Salillas, E. 1 & Carreiras, M. 1, 2
1 Basque Center on Cognition, Brain and Language (BCBL). Donostia. Spain.
2 Ikerbasque. Basque Foundation for Science
There is a lively debate on the role of language in the development of mathematical concepts. The present study takes the chance of Spanish-Basque bilinguals´ different verbal structures for number words. In Spanish the decimal system is used for the verbal form of two digit numbers, while the twenty system is used in Basque (56 is “cincuenta y seis”= 50 and 6 in Spanish; and “berrogeita hamasei“ 40 and 16 in Basque). We studied the impact of this verbal code on the access to number semantics, that is, on the proposed innate analogue magnitude representation as reflected by the so called distance effect (Moyer and Landauer, 1967). ERPs were measured while balanced bilinguals performed a number comparison task between pairs of digits that entailed a Basque word relationship (BA pairs) versus numbers that entailed a Spanish word-decimal system relationship (SPABA pairs). We manipulated the distance between numbers (eg. close BA: 56-40 / far BA: 56-6). Crucially, we selected two groups of otherwise equally balanced bilinguals: 7 learned math in Spanish and 7 learned math in Basque. ERP results showed that the P2 distance effect was not present for BA pairs in the group who learned math in Spanish, regardless of their fluency in Basque. The fourth bin of delayed reaction times reflected this pair x distance x group interaction with an absence of the distance effect in the BA pair for the group that learned math in Spanish. This group, however, showed a later P3 distance effect. These results strongly suggest that the language of learning math is preferentially activated when using digits and that number semantics is permeable to language.