify a target stimulus among a set of distracting stimuli. To evaluate the processing speed, a response speed task was used. The main results indicate that, from the age of 60, a gradual decrease in selective attention begins and that this decline can be largely explained by a decrease in processing speed and inhibitory control. We discuss about the literature on the development of selective attention, the contribution of processing speed, and the inhibitory inefficiency hypothesis.

Relaciones conceptuales: comparación entre Niños, Adultos Jóvenes y Adultos Mayores / Conceptual relationships: comparison between Children, Young Adults and Older Adults Artículo barra lateral

El objetivo general del presente trabajo fue estudiar qué tipos de relación conceptual utilizan niños en edad escolar, adultos jóvenes y adultos mayores, ya que se presume que a lo largo del desarrollo varía la preferencia por los tipos de relación conceptual; no obstante, los estudios sobre el tema son escasos y sus resultados son divergentes. Para esto, 226 niños de 6 a 12 años, 300 adultos de 20 a 40 años, y 300 adultos mayores de 60 años realizaron una tarea de producción de atributos de conceptos de seres vivos y no vivos. En dicha tarea, los participantes proporcionaron atributos a partir de conceptos tales como "hormiga" y "pirámide". Los atributos fueron codificados según fuesen taxonómicos ("es un animal"), perceptivos ("es largo") o temáticos ("se encuentra en Egipto"). Los resultados, producto del análisis de comparación de medias, indican que la producción de atributos taxonómicos fue significativamente mayor para los adultos jóvenes que para los adultos mayores y los niños, cuya producción taxonómica fue pareja. En cuanto a la producción temática, esta fue alta y homogénea en los tres grupos de edad. Por último, para el dominio de los seres no vivos, los atributos resultaron en su mayoría temáticos y perceptivos, y para el de los seres vivos, mayormente perceptivos. Se concluye que el uso o preferencia por las relaciones conceptuales varía a lo largo del desarrollo, siendo las taxonómicas más inaccesibles para los niños y los adultos mayores, y menos preponderantes tanto en seres vivos como no vivos

The general aim of this paper was to study what types of conceptual relations are used by school-age children, young adults and old adults, since it is presumed that throughout development the preference for the types of conceptual relations varies, but studies on the subject are scarce, and their results are divergent. For this, 226 children aged 6 to 12 years, 300 adults aged 20 to 40, and 300 adults over 60, performed a feature production task of concepts from the living and the non-living domains. In this task, participants provided attributes from concepts such as "ant" and "pyramid". The attributes were coded according to whether they were taxonomic ("it is an animal"), perceptual ("it is long") or thematic ("it is found in Egypt"). The results from the analysis of variance indicate that the production of taxonomic attributes was significantly higher for young adults than for older adults and children, whose taxonomic production was even. In terms of thematic production, it was high and homogeneous in all three age groups. Finally, for the non-living things domain, the attributes were mostly thematic and perceptive, and for the living beings, mostly perceptive. It is argued that the use or preference for conceptual relations varies throughout development, with taxonomic relations being more inaccessible to children and older adults, and less prevalent for living and non-living things

Fructose malabsorption in asymptomatic children and in patients with functional chronic abdominal pain: a prospective comparative study.

The objective of this prospective cohort study was to compare fructose malabsorption in patients with functional chronic abdominal pain and in healthy children. The sample was divided into two groups: asymptomatic children and pain-predominant functional gastrointestinal disorders according to the Rome IV criteria. All children were tested for fructose malabsorption by a standardized breath hydrogen test. Hydrogen and methane were measured and the test was presumed positive when it exceeded 20 ppm above baseline. If positive, patients were given a low-fructose diet and the response was evaluated. One hundred five children were included (34 healthy children, 71 with functional chronic abdominal pain), with similar demographic characteristics in both groups (35.2% male, age 9.5 ± 2.8 years). Hydrogen levels in breath were tested through a hydrogen test for fructose demonstrating malabsorption in 58.8% of healthy children (95%CI 40.8%-76.8%) and in 40.8% of children with chronic abdominal pain (95%CI 28.7%-53.0%), removing those who had bacterial overgrowth. Twenty-one of 31 patients with symptoms and a positive test (72.4%) reported an improvement on a low-fructose diet.Conclusion: Fructose malabsorption is more common in asymptomatic children than in patients with chronic abdominal pain. Better standardized test conditions are necessary to improve accuracy of diagnosis before using this test in clinical practice. What is Known: • Although fructose malabsorption is believed to be related with chronic abdominal pain, high-quality evidence is lacking. • Concerns have raised regarding the use of breath hydrogen test for fructose malabsorption in children with chronic abdominal pain. What is New: • Fructose malabsorption is not more common in children with pain-predominant functional gastrointestinal disorders than in asymptomatic children. • Improvement in symptoms with low-fructose diet may indicate that, although patients with pain-predominant functional gastrointestinal disorders did not have a higher percentage of malabsorption, they had greater fructose intolerance.

