Balancing bilinguals II: lexical comprehension and cognitive processing in children learning Spanish and English.

The present study investigated developmental changes in lexical comprehension skills in early sequential bilinguals, in both Spanish (L1) and English (L2), exploring the effects of age, years of experience, and basic-level cognitive processing (specifically the ability to maintain performance during mixed vs. single-language processing) within a timed picture-word verification task. Participants were 100 individuals, 20 at each of five different age levels (ages in years, 5-7, 8-10, 11-13, 14-16, and adults). All had learned Spanish as a first language in the home, with formal English experience beginning at 5 years. Gains (as indexed by increased response speed) were made in both languages across age, although these gains were greater in English than in Spanish. The youngest participants were relatively "balanced" in their crosslinguistic performance. By middle childhood, performance was better in English. There were no response decrements at any age between the mixed and single-language processing conditions. These results are compared to those from a previous study that investigated basic-level lexical production in developing Spanish-English bilinguals. Both studies show a move toward English dominance in middle childhood, but the transition occurs earlier in comprehension. The production study showed differences between mixed and single-language processing (reflecting potential interlanguage interference) that are not evident in comprehension.