La atención selectiva es la función cognitiva que orienta la atención hacia los objetos o estímulos que resultan relevantes evitando la distracción frente a aquellos que son irrelevantes. En general la literatura indica que el desempeño de la atención selectiva mejora notablemente con la edad, sin embargo, las diferencias vinculadas a esta variable no se cumplen para todas las condiciones de cantidad de estímulos distractores ni para todos los grupos de edad. Asimismo, aun no se ha explorado la contribución del control inhibitorio y la velocidad de procesamiento a esta mejora progresiva. Por este motivo, y debido a la escasez de estudios en población infantil, se propuso analizar la contribución relativa de la velocidad de procesamiento y de la inhibición al desempeño en una tarea de atención selectiva y búsqueda visual en esta etapa evolutiva. Para ello, se administró una tarea de búsqueda de conjunciones y una tarea simple de velocidad de respuesta a 295 niños de 6 a 13 años de edad. Los resultados permitieron plantear dos conclusiones principales: por un lado, que la atención selectiva mejora consistentemente durante la niñez y, por otro lado, que no existe un mecanismo general y exclusivo capaz de explicar estas diferencias durante esta etapa vital. Así, tanto la velocidad de procesamiento como el control inhibitorio contribuyen al desarrollo de la atención selectiva y ambos mecanismos cognitivos actúan de manera complementaria más que excluyente.

The aim of this study was to discriminate the differential contribution of different inhibitory processes -perceptual, cognitive and behavioral inhibition- to switching cost effect associated with alternation cognitive tasks. A correlational design was used. Several experimental paradigms (e.g., Stop signal, visual search, Stemberg´s experimental and Simon paradigm) were adapted and included in a computerized program called TAC (Introzzi & Canet Juric, 2014) to the assessment of the different cognitive processes. The final sample consisted of 45 adults (18-50 years). Perceptual and behavioral inhibition shows moderate and low correlations with attentional cost, cognitive inhibition shows no relation with flexibility and only perceptual inhibition predicts switching costs effects, suggesting that different inhibitory processes contribute differentially to switch cost. This could be interpreted as evidence to Attentional Inertia Theory main argument which postulates that inhibition plays an essential role in the ability to flexibly switch between tasks and/or representations.

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.