Parallel systems for social and spatial reasoning within the cortical apex

What is the cognitive and neural architecture for high-level reasoning? We hypothesize that systems for understanding people and places remain separate throughout the brain, but share a parallel organization. We test this hypothesis using deep neuroimaging of individual human brains on diverse tasks involving reasoning and memory about familiar people, places, and objects. We find that thinking about people and places elicits responses in distinct areas of high-level association cortex, spanning the frontal, parietal, and temporal lobes. Person- and place-preferring brain regions are systematically yoked across cortical zones. These areas have strongly domain-specific response profiles across visual, semantic, and episodic tasks, and are specifically functionally connected to other parts of association cortex with like category preference. Social and spatial networks are anatomically separated even at the top of the cortical hierarchy, and include parts of cortex with anatomical connections to the hippocampal formation. These results demonstrate parallel, domain-specific networks within the cortical apex. They suggest that domain-specific systems for reasoning constitute components of a broader cortico-hippocampal system for long-term memory.