In an earlier post, I described the case of a multilingual man who had a stroke and who, upon recovery, could no longer communicate with his wife in the language they had spoken together for some twenty years (see here). He suffered from multilingual aphasia, a condition that is the topic of this post.
Researchers are increasingly interested in the bilingual brain. Recent imaging techniques have greatly facilitated their work and the field of cognitive neuroscience of bilingualism is very active. An older branch of the field studies multilingual aphasic patients, that is those bilinguals or multilinguals who suffer language and speech impairment due to brain damage.
There are an increasing number of case studies published on the subject and as CUNY Graduate Center specialists Loraine K. Obler and Youngmi Park write, the impairment patterns generally found is that there is the same kind of aphasia in all of the person's languages. In addition, the degree of impairment is proportional to the proficiency level the patient had in each language prior to the incident.
Most aphasic patients show parallel recovery of their languages, that is the progress they make, albeit sometimes rather slow, is the same in all of their languages. There are, however, some 200 or so published cases today of differential impairment and recovery. McGill University linguist, Michel Paradis, organized them into a number of categories. One of the most frequent is selective recovery during which the patient never regains one or more languages. For example, a professor of physics whose mother tongue was Swiss German and whose second language was German moved to the French speaking part of Switzerland when he was thirty. From then on, French became his most used language. At age forty-four, he had a stroke and the first language to reappear was French. However, his mother tongue, Swiss German, never returned unfortunately.
In another type of recovery, differential recovery, the languages are differently impaired at the time of injury and are restored at the same or different rates. Here is an example: a Pole who spoke Polish (his mother tongue) as well as German and Russian was hit by a piece of shrapnel during the war. When he came to, his Russian was least impaired, his Polish was impaired in production, and his German was the most impaired. During recovery, he made most progress in Russian due to the Russian surroundings he lived in as well as the therapy he received in Russian.
Successive restitution, another recovery pattern, occurs when one language does not begin to reappear until another has been restored. A Swiss German mechanic had a motorbike accident and became aphasic. When language production was restored, he could speak only German (his second language after Swiss German). He made progress in the language due to therapy in that language. It is only when German was almost completely restored that he started to speak his first language, Swiss German.
Another pattern of recovery is the object of an earlier post. It has been termed antagonistic: one language regresses as the other progresses (see here). In the case described, French was the first language recovered; then as German and Swiss German progressed, French started losing ground. Even more spectacular is alternate antagonism which corresponds to a "come and go" pattern of recovery. Michel Paradis reported on a case of a nun in Morocco, who had a moped accident and became totally aphasic. She went through stages of recovery where she spoke one language quite well but the other was dysfluent, and then, a few weeks later (sometimes even a few days later), the reverse would be true—the fluent language became dysfluent and vice-versa.
Researchers who have examined these and other non-parallel recovery patterns, have attempted to account for the factors that explain the order in which the languages are recovered, in particular the first one. Here are a few that have been proposed over the years: the earliest language learned, the language most used just before the injury, the patient's affective and emotional state just prior to and after the injury (see Minkowski's explanation of the case described in my earlier post), the language used in therapy following the injury, the language that the person also writes and reads in, etc. not to forget the age of the patient and the severity of the injury.
It is probably a combination of several of these factors that can explain the non-parallel recovery of languages. All this becomes even more complex when patients show a different type of aphasia in each of their languages.
One final point pertains to the languages that are not recovered. Most researchers seem to agree that they are not lost but that they are inhibited, or more precisely that the control mechanisms that allow for language choice inhibit a language. The evidence for inhibition rather than loss comes from aphasic patients who may still understand a language but may no longer be able to speak it, from the cases of alternate antagonism where languages come and go over short periods of time, and from the many instances of multilingual aphasia where all the languages are finally recovered.
Templates courtesy of Presentation Magazine.
Martin R. Gitterman, Miral Goral & Loraine K. Obler (2012; eds.). Aspects of Multilingual Aphasia. Bristol / Buffalo / Toronto: Multilingual Matters.
"Life as a bilingual" posts by content area.
François Grosjean's website.