Decreased inter-hemispheric connectivity predicts a coherent retrieval of auditory symbolic material in a laboratory model of cultural transmission

Investigating the transmission of information between individuals is essential to understand how human culture evolved. Coherent information transmission (i.e., transmission without significant modifications or loss of fidelity) helps preserving cultural traits and traditions over time, while innovation may lead to new cultural variants. Although much research has focused on the cognitive mechanisms underlying cultural transmission, little is known on the brain underpinnings of coherent transmission of information. To address this gap, we combined a laboratory model of cultural transmission, the signalling games, with structural (from high-resolution diffusion imaging) and functional connectivity (from resting-state functional magnetic resonance imaging [fMRI]). We found that individuals who exhibited more coherence in the transmission of the information were characterized by lower levels of both structural and functional inter-hemispheric connectivity. Specifically, higher coherence negatively correlated with the strength of bilateral structural connections between frontal and subcortical, insular and temporal brain regions. Similarly, we observed increased inter-hemispheric functional connectivity between inferior frontal brain regions derived from structural connectivity analysis in individuals who exhibited lower transmission coherence. Our results suggest that inter-hemispheric connections may bwe detrimental for preserving coherence in information transmission, while a certain degree of lateralization in the brain may be required.