Cognitive functioning: is it all or none?

Under various circumstances, the cognitive system operates in a global manner that is not very precise and barely discriminatory. This form of operating has been described via a general principal that Diamond (Developmental Psychology 45:130-138, 2009) has denominated the All or None Hypothesis. This author has described a set of corollaries derived from this hypothesis that make it possible to verify it in each one of these domains. Although there is evidence of the global and non-discriminate way in which the cognitive system operates in populations of children, to date, there are no studies that have examined whether this mode of operation is also present in populations of adults. Researchers have yet to determine whether these corollaries apply to middle-aged adults. For this reason, this is the current study's principal objective. A sample of 73 participants with ages ranging from 18 to 57 of both genders was evaluated. A modified version of the arrows test in Davidson et al. (Neuropsychologia 44:2037-2078, 2006) was used to analyze the three corollaries. The results obtained in this study can be interpreted as evidence in favor of the corollaries analyzed herein. Furthermore, they indicate that adult populations have a global response mode that is barely differentiated and that is activated by default in the face of problems and situations that demand behaviors and/or thoughts that are not very analytical and differentiated. However, in contexts that demand greater discrimination, this global mode is substituted by a controlled mode that requires greater cognitive effort and more differentiated processing.

Spanish semantic feature production norms for 400 concrete concepts.

Semantic feature production norms provide many quantitative measures of different feature and concept variables that are necessary to solve some debates surrounding the nature of the organization, both normal and pathological, of semantic memory. Despite the current existence of norms for different languages, there are still no published norms in Spanish. This article presents a new set of norms collected from 810 participants for 400 living and nonliving concepts among Spanish speakers. These norms consist of empirical collections of features that participants used to describe the concepts. Four files were elaborated: a concept-feature file, a concept-concept matrix, a feature-feature matrix, and a significantly correlated features file. We expect that these norms will be useful for researchers in the fields of experimental psychology, neuropsychology, and psycholinguistics.

Evolución de la categorización semántica en adultos mayores con diagnóstico de DCL-A y DTA y sin patología neurológica / Evolution of semantic categorization in older adults with and without neurological disease

Tradicionalmente la memoria semántica ha sido definida como un tesoro mental que almacena información sobre las palabras, su significado, como así también la relación entre ellas, los hechos y los conceptos. Una de las vías principales para explicar cómo se organiza la información en la memoria semántica (MS) es a través de categorías. La demencia tipo Alzheimer (DTA) suele estar caracterizada por un deterioro en la memoria episódica. Sin embargo, se debate en torno al deterioro de la misma, en qué momento aparece, a qué se debe y si hay una pérdida diferencial en distintos momentos de la enfermedad. El objetivo del trabajo que se informa fue analizar los procesos de categorización semántica en adultos mayores sanos comparándolos con dos grupos de personas con patologías neurológicas: uno con diagnóstico de deterioro cognitivo leve (DCL) y otro con demencia tipo Alzheimer (DTA), emparejados por edad, nivel educativo y género. Para ello, se utilizaron tareas tradicionales para evaluar la memoria semántica y también un método novedoso, el DISTSEM, que permite evaluar las estimaciones que realizan las personas de las distancias semánticas entre los conceptos. Los resultados mostraron que el grupo de personas sin patología tuvo un rendimiento superior en todas las tareas en comparación con los grupos de personas con patología neurológica. Por otro lado, el grupo con DTA mostró un deterioro semántico afectando en primer lugar a la categoría seres vivos. El DCL preservó la estructura categorial sólo con pequeñas intrusiones. El DISTSEM mostró ser un instrumento adecuado para la discriminación entre sujetos sanos y DTA.

