Six articles combining the study of bilinguals and neuroimaging techniques are discussed. The objective is to seek for contributions from neuroimaging studies for the understanding of what goes on in the bilingual brain that processes two languages, and of what goes on, comparatively, in terms of brain activation of each language. Studies show that highly proficient bilinguals activate the same areas in the brain for both the first and second languages. This indicates that the second language becomes part of the speaker's procedural knowledge.