Facilitation and Interference Effects During Cognate Retrieval in a Multilingual Person With Aphasia

Purpose: In this study, we investigated the phenomenon of cognate status– based picture-naming abilities before and after anomia treatment in a multilin gual person with poststroke aphasia whose languages vary in relation to lan guage typology, age of acquisition, proficiency, and exposure/use in the years leading up to the stroke. We examined baseline abilities as well as the efficacy of within-and cross-language generalization. Method: In a multiple-baseline study, we measured cognate versus noncognate picture-based naming in one multilingual person with mixed transcortical apha sia in three of his languages: Swahili, English, and Hebrew. We provided 18 hrs of word retrieval treatment in English and then retested his cognate versus non cognate retrieval in all three languages. Results: At baseline, no cognate advantage was observed in English (high pro ficiency, early acquisition, high daily use). A cognate advantage was observed for Hebrew (late acquisition, moderate proficiency, oft-used) and potentially for Swahili (high proficiency, early acquisition, rarely used). After treatment in English, our results indicated greater interference effects for cognates relative to noncognates in Hebrew and Swahili, but not English. Conclusions: Retrieval ability may be more influenced by prestroke usage than by age of acquisition or proficiency, with a facilitative cognate advantage for less proficient and/or less used languages. Furthermore, treating a stronger lan guage may result in interference of cognate retrieval more than noncognate retrieval in weaker languages. More studies are needed in this field to better understand the contribution of each factor and how we can manipulate them to our advantage in the aphasia clinic.