Spontaneous inner speech in multilinguals: short-term and long-term effects on code-switching

We explored language switching (code-switching) in spontaneous inner speech in multilingual native Arabic speakers living in Israel. The aim of this study was to test the effects of both long-term variables (education and proficiency in Hebrew and English as non-native languages) and short-term variables (linguistic context and mood). We created a smartphone application which sent prompts twice a day to 49 female Arabic native speakers for 2 weeks. Participants also filled a questionnaire including questions about their linguistic background and use. Results show that the short-term variable linguistic context affected language use in inner speech: a more mixed linguistic context contributed to more code-switching. Mood however, did not affect code-switching. Hierarchical Regression showed that the long-term variables: education and proficiency in Hebrew, but not English, explained most of the variability in code-switching in inner speech. These findings are discussed in the context of language status in the minds of multilinguals, control and inhibition theories, and the characteristics of inner speech.