Publicación Oficial de la Sociedad Ecuatoriana de Neurología, de la Liga Ecuatoriana Contra la Epilepsia y de la Sociedad Iberoamericana de Enfermedad Cerebrovascular

Paradigma

 

Diseño y validación de un paradigma para evaluar la atención selectiva, utilizando el software de código abierto “PsychoPy”, aplicable a la Resonancia Magnética Funcional. Design and validation of a paradigm to evaluate selective attention, using the open source software “PsychoPy”, applicable to Functional Magnetic Resonance.

Introduction: Selective attention is a neuropsychological function involved in carrying out activities, from the simplest to the most complex, guiding us towards the search for relevant elements for the achievement of proposed tasks and inhibiting other responses.

Objective: Design and validation of the paradigm to evaluate selective attention.

Methodology: Quantitative study, exploratory-descriptive, experimental. The instrument was designed in three stages: 1) elaboration of the paradigm, 2) validation of the construct and content, 3) Field test and data analysis applied to 18 healthy adults, selected in a non-probabilistic way, between 18 and 30 years old. The paradigm was developed virtually in “PsychoPy”, based on the d2 test and adapted for the Magnetic Resonator.

Results: High scores were found in the evaluation of selective attention and the average time of correct answers is adequate in relation to the amount of work. When analyzing the influence of age and sex with the frequency of correct answers, no statistically significant differences were found.

Conclusions: The selective attention paradigm is a complementary prognostic tool, useful to assess this function, because it has construct and content validity; being a safe, free and easy-to-apply instrument.

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Palabras clave: Adultos, atención selectiva, Ecuador, neuropsicología, Paradigma, RMf,

Keywords: Adults, Ecuador, fMRI, neuropsychology, Paradigm, selective attention,

Propuesta de un paradigma computarizado para valorar memoria de trabajo. Proposal of a computerized paradigm for evaluation of working memory.

A paradigm for evaluating working memory was validated with the use of N-back tasks in a computer program to be applied within Functional Magnetic Resonance (RMF). The study hypothesis is based on the fact that a verbal 2-back difficulty level increases the success in the performance of the task in working memory, valid to be used in RMF. Through a quantitative cross-sectional study, the N-back paradigm was adapted to a PshicoPy computer program. The task consisted of responding to the stimulus or letter that is the same as the one that appeared two places behind (2 back). 4 blocks of 30 seconds each were presented, and 4 blocks of rest of 30 seconds; in total it lasts 4 minutes. To study the validity of the paradigm, an expert validation and a pilot test were carried out with the participation of 18 adult university subjects. The data was tabulated in a spreadsheet, using statistical contingency table tests; and of sensitivity and specificity. The results offered data greater than 80% sensitivity and specificity regarding the subject’s performance before the test, and the validity of the stimuli. It is concluded that the test can be used to assess working memory by means of a computer program, which can also be used in applications such as RMF.

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Palabras clave: Memoria de Trabajo, N-back, Paradigma, PsycoPy, RMf,

Keywords: fMRI, N-back, Paradigm, PsycoPy, working memory,

Validación de un paradigma de razonamiento abstracto para Resonancia Magnética funcional (RMf). Validation of an abstract reasoning paradigm for functional magnetic resonance (fMR).

The paradigms are the experimental tasks that are used to map the brain through functional Magnetic Resonance Imaging. Its previous validation is essential to guarantee a successful record of the cognitive activity. A paradigm of abstract reasoning formed by a task of semantic and visual analogies was validated in young-adults between 18 and 30 years in the city of Cuenca-Ecuador. The paradigm was programmed in PsychoPy 3, a free software for neuroscience experiments. The results indicated that the experimental paradigm was understandable and easy to solve. It was also found that the average response time in the semantic reasoning task was significantly lower than the average resolution time of the visual reasoning task. Therefore, it was possible to establish the number of stimuli and their average exposure time needed for a functional Magnetic Resonance Imaging.

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Palabras clave: Paradigma, PsychoPy, razonamiento abstracto, resonancia magnética funcional, validación,

Keywords: abstract reasoning, Functional magnetic resonance imaging, Paradigm, PsychoPy, validation,

Aspectos Neuropsicológicos de la Resonancia Magnética Funcional.

Cognitive neuropsychology and functional magnetic resonance (RMf) have marked a particularly fertile period in the development of neurosciences. Their clinical value, although incipient, is unquestionable. Integration of these two disciplines allows the registration  of cerebral images related to the neuronal activation of specific areas, providing structural and functional information of the human brain  under normal and pathological conditions. The RMf has important clinical and research applications. For example, pointing the brain  areas needed to be avoided during surgery, or observing the neurofunctional changes that take place with a  pharmacological treatment or neuropsychological rehabilitation. It also permits increasing the knowledge of  neurofunctional bases of different cerebral pathologies. It  is of special interest and importance the selection and implementation of the activation paradigm on functions to be studied, condition that  is required for the correct interpretation of the results. The procedure for RMf allows the study of a specific component in the  cognitive process in response to a specific task. It doesn’t identify the function as a unique feature, but it  identifies neurofunctional patterns. In this  article, the basic theoretical-methodological neuropsychological aspects are described for the implementation of studies by RMf.

 

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Palabras clave: Entrevista, evaluación neuropsicológica, Neuropsicología cognitiva, Paradigma, Patrones  neurofuncionales, resonancia magnética funcional,

Keywords: Cognitive neuropsychology, functional magnetic resonance, Interview, Neurofunctional pattern, Neuropsychological Evaluation, Paradigm,
 
 
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