Traditionally, semantic memory has been defined as a mental trove that contains organized information about words and their meaning, as well as relationships between words, facts and concepts.There are different ways of explaining how the information in such memory system is represented and organized. One of the main ways of explaining this organization is through categories. Categorization starts the very moment that any sensorial perception is associated to an abstract category; it is the ability to organize information in equivalence classes, and it is very important because it allows us to summarize the information that we gather through our senses and thus facilitate its manipulation. Alzheimer's disease (AD) is the main cause of dementia among older adults, and it is one of the most pressing sanitary, social and cultural problems of the present times. The main risk factor for the illness is age, for its prevalence augments exponentially from 65 to 85 years old, and due to the rise in life expectancy it is considered that it might be transformed into a world-wide epidemic in the coming years. The start of the illness is insidious and slowly progressing, and it is characterized by a loss of episodic memory from its beginnings. With respect to the deterioration of semantic memory in AD, a debate has arisen about its mode of presentation, its causes, and whether there is a differential loss of categories (live or non-live beings) in different moments of the illness. During the 90s, Petersen proposed the concept of mild cognitive impairment (MCI) to label the subjects with a functional cognitive impairment insufficient to diagnose a dementia syndrome. The importance of this syndrome is that between 8 to 15% of those who suffer it evolve to AD annually, while in the general population this evolution is only from 1 to 2%. However, there is a great controversy about the validity and scope of the term MCI, for its etiology can be very varied and it is very difficult to predict its evolution. There are different sub-kinds of MCI, and the amnesic form is the more likely to evolve into AD, for its main characteristic is the subjective deterioration of memory corroborated by standardized test by reference to normative data for the same age and educational level of the subject. The other cognitive functions not present alterations. The main objective of this work was to analyze the semantic categorization processes in healthy older adults comparing them with two groups of people with neurological pathologies, one with diagnosis of MCI and the other with AD, matched by age, educational level and gender. To evaluate this categorization process, two traditional tasks were used together with a novel method, the DISTSEM, which allows the evaluation of the estimation made by people about the semantic distance among a set of given concepts. The results showed that the group of people without pathologies had a superior performance in all the tasks in comparison with the groups of people with neurological pathologies. On the other hand, the group with AD showed a semantic impairment which affected in the first place the category of live beings, which was evident in the all the tasks. The MCI preserved the categorical structure with only minor intrusions. The DISTSEM has shown itself to be a valuable instrument that allows the discrimination between healthy subjects and those with AD. It is expected that this work can provide empirical evidence relevant to the debate surrounding semantic memory, for studies in patients with brain injury offer key information to examine the organizing models of such memory.

El paradigma stop signal como medida de inhibición conductual / The Stop Signal Paradigm: a measure of behavioral inhibition

El Paradigma de la Señal de Parar, Stop Signal en inglés, es uno de los procedimientos más utilizados para medir el control inhibitorio. Su amplia difusión se explica por dos motivos: su extensa aplicación en el ámbito de la neuropsicología clínica y, porque aporta un índice -el tiempo de frenado- que no se obtiene con otros paradigmas o procedimientos. Esta medida, refiere al tiempo que necesita el individuo para inhibir una respuesta preponderante. El cálculo del índice deriva de un modelo clásico de inhibición, el "Modelo de Carrera de Caballos". Sin embargo, el modelo no ha sido suficientemente difundido en nuestro medio, debido a la complejidad de los análisis matemáticos de base y a que la bibliografía disponible en español en este tema es casi inexistente. Por ello, el objetivo de este trabajo es efectuar una revisión sobre este método y presentar algunas de sus aplicaciones en la neuropsicología clínica y de la psicopatología, tales como para el trabajo con pacientes con trastorno bsesivo compulsivo, adicciones, y trastorno de atención, entre otros. MÉD.UIS. 2014;27(3):89-98.

