The brain evolved as a sensory-motor machine that drives behavior while being linked to the world through sensors. Human cognition abstracts from these sensory-motor roots but retains intimate ties. The brain's structure reflects this history. How do neural processes at different distances from the sensory and motor surfaces integrate to achieve meaningful and grounded cognition? This is a challenge given the time-continuous and graded nature of sensory-motor processing, which enables continuous online updating. It is also a major challenge to understanding development and autonomous learning, in which the coupling across functional boundaries evolves under the influence of online activation patterns.