Changes in cerebellar activation pattern during two successive sequences of saccades.
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.
Stephan
Thomas
T
Center for Sensorimotor Research, Department of Neurology, Ludwig-Maximilians University, Munich, Germany. tstephan@nefo.med.uni-muenchen.de
Mascolo
Andrea
A
Yousry
Tarek A
TA
Bense
Sandra
S
Brandt
Thomas
T
Dieterich
Marianne
M
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*