Figure 1, Key Figure. The three scene systems (a la Marr’s levels of analysis) and their development.

For example, the “scene categorization” system (including PPA) supports our ability to recognize the kind of place we are in (e.g., a city versus a beach), not a specific place, and is not involved in navigation. Accordingly, it does not represent information critical for navigation: sense (left/right), egocentric distance (near/far), first-person perspective (FPP) motion, location, or heading direction. Instead, it represents two kinds of information critical for categorizing scenes: i) spatial layout or “wholes” (i.e., the spatial arrangement of the major surfaces that make up the overall shape of a scene, and ii) scene content (e.g., the particular objects and textures that fill that space). By contrast, the “visually-guided” and “map-based” navigation systems (including OPA and RSC, respectively) do represent information essential for navigation. However, they do so differently, with the visually-guided navigation system representing information critical to guiding navigation through the immediately visible environment (i.e., sense, egocentric distance, FPP motion, and the local “parts” of a scene that constitute boundaries or obstacles), and the map-based navigation system representing information critical to guiding navigation from a specific place to some distant, out-of-sight place (i.e., sense, egocentric distance, location, heading direction, and the overall shape of a scene). Each system is further dissociated based on visual field bias, memory requirements, and the automaticity of the process they support. Finally, consistent with the distinct computational goals, representations, and cortical regions across the three scene systems, each is further hypothesized to develop along a different timeline. In particular, the scene categorization system is hypothesized to develop earlier than both the visually-guided navigation and map-based navigation systems.