We first set out to investigate whether n-2 language repetition costs, which is a marker of persisting inhibitory control, could be observed during production and comprehension (Declerck & Philipp, 2017). The results indicate that persisting inhibition is implemented during bilingual production. However, this study also indicate that inhibitory control is possible, but not necessary, during bilingual comprehension. This was also further discussed in Declerck, Meade, and Grainger (2018) and will be further explored in Declerck and Philipp (in preparation).
Because of the sparse evidence for inhibitory control during comprehension in Declerck and Philipp (2017), we came up with a paradigm to further investigate this issue. The new bilingual flanker paradigm allows bilinguals to perform a classification task on a central word that was flanked by words from the same language or another language (for a closer look at a trial in this paradigm, see Figure 1). Two studies have been published showing that inhibitory control during comprehension can be observed with this paradigm (Declerck, Snell, & Grainger, 2018; Eben & Declerck, 2018). This paradigm was also presented at the 3th International Meeting of the Psychonomic Society (Amsterdam, Netherlands).
We further investigated how language control in more general terms would occur during comprehension. In two studies, covering eight experiments, we found no comprehension-based language-switch costs. Comprehension-based language-mixing costs were observed in one experiment, but none of the others, which also puts some doubt on whether language control is necessarily implemented during comprehension. One of these studies has been submitted for peer review (Declerck, Koch, Duñabeitia, Grainger, & Stephan, submitted) and was presented at the 20th ESCOP conference (Potsdam, Germany), while the other study is being written up (Mirault, Grainger, & Declerck, in preparation).
Next to persisting inhibition, we also set out to investigate whether inhibitory control is reactive. To this end, 24 French-Italian-English trilinguals practiced naming pictures in French or English prior to the n-2 language repetition block. The results indicated that more activated (i.e. practiced) languages are inhibited less.
We also performed several related studies, such as a meta-analysis on asymmetrical switch costs, which is the measure most often cited for bilingual inhibitory control. While it is very often used as a measure of inhibitory control, it is sometimes not observed. A preliminary analysis, on the other hand, shows that this is a very reliable effect. More specific analyses are run to confirm this finding and we project that this study will be written up by the end of 2018 (Gade, Declerck, Philipp, & Koch, in preparation) and will in turn be submitted for publication.
A second related study examined a controversial issue, namely whether bilingual inhibitory control experience enhances non-linguistic inhibitory control. To investigate this issue, we related bilingualism (language proficiency, age-of acquisition, and usage of both languages) to non-linguistic inhibition by presenting a battery of ten non-linguistic inhibition tasks (e.g. Simon task and Stroop task) to a group of 160 bilinguals. The results are still being analyzed (Gade & Declerck, in preparation).
We also examined whether language control would be similar to control processes implemented in a different linguistic context. To this end, we let French-English bilinguals perform a language switching task and contrasted this against a task in which they would switch between naming pictures with a formal name (e.g. boy) or an informal name (e.g. kid). The results indicated an overlap in control processes, but also differences. This study was presented at Psycholinguistics in Flanders (Ghent, Belgium), and will be submitted soon (Declerck, Ivanova, Grainger, & Duñabeitia, in preparation).
Finally, a workshop about bilingual inhibitory control was set up during this project at the Aix-Marseille University (18-09-2018). For this workshop, Andrea M. Philipp (RWTH Aachen, Germany) was invited to give a talk.
