title: Looking for the compass in a case of developmental topographical disorientation: a behavioral and neuroimaging study.
abstract: Developmental topographical disorientation (DTD) is the presence of navigational deficits in the context of normal intellectual ability and in the absence of any perinatal, neurological, or psychiatric disorder. As only three cases of DTD have been fully described thus far, we are still unable to draw definitive conclusions about its nature and relationship with other visuospatial competencies, such as mental rotation. The case of Mr. L.A., a 38-year-old man with no history of neurological or psychiatric disorders, sheds some light on these open questions. A neuropsychological assessment including IQ, memory, visuospatial, visuoconstructive, and navigational tests showed that Mr. L.A. has pure navigational deficits affecting both route knowledge and cognitive map processing. Unlike previously described cases of DTD, Mr. L.A. was not affected by any other visuospatial or visuoconstructive deficits. In a functional magnetic resonance imaging (fMRI) task involving the recall of route knowledge, Mr. L.A. showed activation in the occipital areas, involved in low-level perceptual analysis of the stimuli, and showed no activation in the areas activated in controls with regard to route knowledge. The present case suggests that different types of DTD exist, which are characterized by different navigational difficulties and anomalous/lacking functional brain activities in specific navigational networks.
authors.affiliation: a Department of Psychology , "Sapienza" University of Rome , Rome , Italy.
authors.forename: Liana
authors.initials: L
authors.lastname: Palermo
authors.forename: Laura
authors.initials: L
authors.lastname: Piccardi
authors.forename: Filippo
authors.initials: F
authors.lastname: Bianchini
authors.forename: Federico
authors.initials: F
authors.lastname: Nemmi
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Giorgio
authors.forename: Chiara
authors.initials: C
authors.lastname: Incoccia
authors.forename: Umberto
authors.initials: U
authors.lastname: Sabatini
authors.forename: Cecilia
authors.initials: C
authors.lastname: Guariglia
mesh_terms: D000328:Adult; D000377:Agnosia / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology*; D059907:Functional Neuroimaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D009949:Orientation / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D013037:Spatial Behavior / Q000502:physiology*; D065855:Spatial Processing / Q000502:physiology*
keywords: Cognitive map; Developmental disorders; Functional magnetic resonance imaging; Human navigation; Mental rotation; Spatial memory; Topographical disorientation