A note on aphasia in bilingual patients: Pitres' and Ribot's laws.

Johann Gesner in 1770 probably provided the first description of dissociation in reading ability in different languages in a bilingual patient, who after brain damage was able to read Latin but not German. Clinical studies have since shown that bilingual 'aphasics' do not necessarily manifest the same language disorders with the same degree of severity in both languages. Superficially, different case findings indicate instances of shared and divergent representation of components of language in the bilingual brain. This paper considers a selection of many empirical studies, which have failed to reconcile the parallel recovery of language in many reported bilingual aphasiacs and the differential recovery in others. It reviews Pitres' rule (recovery of the most used acquired language) and Ribot's law (recovery of the native language) that are important concepts during recovery and rehabilitation of bilingual aphasiacs.