Principles of bilingual aphasia assessment and interpretation of findings / Michel Paradis

Principles of bilingual aphasia assessment and interpretation of findings / Michel Paradis. In Perspectives neuropsycholinguistiques sur l'aphasie - NeuroPsychoLinguistic Perspectives on Aphasia,colloque international organisé par l'Unité de Recherche Interdisciplinaire Octogone de l'Université Toulouse II-Le Mirail (France). Toulouse,21-23 juin 2012.Assessment: Because patients may recover each of their languages to vastly different extents (parallel,differential,successive,selective,blending,(alternating) antagonistic recoveries and selective aphasia) (Paradis,2008),all languages previously spoken by the patient should be assessed. Not testing one of a patient's languages may have detrimental social and/or clinical consequences. It is therefore no longer ethically acceptable to assess aphasic patients on the basis of the examination of only one of their languages. However,the evaluation instrument should not be a mere translation of a battery designed for,and standardized in,another language,for a number of reasons: For instance,syntactic constructions,such as the passive in English,are rarely if ever used,or are much simpler,in some languages. Hence,most translations will not yield interpretable results. Corresponding items in another language must be selected so as to tap the same information as the original,in accordance with the rationale that motivated the construction of the items in the first place. The tests must be functionally equivalent and directly comparable,task by task,with respect to both degree of difficulty and nature of the material being tested,well beyond its cultural compatibility. This is why the Bilingual Aphasia Test was designed. Its various versions are culturally and linguistically equivalent and criteria of cross-language equivalence vary with each task (Paradis,2011). Interpretation of test results: It is important to realize that manifestations of aphasia symptoms differ across various languages in accordance with their specific structures. The reason why a certain type of error is more prevalent in one of a patient's languages may be due to one or more of several factors: The incidence of obligatory contexts,the frequency of use of a structure in a given language,the structural complexity of the item; the presence or absence of redundancy; whether nouns and verbs exist as bare roots or must necessarily be inflected; whether,when inflections are omitted the remaining form is pronounceable or not,and whether the form is memorized or derivable by rule ? namely,regular or irregular (Paradis,2001). The type of error depends on the type of aphasia,but potential errors in each case are constrained by the structural characteristics of each language. In addition,for a meaningful analysis that leads to effective rehabilitation,the age of appropriation,the degree of practice of L2,as well as the age at time of assessment in case of a late learned L2,must be taken into consideration. Depending on the age and manner of acquisition and the degree of use of a second language,its cerebral representation will depend on different cerebral mechanisms. Early acquired languages rely to a great extent on automatized implicit linguistic competence that is subserved by procedural memory whereas later learned languages rely to a greater extent on consciously controlled explicit metalinguistic knowledge that is subserved by declarative memory (Paradis,2008). As a result,double dissociations are observed in the better preservation of the first language (in amnesia and Alzheimer's disease) or of the second language (in aphasia,Parkinson's disease,and psychoses) These age factors may also affect the transfer of therapeutic benefits from a treated to a non-treated language.

Disciplines : Psycholinguistique,Troubles de la parole et du langage (troubles de la communication, de l'articulation ; orthophonie)
Mots-clés : langage et langues (compréhension),tests diagnostiques,multilinguisme,déficit cognitif,troubles du langage,aphasie
Type de document : image en mouvement
Type de ressource : lecture
Niveau : licence,master
Auteurs ou éditeurs : Bruno BASTARD,Université Toulouse II-Le Mirail,Université Toulouse II-Le Mirail SCPAM,Michel PARADIS