OK
Here is an interesting video on what learning a foreign language means from the neuronal point of view.
It is in French (with no subtitles) and I don't expect that anbybody can understand what is being told but there
is an interesting graph at 12 minutes 30 that shows the rapid decline of the ability to discriminate the
sounds pronounced by a foreigner past the earliest years of life. And since it is neuronal it is
without remedy obviously.
--
FL