Bump feeling is out since about a century, now it is called (if you don't recollect what they did exactly) "neural imaging" and it is often more than just MRI. MRI shows the structures, other methods show the activity distribution during spefific tasks.
More seriously, 'bump feeling' was the wrong approach, for the shape of the head doesn't change with practise in a certain field, only that part of the brain which is active during the exercise grows larger. That's different from exercising muscles. Schwarzenegging shows at the first glance. Musicians must rely on bulging instrument cases for impression management.

Wolfgang