A single case study from Israel of a bilingual man who suffered damage to one part of his brain suggests that a person’s first and second language are represented in different parts of the brain.

Dr Raphiq Ibrahim of the Department of Learning Disabilities at the University of Haifa carried out the study and published a short paper on it in March 2009 in the journal Behavioral and Brain Functions. He also revealed a bit more about his work to the media yesterday, 8 July.

Research on where different languages sit in the brain is unclear, especially that which investigates languages of similar and different linguistic structures, said Ibrahim.

Some studies suggest that all the languages a person learns are represented in one area of the brain while others suggest that second and susequent languages are dissociated in the brain from the mother tongue.

While there are several ways to investigate this further, Ibrahim said the best way was to examine a bilingual person who has suffered brain damage.

His patient was a 41-year old bilingual man with Arabic as his mother tongue and fluent to a high level in Hebrew which he used in his professional life.

The patient had suffered brain damage as a result of hemorrhage related to herpes encephalitis that left him with language disorder or aphasia that was still present after rehabilitation.

During rehabilitation the man’s Arabic improved more than his Hebrew. After rehabilitation Ibrahim invited the patient to complete standardized language and cognitive tests that showed damage to his Hebrew skills was significantly greater than damage to his Arabic skills.

Ibrahim wrote that:

“The results revealed dissociation between the two languages in terms of both the types and the magnitude of errors, pointing to aphasic symptoms in both languages, with Hebrew being the more impaired.”

Further analysis also showed that the dissociation was caused by damage at the lexical level (vocabulary) rather than to the semantic system (meaning and interpretation).

Ibrahim’s paper concluded that:

“The results suggest that the principles governing the organization of lexical representations in the brain are not similar for the two languages.”

Ibrahim told the press that even though this is not enough evidence from which to develop a structural model of language representation in the brain, this finding is an important step because the two languages, which have similar structure, phonetics and syntax, have not been studied like this before.

“Most of the evidence in this field is derived from clinical observations of brain damage in English- and Indo-European-speaking patients, and few studies have been carried out on individuals who speak other languages, especially Semitic languages such as Hebrew and Arabic.” said Ibrahim.

“Selective deficit of second language: a case study of a brain-damaged Arabic-Hebrew bilingual patient.”
Ibrahim R.
Behavioral and Brain Functions 2009, 5:17.
Published online 12 March 2009.

Source: University of Haifa.

Written by: Catharine Paddock, PhD