An evolutionary gap in primate default mode network organization
Clément M. Garin, Yuki Hori, Stefan Everling, Christopher T. Whitlow, Finnegan J. Calabro, Beatríz Luna, Mathilda Froesel, Maëva Gacoin, Suliann Ben Hamed, Marc Dhénain, Christos Constantinidis
Abstract
The human default mode network (DMN) is engaged at rest and in cognitive states such as self-directed thoughts. Interconnected homologous cortical areas in primates constitute a network considered as the equivalent. Here, based on a cross-species comparison of the DMN between humans and non-hominoid primates (macaques, marmosets, and mouse lemurs), we report major dissimilarities in connectivity profiles. Most importantly, the medial prefrontal cortex (mPFC) of non-hominoid primates is poorly engaged with the posterior cingulate cortex (PCC), though strong correlated activity between the human PCC and the mPFC is a key feature of the human DMN. Instead, a fronto-temporal resting-state network involving the mPFC was detected consistently across non-hominoid primate species. These common functional features shared between non-hominoid primates but not with humans suggest a substantial gap in the organization of the primate's DMN and its associated cognitive functions.