Poster B57, Thursday, August 16, 3:05 – 4:50 pm, Room 2000AB

Is semantic processing language-dependent? Evidence from bilingual aphasia

Marco Calabria1, Nicholas Grunden1,2, Mariona Serra1, Carmen García Sánchez2, Albert Costa1,3;1Center for Brain and Cognition, Pompeu Fabra University, Barcelona, Spain, 2Hospital de la Santa Creu i Sant Pau, Barcelona, Spain, 3Institució Catalana de Recerca i Estudis Avançats (ICREA), Spain

Introduction. Individuals with aphasia frequently show lexical retrieval deficits due to increased interference amongst competitors during word selection. This has been demonstrated in tasks where this competition originates at a semantic level, such as naming pictures grouped by semantic category. These deficits are explained in terms of impaired semantic control, a set of abilities to some extent dependent on executive control. To what extent these abilities can be affected in a second language (L2) has not been extensively explored and findings in healthy individuals are not conclusive about the extent to which semantic processing is shared between languages. In this study we explore the effect of brain damage on semantic processing by comparing the performance of bilingual individuals with aphasia in tasks tapping semantic control in word production and comprehension. Methods. We investigate the naming performance of bilinguals with fluent aphasia and age-matched healthy controls in a semantically blocked cyclic naming task for the two languages (Catalan and Spanish). This task allows to measure the semantic interference as a difference in naming latencies between pictures grouped by the same semantic category or different categories. Also, we explore whether lexical deficits extend to comprehension by testing participants in a word-picture matching task during a mixed language condition. All the participants were early bilinguals and high proficient in Catalan and Spanish with a balanced use of the two languages. Results. In the semantically blocked cyclic naming task, the semantic interference effect was similar in bilingual patients with aphasia and healthy controls when required to perform the task in their first language (L1). However, bilingual patients showed a larger semantic interference effect than controls when naming stimuli in their L2. Similarly, in the word-picture matching task, patients suffered larger switch costs when required to switch from L1 into L2 than vice versa as compared to healthy controls. Conclusions. Taken together, these results suggest that lexical retrieval may be selectively impaired in bilinguals during those conditions in which semantic competition is higher as L2, possibly explained by an excessive inhibition. Moreover, these lexical deficits extent to those conditions when words are not intentionally retrieved for production and both languages are involved.

Topic Area: Multilingualism