Personally, I do think the brain is plastic in this sense though. I haven't looked deep enough into it to be a 100% certain. Nevertheless, from all the research summaries I read, I gather that whenever a skill is practiced in a focused manner for 1 to 2 hours, neural plasticity occurs.
I wish there was a literature review around this idea. But I got the feeling that 4 years ago the literature was mostly on clinical patients. Normal people and neural plasticity seems to be researched less well.