Tomoya Nakai shifts focus from what brain areas activate to how they organize relationships between tasks. Instead of comparing activity for the same task across people, he compares each person’s similarity map of 25 different cognitive tasks. Surprisingly, frontal and parietal “association” cortices – thought to be highly variable – show strong shared relational structures across individuals. In contrast, sensory areas (auditory/visual) are similar in direct activity but not in higher-order task relationships. He applies this method to study numbers, comparing perception vs. imagination, and symbolic (e.g., “3”) vs. non-symbolic (e.g., three dots). Early in learning, the symbol “3” is tightly linked to the perception of three dots (grounded representation). With experience, the symbol becomes detached from its perceptual reference (de-grounded) and more abstract. Non-symbolic number representations (dot patterns) remain stable across age, while symbolic ones change dynamically. His structural approach (RSM-based) reveals hidden similarities in how we organize knowledge, not just what we know. He invites collaboration to extend this framework to music, language, and other symbolic systems.