Information Exchange between Cortical Areas: The Visual System as a Model.

This article reviews the mechanisms and principles underlying interareal information exchange in the brain, with a particular focus on the visual system. It discusses how structural connectivity, including short-range local connections and long-range rich-club hubs, forms the anatomical basis for communication between cortical areas. Using the visual system as a model, the review details feedforward, feedback, and transthalamic pathways—especially involving the pulvinar nucleus—and their roles in processing and integrating visual information. It further examines proposed neural communication mechanisms such as neural oscillations (including communication through coherence and nested oscillations), spiking synchrony, and the concept of communication subspaces that selectively transmit information between areas. The article concludes by highlighting open questions about how these mechanisms operate across multiple target areas and the need for advanced techniques to study interareal communication at the single-neuron level.