A number of regions in the human brain are known to be involved in processing natural scenes, but the field has lacked a unifying framework for understanding how these different regions are organized and interact. We provide evidence from functional connectivity and meta-analyses for a new organizational principle, in which scene processing relies upon two distinct networks that split the classically defined Parahippocampal Place Area (PPA). The first network consists of the Occipital Place Area (OPA/TOS) and posterior PPA, which contain retinotopic maps and do not show strong memory or context effects. The second network consists of the caudal Inferior Parietal Lobule (cIPL), Retrosplenial Complex (RSC), and anterior PPA, which connect to the hippocampus and are involved in a much broader set of tasks involving episodic memory and navigation. We propose that these two distinct networks capture the primary functional division among scene processing regions, between those that process visual features from the current view of a scene and those that connect information from a current scene view with a much broader temporal and spatial context. This new framework for understanding the neural substrates of scene processing bridges results from many lines of research, and makes specific functional predictions.
Significance Statement: There are a number of brain regions that only show high levels of activity for full photographic scenes, not individual objects. By examining their relationships to each other and the rest of the brain, we argue that there are two types of scene processing regions that belong to two separate networks. One network, which overlaps which most of the visual system, processes visual features of the current view of the world, such as spatial layout. Another network, which is connected to long-term memory, puts this moment-by-moment information in context, allowing us to navigate through environments and remember past events in familiar locations. These two groups of brain regions cooperate to help us understand the world and our place in it.
Authors report no conflict of interest
Funding sources: Funding was provided by a National Science Foundation Graduate Research Fellowship (to CB) under grant number DGE-0645962, and Office of Naval Research Multidisciplinary University Research Initiative (to DMB and LF) grant number N000141410671.