I don’t know about the brain but it’s good for the final results in my experience coding, writing and composing (orchestral music). The results are better and it takes less time if I start with pen and paper before “committing” to the computer. One of my favorite authors Jennifer Egan also writes fiction on paper (non-fiction articles still on the computer). More thoughts: https://www.phpied.com/starting-in-the-analog-domain/