[bkfunk]

“Biological” does not mean “genetic”. I believe parent is musing whether there is a neurodevelopmental basis, which of course there is, by all evidence; if you do not hear certain sounds by a young age, you will never be able to speak a language using those sounds with an accent indistinguishable from that of a native speaker. Obviously there is, indeed, a neurological component to that phenomenon.

In the US, the “Irish accent” (scare quotes because there is of course no single accent of Ireland) is fairly well known (that is, watching American TV and movies, you encounter Irish native English speakers more than, say, South African English speakers). And in TFA it says the patient in question lives in England, where of course there is even more exposure to Irish accents.

There must be, I posit, some circuitry that can interpret the phonemes of differently accented English and translate them into whatever latent representation of words or concepts is used for thought and speech production; so it’s interesting to wonder whether what is happening is the wires are getting crossed, as it were, and receptive circuits start connecting to productive circuits that control the speech organs to produce different sounds. What’s more, TFA doesn’t say if it was a good or accurate or even geographically consistent and coherent accent.