xénoglossie ou maladroit

The Neurocritic—which looks like a wonderful blog about cognitive science, recommended by Marginal Revolution, has an excellent primer and reporting on the curious phenomena of people all of a sudden (usually after a trauma) being able to speak with some fluency a foreign language that they’ve no prior acquaintance with.
This xenoglossy (or xenolalia) manifests itself in different forms, seemingly unique to that individual speaking in tongues, and sometimes attributed to past-life regression or other paranormal activity—though examining the mental mechanics is just as tantalising. A recent case reveals that eloquence is not always included in the package. After developing an arterial-flow problem, an Italian man began remembering the fragments of French he’d picked up three decades prior while courting a girl. Although still able to speak perfectly good Italian, the man insisted on communicating in broken French, albeit delivered at a rapid and articulate pace of someone very confident in his lingual skills.