Shared or separate: control processes of cross- and within-language interference

Language control is an essential cognitive process that allows bilinguals to fluently produce language by reducing cross-language interference. Yet, it remains unclear whether the control processes implemented when reducing cross-language interference are similar to those when reducing within-language interference. Since prior research has shown contradictory results, we set out to investigate this issue further based on a combination of language switch costs, as a measure of control processes resolving cross-language interference, and Stroop incongruency, as a measure of control processes resolving within-language interference. Relying on a range of statistical techniques, the results across three experiments testing three different groups of bilinguals (i.e., Dutch-English, Arabic-English, and Chinese-English) showed no clear interaction between language switch costs and Stroop incongruency, and neither was this pattern influenced by language dominance. These results are more in line with the claim that different control processes are implemented to reduce cross- and within-language interference.