Is the digit effect a cognate effect? Digits (still) differ from pictures in non-phonologically mediated language switching

Language control in bilinguals is often investigated with the language switching paradigm. Switch costs reflect the ease/difficulty of applying this control mechanism. The type of stimuli employed in the experiments may influence switch costs. To date, only one study has compared digit vs picture processing, reporting reduced switch costs for digits (Declerck, Koch & Philipp, 2012). This result was adjudicated to phonological overlap between the languages used. Crucially, it remains an open question whether this digit effect generalises to language combinations without phonological relation. We fill this gap by investigating language switching with two language pairs differing in relative proficiency (L1 Chinese-L2 English, L1 Chinese-L3 French), where cross-language phonological activation is not expected. Overall, a digit effect is observed in the Chinese-English pair. Contrary to Declerck et al.'s (2012) finding, digits increased switch costs. Phonological mediation cannot explain this effect; instead, we suggest its origin lies in within-language word association links.