I have to be honest in saying I don't know the science here. I just personally know that I feel a difference in my mental capacity when I switch from programming to writing. That's all that point is about it.
Now whether we actually 'switch modes' or not would be relevant. I notice a difference. In fact, sometimes I get the feeling that I have more than just two 'modes'. For example:
- bean-counting/organizing - writing/verbal - coding/logic - research/reading
I sometimes have a day where I can be fully productive, but I simply cannot be motived to perform in some of the above modes...
I wonder if there's solid science on this and if these really are different modes.