Informative and well crafted piece, Kristina.

Writing is a component of language (in neuroscience) which also encompasses speaking, reading, comprehension, calculation, repetition and naming of objects.

Yes, there are specific language areas in the brain, e.g. Broca's area and Wernicke's area.

Nonetheless, the uniqueness and complexity of human language lie largely in the fact that our language is a beautiful symphony of different regions of the brain, each one playing its part perfectly.

So, when you write, the other components of language are also sharpened.