The Stop Signal Paradigm is one of the most used procedures for measuring the inhibitory control. Their widespread diffusion is due to two reasons: its extensive application in the field of clinical neuropsychology and because it provides an index-braking time-that is not accessible with other paradigms or procedures. This index is defined as the time required for inhibiting a dominant response. The method used to calculate this measure is based on a classical model of inhibition: the "Horse Race Model". However, their diffusion is limited in our environment because the available literature in Spanish is poor due to the complexity of mathematical analysis involved. Therefore, the aim of this work is to carry out a review of this method and present some of its applications in the field of clinical neuropsychology and psychopathology, such as working with patients with obsessive compulsive disorder, addictions, and attention disorder, among others. MÉD.UIS. 2014;27(3):89-98.

Análisis de tareas de fluidez verbal en enfermos de alzheimer y adultos sanos

Las tareas de fluidez verbal son muy utilizadas para evaluar el funcionamiento cognitivo. Suelen dividirse en semántica y en fonológica; la primera requiere evocar palabras de una categoría dada y la segunda, palabras que empiecen con una determinada letra; en ambos casos, en un tiempo limitado. En dichas tareas intervienen la búsqueda y la recuperación en la memoria semántica, y el funcionamiento ejecutivo. Para estudiar esas funciones cognitivas en la demencia tipo Alzheimer, se utilizaron tareas de fluidez verbal semántica (animales) y fonológica (palabras que comienzan con p) en 40 adultos sanos y 31 pacientes con Alzheimer probable, equiparados en edad, género y nivel educativo, ya que han mostrado ser instrumentos sensibles al daño cognitivo que presentan pacientes con esa patología. Se analizaron la cantidad de palabras correctas, el tamaño de los clusters (agrupamientos según criterios semánticos o fonológicos) y la cantidad de switching (cambios entre agrupamientos). Para analizar la comparación entre grupos se utilizó una Prueba T para muestras independientes. Se encontraron diferencias significativas en ambas tareas en la cantidad de palabras (p < .001) y en la de switching (fluidez semántica: p < .001 y fonológica: p = .005), pero no en el tamaño de los clusters, lo cual daría cuenta de una falla ejecutiva en los pacientes con demencia tipo Alzheimer. Estos resultados aportan evidencia favorable a la idea de que un déficit ejecutivo, y no sólo de memoria, es característico de dicha patología.(AU)

Verbal fluency tasks are widely used to assess cognitive functioning, due to its simplicity and ease of administration. They are divided into semantic and phonemic, and require the recall of words of a given category and words that begin with a certain letter, respectively, in a limited period of time. Both tasks involve search and retrieval in semantic memory, and executive functioning. In order to study these cognitive functions in Alzheimer's disease, semantic (animals) and phonemic (words beginning with p) fluency tasks were applied to 40 healthy adults and 31 Alzheimer's disease patients, matched for age, gender and educational level, as these tasks have proven to be sensitive to the cognitive impairment characteristic of this disease. We considered the number of correct words generated, the mean cluster size and the number of switches. To analyze the differences between groups we used a t-test and found that the number of correct words generated (p < .001) and the number of switches (semantic fluency: p < .001; phonemic fluency: p = .005) were statistically different in both tasks, whereas no differences were found regarding the mean cluster size. These results show an executive failure and, therefore, bring evidence that favors the idea that an executive impairment, and not only a mnesic one, is characteristic of this disease.(AU)

Análisis de tareas de fluidez verbal en enfermos de alzheimer y adultos sanos / Analysis of verbal fluency tasks in alzheimer's disease patients and healthy adults

