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

Abstract 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.