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The Advection-Diffusion Reaction (ADR) equation appears in many problems in nature. This constitutes a general model that is useful in various scenarios, from porous media to atmospheric processes. Particularly, it is used at the interface between two fluids where different types of instabilities due to surface mobility may appear. Together with the ADR equation, the Darcy-Brinkman model describes the phenomena known as fingering that appear in different contexts. The study of this type of system gains in complexity when the number of chemical species dissolved in both fluids increases. With more solutes, the increasing complexity of this phenomenon generally requires much computational power. To face the need for more computational resources, we build a solver tool based on an Alternating Direction Implicit (ADI) scheme that can be run in Central Processing Unit (CPU) and Graphic Processing Unit (GPU) architectures on any notebook. The implementation is done using the MATLAB platform to compare both versions. It is shown that using the GPU version strongly saves both resources and calculation times.

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This article describes a chronometric experiment of digit classification with masked primes. EEG experiments have shown that the subliminal prime activates the cortex prior to the target signal, thusly modifying the response: Congruent primes lead to faster correct answers, while incongruent primes result in slower response. It is noticed that incorrect answers show an inverted effect: A congruent prime inhibits incorrect answers, and the reverse for incongruent primes. Within the evidence accrual paradigm, it is suggested that the prime activity in the motor cortex effectively behaves as a shift in the decision threshold. This model assumption is consistent with our experimental findings. The correct and incorrect answers and the error percentage are discussed.

Existe un efecto inhibitorio en experimentos de identificación de objetos cuando dicho objeto ha tenido que ser, previamente, ignorado. Desarrollamos un experimento en el que el prime es un estímulo numérico visible y la tarea está diseñada para inhibirlo explícitamente. En nuestro experimento, los estímulos son dígitos y la tarea consiste en dos decisiones consecutivas: una sobre el prime y otra sobre el target. La mitad de los primes están en formato italics y, sobre éstos, el participante debe abstenerse de responder. Nuestros resultados coinciden con los de experimentos de reconocimientos de objetos: la respuesta al target es más lenta cuando el prime debió ser ignorado. Sin embargo, este comportamiento desaparece, y llega a invertirse, si se reduce el lapso entre los estímulos. Por otro lado, encontramos que el tiempo de respuesta del target depende de la coincidencia (o no) de la mano involucrada para resolver ambas tareas.