Karen Butler woke up from dental surgery with an accent from a faraway place.
After the anesthesia wore off, the Indiana-native-turned-Oregon-resident was perplexed to hear her American English suddenly shift to a hodgepodge of British, Irish and European pronunciations, according to a National Public Radio piece.
Considering her speech change temporary, Butler's doctor suggested it would go away after the swelling in her mouth reduced. But the accent stayed well after she recovered.
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Doctors hypothesize Butler experienced a small stroke while under anesthesia, resulting in her developing foreign accent syndrome (FAS), a neurological disorder that alters the intonation and pitch of a person's speech.
To listeners, people with FAS sound like non-natives producing another culture's take on a given language. But evidence suggests the ears of others might make new pronunciations seem more foreign than they really are. In essence, a woman with FAS who seems to speak English in a Scottish accent is unlikely to sound so to linguists.
It's also false to assume someone with FAS suddenly knows a foreign language, as the condition has nothing to do with acquiring new languages, but rather modifying existing ones.
In the past, FAS was thought to originate from mental problems, which delegitimized people's symptoms and gave rise to fewer treatment options. One high-profile case of FAS surfaced during World War II when a Norwegian woman recovered from a head injury to realize she spoke her native tongue with an uncontrollable German accent, resulting in her community shunning her, as recounted in a Chronicle of Higher Education article.
But research shows a neurological basis for the condition, specifically from anterior lesions in the left hemisphere of the brain associated with language, according to one research analysis. The same article concluded that FAS is a "disruption of automatized speech control processes," or a form of apraxia that restricts speech.
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Other researchers agree that physical, not mental, impairment is most likely to blame. They argue that altering the physical production of speech - the movements of the tongue, lips and mouth - makes the pronunciation of vowels and consonants sound foreign. There's also research suggesting damage to the cerebellum might affect FAS, too.
Brought about by brain damage from stroke, head injuries or disease, FAS might be reversible with intensive speech therapy.
But for Butler, who has grown fond of her strange accent, FAS has given her a new identity she now embraces.