In this talk I will focus on the issue of interaction at the semantic cognition level. My starting point is that the way in which we divide things into "kinds", or categorize our knowledge of the world emerges from experience and is shaped by language during development. Categories respond to an objective reality but are language-specific. In the case of cross-linguistic comparisons, this leads to asymmetries in the relation between words in the two languages and their referents: concepts can be encoded into a single label in one language but into multiple ones in another (e.g.: dedos in Spanish vs. fingers, toes in English). What happens then when a person grows up immersed in two languages that have different, competing ways of organizing the semantic space? Under which circumstances is there convergence or separation of the semantic organizational systems of the two languages?
I will present data from a speeded forced-choice picture selection task in which half the items were "wider" in one language and vice versa; in the example above, the category dedos is wider in Spanish than fingers is in English because dedos includes more concepts (appendages in all four extremities versus just to two upper ones). Conversely, brush in English is wider than brocha and cepillo in Spanish. Half the participants were tested entirely in English and half entirely in Spanish. The key question is: under which conditions bilingual participants, when placed under time pressure, over-extend or under-extend membership in a category in the test language according to the semantic organization of their other language.