Words Versus Pictures: Bilingual Performance on Verbal and Pictorial Measures of Executive Functions.

Purpose: This study examined bilinguals' performance on functional executive function map tasks such as the Zoo Map from the Behavioural Assessment of the Dysexecutive Syndrome and the extent to which working memory, set shifting, and inhibition measures predicted bilinguals' performance on these tasks. Additionally, we explored the utility of pictorial map tasks as a measure of complex executive function in bilinguals. We hypothesized that bilinguals would perform better on the pictorial map tasks due to the reduced language processing demand. Method: The analyses included 131 bilingual young adults who completed a comprehensive language history questionnaire, an English proficiency test, a battery of working memory and executive function tasks, and verbal and pictorial map tasks. Results: Contrary to predictions, bilinguals' performance on the verbal maps did not differ significantly from that on the pictorial maps. Two multiple regression models significantly predicted performance on the verbal and pictorial maps, accounting for 7%-25% of the variance in the map scores. Working memory and interference control were the most prominent predictors within these models. Conclusions: In our study, bilinguals' performance on the verbal maps did not differ significantly from that on the pictorial maps. Additionally, English proficiency did not correlate with the participants' verbal map scores. These results suggest that executive function map tasks (e.g., the Zoo Map) are a useful clinical tool for assessing executive function in bilinguals. The findings of this study are discussed in light of the current literature on executive functions in bilinguals.