Neural connectivity changes related to vocabulary knowledge effects during second language comprehension

Vocabulary knowledge is a key factor of second language listening success. Our previous behavioral and electrophysiological studies showed faster processing for sentences containing vocabulary with productive knowledge, accompanied by changes in neural activity during sentence listening tasks. However, it is still unclear how vocabulary knowledge shapes functional connectivity across regions during online comprehension. To address this issue, we estimated phase-based connectivity using the weighted phase lag index, identified between level subnetworks with the Network-Based Statistic, and examined whether vocabulary-level effects emerge as changes in overall network strength, clustered organization, or bridging roles. Connectivity differences were most consistent for productive knowledge, appearing mainly as localized increases in bridging or intermediary roles rather than as broad increases in within-module hubness. However, none of these differences survived family-wise correction, and the findings are best treated as exploratory targets for confirmatory replication.