title: A Neural Basis for Developmental Topographic Disorientation.
abstract: Developmental topographic disorientation (DTD) is a life-long condition in which affected individuals are severely impaired in navigating around their environment. Individuals with DTD have no apparent structural brain damage on conventional imaging and the neural mechanisms underlying DTD are currently unknown. Using functional and diffusion tensor imaging, we present a comprehensive neuroimaging study of an individual, J.N., with well defined DTD. J.N. has intact scene-selective responses in the parahippocampal place area (PPA), transverse occipital sulcus, and retrosplenial cortex (RSC), key regions associated with scene perception and navigation. However, detailed fMRI studies probing selective tuning properties of these regions, as well as functional connectivity, suggest that J.N.'s RSC has an atypical response profile and an atypical functional coupling to PPA compared with human controls. This deviant functional profile of RSC is not due to compromised structural connectivity. This comprehensive examination suggests that the RSC may play a key role in navigation-related processing and that an alteration of the RSC's functional properties may serve as the neural basis for DTD.
  
  
  CONCLUSIONS
  Individuals with developmental topographic disorientation (DTD) have a life-long impairment in spatial navigation in the absence of brain damage, neurological conditions, or basic perceptual or memory deficits. Although progress has been made in identifying brain regions that subserve normal navigation, the neural basis of DTD is unknown. Using functional and structural neuroimaging and detailed statistical analyses, we investigated the brain regions typically involved in navigation and scene processing in a representative DTD individual, J.N. Although scene-selective regions were identified, closer scrutiny indicated that these areas, specifically the retrosplenial cortex (RSC), were functionally disrupted in J.N. This comprehensive examination of a representative DTD individual provides insight into the neural basis of DTD and the role of the RSC in navigation-related processing.
authors.affiliation: Princeton Neuroscience Institute and jiyekim@princeton.edu.
authors.forename: Jiye G
authors.initials: JG
authors.lastname: Kim
authors.affiliation: Center for the Neural Basis of Cognition and Department of Psychology, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213.
authors.forename: Elissa M
authors.initials: EM
authors.lastname: Aminoff
authors.affiliation: Princeton Neuroscience Institute and Department of Psychology, Princeton University, Princeton, New Jersey 08644, and.
authors.forename: Sabine
authors.initials: S
authors.lastname: Kastner
authors.affiliation: Center for the Neural Basis of Cognition and Department of Psychology, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213.
authors.forename: Marlene
authors.identifier: http://orcid.org/0000-0002-3814-1015
authors.initials: M
authors.lastname: Behrmann
mesh_terms: D000377:Agnosia / Q000473:pathology / Q000503:physiopathology*; D001931:Brain Mapping; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D065726:Limbic Lobe / Q000473:pathology / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009778:Occipital Lobe / Q000473:pathology / Q000503:physiopathology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D013028:Space Perception / Q000502:physiology; D065854:Spatial Navigation / Q000502:physiology*; D065855:Spatial Processing / Q000502:physiology*
keywords: developmental topographic disorientation; navigation; parahippocampal place area; retrosplenial cortex; scene perception; transverse occipital sulcus