When we consider our language, it seems unified and indivisible. We hear a word, attach meaning to it, and use other words to reply. It’s effortless. It seems part of the same unified language sphere. … The seeming unity of language is really the work of different parts of the brain, which shift and change over time, and which fracture into receptive and expressive parts.
Taken from : “Buddhism and The Brain” (see my “Neuroscience” page!)