title: Connectivity architecture and subdivision of the human inferior parietal cortex revealed by diffusion MRI.
abstract: The human inferior parietal cortex convexity (IPCC) is an important association area, which integrates auditory, visual, and somatosensory information. However, the structural organization of the IPCC is a controversial issue. For example, cytoarchitectonic parcellations reported in the literature range from 2 to 7 areas. Moreover, anatomical descriptions of the human IPCC are often based on experiments in the macaque monkey. In this study, we used diffusion-weighted magnetic resonance imaging combined with probabilistic tractography to quantify the connectivity of the human IPCC, and used this information to parcellate this cortex area. This provides a new structural map of the human IPCC, comprising 3 subareas (inferior parietal cortex anterior, IPC middle, and IPC posterior) of comparable size, in a rostro-caudal arrangement in the left and right hemispheres. Each subarea is characterized by a connectivity fingerprint, and the parcellation is similar to the subdivision reported for the macaque IPCC with 3 areas in a rostro-caudal arrangement (PF, PFG, and PG). However, the present study also reliably demonstrates new structural features in the connectivity pattern of the human IPCC, which are not known to exist in the macaque. This study quantifies intersubject variability by providing a population representation of the subarea arrangement and demonstrates the substantial lateralization of the connectivity patterns of the IPCC.
authors.affiliation: Research Group "Cortical Networks and Cognitive Functions".
authors.forename: Michael
authors.initials: M
authors.lastname: Ruschel
authors.affiliation: Research Group "Cortical Networks and Cognitive Functions".
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Knösche
authors.affiliation: Department of Neuropsychology.
authors.forename: Angela D
authors.initials: AD
authors.lastname: Friederici
authors.affiliation: Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Turner
authors.affiliation: Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Geyer
authors.affiliation: Research Group "Cortical Networks and Cognitive Functions", Department of Neuropsychology.
authors.forename: Alfred
authors.initials: A
authors.lastname: Anwander
mesh_terms: D000328:Adult; D038524:Diffusion Magnetic Resonance Imaging; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009434:Neural Pathways / Q000033:anatomy & histology; D010296:Parietal Lobe / Q000033:anatomy & histology*
keywords: connectivity-based parcellation; diffusion MRI; diffusion tensor imaging; human parietal lobe; inferior parietal cortical convexity; probabilistic tractography