Human referential communication is often thought as coding– decoding a set of symbols, neglecting that establishing shared meanings requires a computational mechanism powerful enough to mutually negotiate them. Sharing the meaning of a novel sym- bol might rely on similar conceptual inferences across communica- tors or on statistical similarities in their sensorimotor behaviors. Using magnetoencephalography, we assess spectral, temporal, and spatial characteristics of neural activity evoked when people generate and understand novel shared symbols during live com- municative interactions. Solving those communicative problems induced comparable changes in the spectral profile of neural ac- tivity of both communicators and addressees. This shared neuro- nal up-regulation was spatially localized to the right temporal lobe and the ventromedial prefrontal cortex and emerged already be- fore the occurrence of a specific communicative problem. Commu- nicative innovation relies on neuronal computations that are shared across generating and understanding novel shared sym- bols, operating over temporal scales independent from transient sensorimotor behavior.