Joint-embeddings reveal functional differences in default-mode network architecture between marmosets and humans

The default-mode network (DMN) is a distributed functional brain system integral for social and higher-order cognition in humans with implications in a myriad of neuropsychological disorders. In this study, we compared the functional architecture of the DMN between humans and marmosets to assess their similarities and differences using joint gradients. This approach permits simultaneous large-scale mapping of functional systems across the cortex of humans and marmosets, revealing evidence of putative homologies between them. In doing so, we find that the DMN architecture of the marmoset exhibits differences along its anterolateral-posterior axis. Specifically, the anterolateral node of the DMN (dorsolateral prefrontal cortex) displayed weak connections and inconsistent connection topographies as compared to its posterior DMN-nodes (posterior cingulate and posterior parietal cor-tices). We also present evidence that the marmoset medial prefrontal cortex and temporal lobe areas correspond to other macroscopical distributed functional systems that are not part of the DMN. Given the importance of the marmoset as a pre-clinical primate model for higher-order cognitive functioning and the DMN's relevance to cog-nition, our results suggest that the marmoset may lack the capacity to integrate neural information to subserve cortical dynamics that are necessary for supporting diverse cognitive demands.

Automated summary

This study compared the functional architecture of the DMN between humans and marmosets and found similarities and differences between them. The marmoset's DMN exhibited differences along its anterolateral-posterior axis, with weak connections and inconsistent connection topographies in the anterolateral node compared to the posterior nodes. Additionally, the marmoset's medial prefrontal cortex and temporal lobe areas corresponded to other distributed functional systems, not part of the DMN.