Las tareas de fluidez verbal son muy utilizadas para evaluar el funcionamiento cognitivo. Suelen dividirse en semántica y en fonológica; la primera requiere evocar palabras de una categoría dada y la segunda, palabras que empiecen con una determinada letra; en ambos casos, en un tiempo limitado. En dichas tareas intervienen la búsqueda y la recuperación en la memoria semántica, y el funcionamiento ejecutivo. Para estudiar esas funciones cognitivas en la demencia tipo Alzheimer, se utilizaron tareas de fluidez verbal semántica (animales) y fonológica (palabras que comienzan con p) en 40 adultos sanos y 31 pacientes con Alzheimer probable, equiparados en edad, género y nivel educativo, ya que han mostrado ser instrumentos sensibles al daño cognitivo que presentan pacientes con esa patología. Se analizaron la cantidad de palabras correctas, el tamaño de los clusters (agrupamientos según criterios semánticos o fonológicos) y la cantidad de switching (cambios entre agrupamientos). Para analizar la comparación entre grupos se utilizó una Prueba T para muestras independientes. Se encontraron diferencias significativas en ambas tareas en la cantidad de palabras (p < .001) y en la de switching (fluidez semántica: p < .001 y fonológica: p = .005), pero no en el tamaño de los clusters, lo cual daría cuenta de una falla ejecutiva en los pacientes con demencia tipo Alzheimer. Estos resultados aportan evidencia favorable a la idea de que un déficit ejecutivo, y no sólo de memoria, es característico de dicha patología.

Verbal fluency tasks are widely used to assess cognitive functioning, due to its simplicity and ease of administration. They are divided into semantic and phonemic, and require the recall of words of a given category and words that begin with a certain letter, respectively, in a limited period of time. Both tasks involve search and retrieval in semantic memory, and executive functioning. In order to study these cognitive functions in Alzheimer's disease, semantic (animals) and phonemic (words beginning with p) fluency tasks were applied to 40 healthy adults and 31 Alzheimer's disease patients, matched for age, gender and educational level, as these tasks have proven to be sensitive to the cognitive impairment characteristic of this disease. We considered the number of correct words generated, the mean cluster size and the number of switches. To analyze the differences between groups we used a t-test and found that the number of correct words generated (p < .001) and the number of switches (semantic fluency: p < .001; phonemic fluency: p = .005) were statistically different in both tasks, whereas no differences were found regarding the mean cluster size. These results show an executive failure and, therefore, bring evidence that favors the idea that an executive impairment, and not only a mnesic one, is characteristic of this disease.

Evaluación de las redes semánticas de conceptos académicos en estudiantes universitarios / Semantic network assesment of academic concepts in undergraduate students

La Teoría Extendida de la Propagación de la Activación es uno de los modelos más aceptados para representar la información almacenada en la memoria a largo plazo. En dicho modelo los conceptos no poseen significado de manera aislada sino que lo adquieren por su posición en la estructura reticular. El objetivo de este trabajo es comunicar los resultados de la aplicación del método de evaluación de distancias semánticas (Distsem) sobre nueve conceptos de la asignatura psicología cognitiva en tres instancias, individual inicial, grupal e individual final. Participaron 225 estudiantes del 3er año de psicología (UNMDP) que cursaban la asignatura. Se solicitó a los alumnos estimar la proximidad entre pares aleatorizados de dichos conceptos y luego se aplicó un conjunto de procedimientos de análisis de redes sociales. Los resultados mostraron que las redes semánticas de los alumnos evolucionaron favorablemente en la segunda instancia individual gracias a la interacción grupal. Las conclusiones sugieren una fuerte asociación entre conocimiento inicial y la influencia ejercida en el producto grupal y permiten describir la evolución de las redes(AU)

The Extended Theory of the Propagation of the Activation is one of the more accepted models to represent the information stored in the long term memory. In this model isolated concepts do not have meaning but they acquire it by their relation with the others. The aim of this paper is to communicate the results of an experience in which it was applied a method to estimate the semantic distances (Distsem) between nine concepts of the subject cognitive psychology in three instances, individual initial, group and individual final. The participants were 225 students from third year of the career of psychology (National University of Mar del Plata) that were taking the course of cognitive psychology. Subjects were asked to estimate the proximity between random pairs of concepts and then it was applied a set of Social Network Analyses routines. The results show that the student´s semantic networks changed positively in the second individual instance thank to group interaction. The conclusions suggest an association between initial knowledge and the influence exerted in the group product and allow describing the evolution of the networks(AU)