Evidencing a place for the hippocampus within the core scene processing network

Functional neuroimaging studies have identified several core brain regions that are preferentially activated by scene stimuli, namely posterior parahippocampal gyrus (PHG), retrosplenial cortex (RSC), and transverse occipital sulcus (TOS). The hippocampus (HC), too, is thought to play a key role in scene processing, although no study has yet investigated scene-sensitivity in the HC relative to these other core regions. Here, we characterised the frequency and consistency of individual scene-preferential responses within these regions by analysing a large dataset (n=51) in which participants performed a one-back working memory task for scenes, objects, and scrambled objects. An unbiased approach was adopted by applying independently-defined anatomical ROIs to individual-level functional data across different voxel-wise thresholds and spatial filters. It was found that the majority of subjects had preferential scene clusters in PHG (max=100% of participants), RSC (max=76%), and TOS (max=94%). A comparable number of individuals also possessed significant scene-related clusters within their individually defined HC ROIs (max=88%), evidencing a HC contribution to scene processing. While probabilistic overlap maps of individual clusters showed that overlap peaks were close to those identified in group-level analyses (particularly for TOS and HC), inter-individual consistency varied across regions and statistical thresholds. The inter-regional and inter-individual variability revealed by these analyses has implications for how scene-sensitive cortex is localised and interrogated in functional neuroimaging studies, particularly in medial temporal lobe regions, such as the HC. Hum Brain Mapp 37:3779-3794, 2016. (c) 2016 Wiley Periodicals, Inc.