This has been floating around in my brain for some time now, and I thought I would just plop it down here. Ever get annoyed by folks who travel to, say, Great Britain and come home with a "fake" accent? They sound so stupid and pretentious, don't they? But what if there were a neurological underpinning for their accent acquisition? What if they need to acquire the accent - meaning they need to acquire the motor coordination to make the sounds as if they were a Brit, so that their mirror neurons would fire similarly when listening to someone from the U.K.? I know, a far-fetched neurological idea from a sculptor. And I doubt that fMRI is up to it to look at such subtle differences in brain activity when speaking (or hearing) a word in British or American english.
But, if and when brain imaging resolution is high enough, you could set up to observe someone from the US, say, who is moving to the UK.
1) You would first do a control fMRI brain functioning with their native english, focusing on particular words that have very different sounds (and different mouth/vocal actions required to make the sounds) from British english (or Canadian - think of the word "about"). Also, you would record their speech - a specific statement that would be repeated during the latter portion of the study.
2) Then you would do a similar control (on a different subject, also moving to the UK?) with the British spoken word equivalents.
3) Then, six months to a year in, you would a) record the speech of the subject and compare it to changes from their first recording. b) do an fMRI of the same sounds, and see if there is a difference.
Something like that, anyway....