The second language interferes with picture naming in the first language: evidence for L2 activation during L1 production

Previous research has shown that when speakers produce words in their second language (L2), they also activate the phonological form of the translation of the word in their first language (L1). Here we investigated whether this holds in the opposite direction, i.e. when participants speak in exclusively in their L1. In a picture-word interference task, speakers named pictures in their L1 Dutch (“mes” [knife]) while ignoring L2 English auditory distractors phonologically related to the English translation of the target (“knight”) or unrelated (“plane”). Naming latencies were longer in the related compared to the unrelated condition, suggesting that the L2 translations were activated up to the phonological level. However, this pattern was only obtained when speakers were addressed in the target language (Dutch) throughout the experiment. Moreover, the size of this effect did not depend on individual L2 proficiency. We conclude that co-activation of two languages is not restricted to the dominant language.