title: Changes in cerebellar activation pattern during two successive sequences of saccades.
abstract: The changes in the cerebellar activation pattern of two successive fMRI scanning runs were determined for visually guided to-and-fro saccades in 12 healthy volunteers familiar with the study paradigm. Group and single subject-analyses revealed a constant activation of the paramedian cerebellar vermis (uvula, tonsils, tuber, folium/declive), which reflects constant ocular motor activity in both runs. A significant decrease in activation of the cerebellar hemispheres found in the second run is best explained by either a decrease in attention or the effects of motor optimization and learning. The significant, systematic changes of the cerebellar activation pattern in two successive runs were not expected, because the ocular motor task was simple, familiar, and highly automated. These findings indicate that similar effects may bias other cerebellar activation studies, in which sensorimotor tasks are repeated in a single session.
authors.affiliation: Center for Sensorimotor Research, Department of Neurology, Ludwig-Maximilians University, Munich, Germany. tstephan@nefo.med.uni-muenchen.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Stephan
authors.forename: Andrea
authors.initials: A
authors.lastname: Mascolo
authors.forename: Tarek A
authors.initials: TA
authors.lastname: Yousry
authors.forename: Sandra
authors.initials: S
authors.lastname: Bense
authors.forename: Thomas
authors.initials: T
authors.lastname: Brandt
authors.forename: Marianne
authors.initials: M
authors.lastname: Dieterich
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000328:Adult; D001931:Brain Mapping; D002525:Cerebellar Cortex / Q000033:anatomy & histology* / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012438:Saccades / Q000502:physiology*