Синдром иностранного акцента: причины, симптомы и механизмы развития.

Foreign accent syndrome is a rare medical condition in which patients develop speech patterns that are perceived as a foreign accent that is different from their native accent, without having acquired it in the perceived accent's place of origin. Foreign accent syndrome usually results from a stroke, or developmental problems. The condition might occur due to lesions in the speech production network of the brain, or may also be considered a neuropsychiatric condition. The condition was first reported in 1907, and between 1941 and 2009 there were 62 recorded cases. More recently, there is mounting evidence that the cerebellum, which controls motor function, may be crucially involved in some cases of foreign accent syndrome, reinforcing the notion that speech pattern alteration is mechanical and thus non specific. Generally, FAS is not a persisting disorder; it is a temporary stage in recovery from stroke or trauma or potentially a stage of deterioration. FAS mainly affects speech at a segmental or prosodic level. Vowels are more likely to be affected than consonants. Vowel errors include an increase in vowel tensing, monophthongization of diphthongs, and vowel fronting and raising. There is evidence of both vowel shortening and lengthening. Consonantal anomalies include cases of changes in articulation, manner, and voicing. On a suprasegmental level, there are changes in intonation and pitch, such as monotonous intonation or exaggerations in pitch height and range. There are also difficulties in using stress accents to indicate pragmatics and meaning. There is a tendency for FAS patients to switch to syllable timed prosody when their native language is stress timed. This perception could be due to changes in syllable durations, and the addition of epenthetic vowels.

Foreign accent syndrome is more commonly pronounced in females than it is in males. In a meta analysis of 112 patients with FAS, 97% were adults, and 67% were female. The typical age range for this disease is around 25–49 years of age. Only in 12.5% of the cases did the patients have previous exposure to the accent that they later seemed to develop due to FAS. The majority of FAS patients develop FAS due to a stroke, but it can also develop as a result of developmental or psychological disorders, trauma, or tumors. Of the patients with neurological damage, the majority had a lesion in the supratentorial left hemisphere. Lesions primarily affected the: premotor cortex, motor cortex, basal ganglia or Broca's area. Lesions are also seen in the cerebellum, which projects to the previous areas. Right hemisphere damage rarely causes FAS. The majority of patients with FAS usually present other speech disorders, such as: mutism, aphasia, dysarthria, agrammatism and apraxia of speech. first coined the term Foreign Accent Syndrome in 1982. He originally proposed some criteria that must be present in order to diagnose someone with FAS; they must be monolingual, they must have damage to their central nervous system that affects their speech, and their speech must be perceived as subjectively sounding foreign by themselves or clinicians. One problem with Whitaker's criteria is that they are based primarily on subjectivity, and therefore acoustic phonetic measurements are rarely used to diagnose FAS. In 2010, linguist Jo Verhoeven and neurolinguist Peter Mariën identified several subtypes of Foreign Accent Syndrome. They described a neurogenic, developmental, psychogenic and mixed variant. Neurogenic FAS is the term used when FAS occurs after central nervous system damage. Psychogenic FAS is used when FAS is psychologically induced, associated with psychiatric disorder or clear psychiatric traits. The term mixed FAS is used when patients develop the disorder after neurological damage, but the accent change has such a profound impact on the self perception and identity that they will modify or enhance the accent to make it fit with the new persona. Diagnosis, up until today, is generally purely perceptually based. However, in order to find out what subtype the patient has, complementary investigations are necessary. This differentiation is necessary for the clinician to allow for correct therapeutic guidance. Psychological evaluations may be performed in order to rule out any psychiatric condition that may be causing the change in speech, as well as tests to assess reading, writing, and language comprehension in order to identify comorbid disorders. Other well known cases of the syndrome include one that occurred in Norway in 1941 after a young woman, Astrid L., suffered a head injury from shrapnel during an air raid. After apparently recovering from the injury, she was left with what sounded like a strong German accent and was shunned by her fellow Norwegians.

Cases of foreign accent syndrome often receive significant media coverage, and cases have been reported in the popular media as resulting from various causes including stroke, allergic reaction, physical injury, and migraine. A woman with foreign accent syndrome was featured on both Inside Edition and Discovery Health Channel's Mystery ER in October 2008, and in September 2013 the BBC published an hour long documentary about Sarah Colwill, a woman from Devon, whose "Chinese" foreign accent syndrome resulted from a severe migraine. In 2016, a Texas woman, Lisa Alamia, was diagnosed with Foreign Accent Syndrome when, following a jaw surgery, she developed what sounded like a British accent. Ellen Spencer, a woman from Indiana who has foreign accent syndrome, was interviewed on the American public radio show Snap Judgment. The British singer George Michael reported briefly speaking in a West Country accent following his recovery from a three week long coma in 2012.

FAS is a very rare disorder. Likewise, there are not very many proposed treatments. Two that may provide relief to patients with FAS in the future include mastery of musical skills and “tongue reading”. In terms of mastery of music skills, research by Christiner and Reiterer suggests that musicians, both instrumental and vocal, are better at imitating foreign accents than non musicians. Vocalists are further better than instrumentalists at this task. In this way, individuals with FAS might be able to reimitate their original, lost native accents more easily if they master a musical especially vocal – skill. Pursuing this further, another set of researchers, Banks et al. investigated the role of hearing a foreign accent versus hearing and seeing someone use a foreign accent and which of these may be better for helping an individual replicate a foreign accent. Contrary to the researcher's predictions, “no differences were found in perceptual gains between the two modalities.” By contrast, a method that did seem to improve learning of non native speech sounds was “real time visual feedback of tongue movements with an interactive 3D visualization system based on electromagnetic articulography.”