English has become the first truly global lingua franca. Even in multilingual Switzerland, English as a lingua franca (ELF) is replacing the four Swiss languages not only in international but also in intra-national communication. What appears at first glance to be a practical solution to communication problems in business, science and education can come at a cost, however. Despite the obvious relevance, there has been very little research into the consequences of millions of speakers having to use a foreign language to conduct business, academic, and other professional communication. As language experts, interpreters and translators play an important role in fostering international communication and have competences and strategies that allow them to cope with speeches and texts that deviate to various degrees from Standard English. Preliminary research nevertheless suggests that the increasing volume of non-native English can lead to cognitive overload and stress for interpreters and translators. The goal of this project is to gain a better understanding of the effects of this globalisation phenomenon. An interdisciplinary team of researchers from the fields of interpreting, translation, and neuropsychology is using various methods to assess the actual cognitive demands associated with processing ELF as compared to Standard English.