title: Activation of cerebellar hemispheres in spatial memorization of saccadic eye movements: an fMRI study.
abstract: What mechanisms allow us to direct a precise saccade to a remembered target position in space? The cerebellum has been proposed to be involved not only in motor and oculomotor control, but also in perceptual and cognitive functions. We used functional MRI (Echoplanar imaging at 1.5 T) to investigate the role of the cerebellum in the control of externally triggered and internally generated saccadic eye movements of high and low memory impact, in six healthy volunteers. Memory-guided saccades to remembered locations of 3 targets (triple-step saccades) in contrast to either central fixation or to visually guided saccades activated the cerebellar hemispheres predominantly within lobuli VI-crus I. The same areas were activated when an analogous visuospatial working memory task was contrasted to the triple-step saccades. Visually guided saccades activated the posterior vermis and the triple-step saccades, contrasted to the working memory task, activated predominantly the posterior vermis and paravermal regions. Our data confirm the primary involvement of the posterior vermis for visually-triggered saccadic eye movements and present novel evidence for a role of the cerebellar hemispheres in the mnemonic and visuospatial control of memory-guided saccades.
authors.affiliation: Department of Neurology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany. nitschke_m@neuro.mu-luebeck.de
authors.forename: Matthias F
authors.initials: MF
authors.lastname: Nitschke
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Binkofski
authors.forename: Giovanni
authors.initials: G
authors.lastname: Buccino
authors.forename: Stefan
authors.initials: S
authors.lastname: Posse
authors.forename: Christian
authors.initials: C
authors.lastname: Erdmann
authors.forename: Detlef
authors.initials: D
authors.lastname: Kömpf
authors.forename: Rüdiger J
authors.initials: RJ
authors.lastname: Seitz
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Heide
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002531:Cerebellum / Q000033:anatomy & histology* / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D010775:Photic Stimulation; D012438:Saccades / Q000502:physiology*