Functional roles of cortico-cortical and cortico-thalamo-cortical long-range connections

Determine the computational functions and mechanistic roles of long-range cortico-cortical connections and cortico-thalamo-cortical connections in the neocortex, including how these pathways originate, terminate, and influence information processing across cortical regions and the thalamus.

Background

The paper distinguishes two major classes of long-range pathways in the neocortex: cortico-cortical (CC) connections linking different cortical regions and cortico-thalamo-cortical (CTC) connections that route cortical signals through the thalamus back to cortex.

Despite extensive anatomical and physiological studies, the authors note that a comprehensive, unified understanding of the purposes and mechanisms of these long-range pathways is lacking. They frame their Thousand Brains Theory as an attempt to offer an integrative account, while explicitly acknowledging that the roles of CC and CTC connections remain insufficiently understood.