Second language teaching methods have undergone constant innovation since the mid-twentieth century. However, this has not brought the desired results, suggesting the need to address other crucial factors as yet unexplored and particularly to understand how the brain learns and how language functions in the learning brain. This article examines several schools of thought from brain science and the science of the mind from the perspective of their potential relevance to language learning. The task is not without difficulty, given the enormous volume of available knowledge, requiring not only a thorough analysis of the scientific production but also, above all, a precise selection of material that can be integrated into the field of linguistics applied to the teaching of language, both in terms of research and methodological approaches. We will analyze concepts, theories and paradigms related to the fundamental capacities of the brain, such as perception, emotion, memory and language, in order to better understand how they function in the second language learning processes of as well as raising a series of questions that could be usefully addressed by future researchers in the field of applied linguistics. Our interest is to reflect on how this knowledge can offer new theoretical frameworks on which to build more effective second language teaching approaches and strategies.