The neural correlates of mid- and end-clause silent pauses in L1 and L2 speech

Abstract This study examined how the location of silent pausing (mid- vs. end-clause) may relate to neural processes during spontaneous L1 and L2 speech production. Twenty intermediate-level Japanese speakers of L2 English carried out eight monologic, oral decision-making tasks, four in English and four in Japanese. While completing the tasks, their brain activity was recorded through fMRI scanning. Participants’ speech was transcribed, and the resulting transcripts were annotated for mid- and end-clause silent pauses. Then, for the pauses identified, we conducted whole-brain analyses to identify relevant activation patterns, followed by region-of-interest analyses in language-related areas. We found that mid-clause pauses were linked to increased activation in language-related brain regions, with stronger effects for L2 speech. We also observed heightened activity in conceptualisation-related brain areas at end-clause positions in both L1 and L2 speech. In L2 English, participants also displayed greater activation in a concept-retrieval-related brain region in end-clause than in mid-clause position.