title: Dissociable cerebellar activity during spatial navigation and visual memory in bilateral vestibular failure.
abstract: OBJECTIVE
  Spatial orientation and navigation depends on information from the vestibular system. Previous work suggested impaired spatial navigation in patients with bilateral vestibular failure (BVF). The aim of this study was to investigate event-related brain activity by functional magnetic resonance imaging (fMRI) during spatial navigation and visual memory tasks in BVF patients.
  
  
  METHODS
  Twenty-three BVF patients and healthy age- and gender matched control subjects performed learning sessions of spatial navigation by watching short films taking them through various streets from a driver's perspective along a route to the Cathedral of Cologne using virtual reality videos (adopted and modified from Google Earth). In the scanner, participants were asked to respond to questions testing for visual memory or spatial navigation while they viewed short video clips. From a similar but not identical perspective depicted video frames of routes were displayed which they had previously seen or which were completely novel to them.
  
  
  RESULTS
  Compared with controls, posterior cerebellar activity in BVF patients was higher during spatial navigation than during visual memory tasks, in the absence of performance differences. This cerebellar activity correlated with disease duration.
  
  
  CONCLUSIONS
  Cerebellar activity during spatial navigation in BVF patients may reflect increased non-vestibular efforts to counteract the development of spatial navigation deficits in BVF. Conceivably, cerebellar activity indicates a change in navigational strategy of BVF patients, i.e. from a more allocentric, landmark or place-based strategy (hippocampus) to a more sequence-based strategy. This interpretation would be in accord with recent evidence for a cerebellar role in sequence-based navigation.
authors.affiliation: Dept. of Neurology, University of Lübeck and University Hospitals Schleswig-Holstein, Lübeck, Germany.
authors.forename: N M
authors.initials: NM
authors.lastname: Jandl
authors.affiliation: Dept. of Neurology, University of Lübeck and University Hospitals Schleswig-Holstein, Lübeck, Germany; Institute of Psychology II, University of Lübeck, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Sprenger
authors.affiliation: Dept. of Neurology, University of Lübeck and University Hospitals Schleswig-Holstein, Lübeck, Germany.
authors.forename: J F
authors.initials: JF
authors.lastname: Wojak
authors.affiliation: Dept. of Neurology, University of Lübeck and University Hospitals Schleswig-Holstein, Lübeck, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Göttlich
authors.affiliation: Dept. of Neurology, University of Lübeck and University Hospitals Schleswig-Holstein, Lübeck, Germany; Institute of Psychology II, University of Lübeck, Germany.
authors.forename: T F
authors.initials: TF
authors.lastname: Münte
authors.affiliation: Dept. of Neurology, University of Lübeck and University Hospitals Schleswig-Holstein, Lübeck, Germany; Institute of Psychology II, University of Lübeck, Germany.
authors.forename: U M
authors.initials: UM
authors.lastname: Krämer
authors.affiliation: Dept. of Neurology, University of Lübeck and University Hospitals Schleswig-Holstein, Lübeck, Germany. Electronic address: christoph.helmchen@neuro.uni-luebeck.de.
authors.forename: C
authors.initials: C
authors.lastname: Helmchen
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001931:Brain Mapping; D016022:Case-Control Studies; D002531:Cerebellum / Q000098:blood supply / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D011601:Psychophysics; D013028:Space Perception; D065854:Spatial Navigation / Q000502:physiology*; D015837:Vestibular Diseases / Q000473:pathology* / Q000503:physiopathology*; D058585:Vestibular Evoked Myogenic Potentials / Q000502:physiology
chemical_list: D010100:Oxygen
keywords: bilateral vestibular failure; cerebellum; navigation; visual memory