Oliver Sacks wrote a book “The Man Who Mistook His Wife For A Hat” which is a fascinating, possibly frightening, but very human book about some of the patients that he had the good fortune to meet and understand. It explores or illustrates a number of different dimensions of neurological “effects”, e.g. deficits, excesses and the like. I have in my mind that one of the stories in there involved language, so to a great extent I am not surprised.
The brain has very specific areas for very specific actions and failure or impact on one of those areas causes an effect on that very specific activity. For example, the eponymous Man had a visual agnosia which meant that he failed to assemble the visual information that he could see perfectly well into an abstracted idea. When he saw a glove, he described it once as an object with five “out-pouchings” without being able to recognize that it would perfectly fit his hand and was clearly a glove.
It would not surprise me at all to find that language is treated in one place but that second or third languages are slightly differently stored and if there is interference going on in the first language area, your brain resorted to that other area to find the words.
Completely fascinating. I’d also say that Oliver Sacks’ book is also completely fascinating but potentially a bit scary for those of us with a little danger lurking in our heads.