Multi-area functional modules mediate feedforward and recurrent processing in visual cortical hierarchy

The visual cortex is organized hierarchically, but extensive recurrent pathways make it challenging to decipher the flow of information with single neuron resolution. Here, we characterize spiking interactions in populations of neurons from six interconnected areas along the visual hierarchy in awake mice. We generated multi-area, directed graphs of neuronal communication and uncovered two spatially-distributed functional modules. One module is positioned to transmit feedforward sensory signals along the hierarchy, while the other receives convergent input and engages in recurrent processing. The modules differ in layer and area distributions, convergence and divergence, and population-level temporal dynamics. These results reveal a neuronal-resolution cortical network topology in which distinct processing modules are interlaced across multiple areas of the cortical hierarchy.