We examined the role of general inhibitory control and general set
shifting processes in bilingual language production in 51 native Finnish
speakers with English as L2, mainly learnt after the age of 7. We
tested the hypothesis that inhibitory control, measured with the Simon
and Flanker tasks, is central when switching into L1 (Green, 1998)
and, more generally, that general set shifting processes, measured with
the Number-Letter task, underlie language switching and mixing (Meuter
& Allport, 1999).
The results were inconsistent. The basic language switch cost effects
were in line with the inhibitory control model, but the interactions
with the executive tasks did not support the model and were partly
contrary to it. The general set shifting hypothesis received some
support. Alternative explanations of the sources of the switching and
mixing cost asymmetries in bilingual language production are discussed.