After suffering a stroke, a woman in the UK started speaking in an accent that sounds Jamaican (or by some accounts, eastern European).
Researchers at Oxford University have found that patients with foreign accent syndrome have suffered damage to areas of the brain that affect speech.
The result is often a drawing out or clipping of the vowels that mimic the accent of a particular country, such as Spain or France, even though the sufferer has limited exposure to that accent. The syndrome was first identified during the Second World War when a Norwegian woman suffered shrapnel damage to her brain. She developed a German accent, which led to her being ostracised by her community.