title: Dorso-medial and ventro-lateral functional specialization of the human retrosplenial complex in spatial updating and orienting.
abstract: The retrosplenial complex is a region within the posterior cingulate cortex implicated in spatial navigation. Here, we investigated the functional specialization of this large and anatomically heterogeneous region using fMRI and resting-state functional connectivity combined with a spatial task with distinct phases of spatial 'updating' (i.e., integrating and maintaining object locations in memory during spatial displacement) and 'orienting' (i.e., recalling unseen locations from current position in space). Both spatial 'updating' and 'orienting' produced bilateral activity in the retrosplenial complex, among other areas. However, spatial 'updating' produced slightly greater activity in ventro-lateral portions, of the retrosplenial complex, whereas spatial 'orienting' produced greater activity in a more dorsal and medial portion of it (both regions localized along the parieto-occipital fissure). At rest, both ventro-lateral and dorso-medial subregions of the retrosplenial complex were functionally connected to the hippocampus and parahippocampus, regions both involved in spatial orientation and navigation. However, the ventro-lateral subregion of the retrosplenial complex displayed more positive functional connectivity with ventral occipital and temporal object recognition regions, whereas the dorso-medial subregion activity was more correlated to dorsal activity and frontal activity, as well as negatively correlated with more ventral parietal structures. These findings provide evidence for a dorso-medial to ventro-lateral functional specialization within the human retrosplenial complex that may shed more light on the complex neural mechanisms underlying spatial orientation and navigation in humans.
authors.affiliation: NeuroLab, Department of Psychology, Hotchkiss Brain Institute, and Alberta Children's Hospital Research Institute, University of Calgary, A062, 2500 University Drive, NW, Calgary, AB, Canada. cfburles@ucalgary.ca.
authors.forename: Ford
authors.identifier: 0000-0002-4833-6318
authors.initials: F
authors.lastname: Burles
authors.affiliation: NeuroLab, Department of Psychology, Hotchkiss Brain Institute, and Alberta Children's Hospital Research Institute, University of Calgary, A062, 2500 University Drive, NW, Calgary, AB, Canada.
authors.forename: Edward
authors.initials: E
authors.lastname: Slone
authors.affiliation: NeuroLab, Department of Psychology, Hotchkiss Brain Institute, and Alberta Children's Hospital Research Institute, University of Calgary, A062, 2500 University Drive, NW, Calgary, AB, Canada.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Iaria
mesh_terms: D000328:Adult; D001931:Brain Mapping; D005260:Female; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009949:Orientation / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D013037:Spatial Behavior / Q000502:physiology*; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Functional connectivity; Navigation; Posterior cingulate; Spatial memory; fMRI