Disrupting the semantic network shifts activity to domain-general brain regions

Semantic processing relies on flexible interactions between specialized lexico-semantic regions and domain-general control networks, particularly under challenging conditions. Using transcranial magnetic stimulation interleaved with functional magnetic resonance imaging, we investigated acute network adaptation when the left posterior middle temporal gyrus-a core lexico-semantic region-was perturbed during lexico-semantic decisions in 25 healthy participants. High-intensity transcranial magnetic stimulation over the posterior middle temporal gyrus induced task-specific activity increases across semantic control and lexical retrieval areas, as well as remote domain-general regions. Critically, increased local activity at the stimulation site correlated with slower reaction times, whereas greater upregulation in domain-general frontal regions was associated with less disrupted semantic performance. These findings indicate that acute semantic disruption triggers immediate, flexible recruitment of domain-general control areas consistent with the maintenance of task performance, highlighting the brain's capacity to dynamically adapt to interference. Our findings contribute to the current understanding of putative compensatory network-level mechanisms supporting lexico-semantic cognition.