title: Functional Dissociations Within Posterior Parietal Cortex During Scene Integration and Viewpoint Changes.
abstract: The posterior parietal cortex (PPC) is an anatomically heterogeneous brain region implicated in a wide range of cognitive operations, including egocentric spatial processing and both short- and long-term memory. Here, we report functional specificities of cytoarchitectonically defined subregions of PPC during the processing of scenes across changes in viewpoint. Participants (n = 16) saw photographs of familiar and unfamiliar places while undergoing functional magnetic resonance imaging (fMRI). On each trial, 4 viewpoints of the same place were presented, with either a plausible sequence of viewpoints (SEQ) or a scrambled order (SCRA). Distinct response profiles were observed within PPC. Area 7A showed increased activity for SEQ versus SCRA order, regardless of place familiarity, whereas the rostral inferior parietal lobule showed preferential increases for unfamiliar versus familiar places in SEQ series. In contrast, more posterior subregions in both superior and inferior PPC exhibited increases for familiar versus unfamiliar places at the end of the sequence, regardless of order. The data highlight the distinctive contribution of several subregions of PPC during the processing of scenes, with specific cortical areas involved in the progressive integration of spatial information across viewpoint changes, and others involved in the retrieval and maintenance of scene information in memory.
authors.affiliation: University of Geneva, Geneva, Switzerland.|Department of Neurology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Mitsouko
authors.initials: M
authors.lastname: van Assche
authors.affiliation: University of Geneva, Geneva, Switzerland.|Department of Neurology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Valeria
authors.initials: V
authors.lastname: Kebets
authors.affiliation: University of Geneva, Geneva, Switzerland.|Department of Neurology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Patrik
authors.initials: P
authors.lastname: Vuilleumier
authors.affiliation: Department of Neurology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Assal
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010296:Parietal Lobe / Q000098:blood supply / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D021641:Recognition, Psychology / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D055815:Young Adult
keywords: egocentric processing; functional MRI; memory; prediction; scene perception