Learning and performance on a ballistic task were investigated in
children with spina bifida meningomyelocele (SBM), with either upper level
spinal lesions (n = 21) or lower level spinal lesions (n
= 81), and in typically developing controls (n = 35).
Participants completed three phases (20 trials each) of an elbow
goniometer task that required a ballistic arm movement to move a cursor to
one of two target positions on a screen, including (1) an initial
learning phase, (2) an adaptation phase with a gain
change such that recalibration of the ballistic arm movement was required,
and (3) a learning reactivation phase under the original gain
condition. Initial error rate, asymptotic error rate, and learning rate
did not differ significantly between the SBM and control groups. Relative
to controls, the SBM group had reduced volumes in the cerebellar
hemispheres and pericallosal gray matter (the region including the basal
ganglia), although only the pericallosal gray matter was significantly
correlated with motor adaptation. Congenital cerebellar dysmorphology is
associated with preserved motor skill learning on voluntary, nonreflexive
tasks in children with SBM, in whom the relative roles of the cerebellum
and basal ganglia may differ from those in the adult brain.
(JINS, 2006, 12, 598–608.)