Bimodal language switching: New insights from signing and typing

- Switching between speaking and signing leads to a reduction of switch costs.
- We assume less costly output channel inhibition instead of lexical inhibition.
- Output channel inhibition seems to be restricted to sign language.
- Bimodal switching between speaking and typing needs more costly lexical inhibition.

Language switching typically refers to unimodal switching between two spoken languages. In bimodal language switching, one language is produced vocally and the other language is produced manually (e.g., a sign language). We compared unimodal language switching with two different kinds of bimodal language switching for non-signers. In Experiment 1a and 1b participants switched between speaking and newly learned signs. Participants of Experiment 2 switched between two originally spoken languages in a bimodal way: One language was produced vocally and the other language was produced manually (by typing). Interestingly, switch costs were reduced for bimodal compared to unimodal switching in Experiment 1a and 1b but not in Experiment 2. This speaks for different language control mechanisms. We assume less costly output channel inhibition for switching between speaking and signing (Experiment 1a and 1b) and more costly lexical inhibition for switching between speaking and typing (Experiment 2).