Foreign Accent Syndrome (FAS) is a motor speech disorder which causes patients to speak their native language with an accent different from speakers belonging to the same language community: the patient lacks the ability to make the phonemic and phonetic contrasts of his/her native language and demonstrates suprasegmental alterations which cause listeners to perceive the accent as distinctly ‘foreign’. In 1982, Whitaker proposed 4 diagnostic criteria for FAS: 1) the accent is considered by the patient, acquaintances and investigators as foreign, 2) it is unlike the patient’s accent before the insult, 3) the accent is clearly related to central nervous system damage, 4) there is no evidence in the patient’s background of him/her being a speaker of a foreign language (pp. 197- 198). Although FAS of “acquired neurogenic origin” is the most common variant of the disorder, there exists a “developmental”, “psychogenic” and “mixed variant” as well (Verhoeven and Mariën, 2010).
In FAS of neurogenic origin the foreign accent is incited by a lesion affecting the central nervous system, often a stroke or brain trauma. However, FAS has also been attested in relation to MS (Villaverde-Gonzalez et al., 2003), tumor (Masao et al., 2011; Tomasino et al., 2013; Abel et al., 2009), as well as other pathologies affecting the CNS. Developmental FAS can be regarded as a subtype of neurogenic FAS; only here it is developmental in nature, affecting speech as it develops. In the psychogenic variant, a psychological/psychiatric disorder incites FAS, whereas the mixed variant is originally neurogenic in nature, but the accent change has such a profound effect on the patient’s psychological status that he/she internalizes it by further developing the accent in order ‘to create a more “believable” personality’ (Verhoeven and Mariën 2010, p. 600