Asymmetric activation of number codes in bilinguals: further evidence for the encoding complex model of number processing.

In two experiments, Filipino-English bilinguals were asked to verify simple addition equations that were presented either in digit, verbal-Filipino, or verbal-English formats and that included different types of sum probes. The main results show (1) faster and more accurate processing of digit and English items than of Filipino items, (2) stronger associative interference by type of probe with the digit and English items compared with the Filipino items, and (3) priming of responses from English to digit codes, and from Filipino to digit codes, but not vice versa. The results were explained by using an elaborated version of Campbell's (1994) encoding complex model with additional assumptions to address the experience of bilinguals. The additional assumptions relate to the preference among the bilingual's two verbal formats, the different strengths of activation pathways within each format, and the asymmetric activation across formats.