By Xiao-Jing Wang, NYU and NYU Shanghai

Decision-making, working memory and other cognitive functions involve many brain regions that interact through feedback loops. To investigate cortical inter-areal networks, we have developed a large-scale model of macaque cortex base on recently published directed and weighted connectivity data. We found that, by taking into account quantitative heterogeneity across cortical areas, this large network naturally displays a hierarchy of timescales: early sensory areas respond rapidly to an external input and the response decays away immediately after stimulus offset (appropriate for sensory processing), whereas association areas higher in the brain hierarchy are capable of integrating inputs over a long time and exhibit persistent activity (suitable for decision-making and working memory). Slower prefrontal and temporal areas have a disproportionate impact on global brain dynamics measured by functional connectivity. The model offers a new platform for investigating dynamics and functions of the large-scale primate brain.