The corpus callosum (CC) is one of several brain structures affected
in children prenatally exposed to alcohol. This structure plays a major
role in coordinating motor activity from opposite sides of the body,
and deficits in bimanual coordination have been documented in
individuals with agenesis of or damage to the CC, particularly when the
task is performed without visual feedback. The Bimanual Coordination
Test was used to assess speed and accuracy on a task where both hands
must coordinate to guide a cursor through angled pathways providing
measures of interhemispheric interaction or the ability of the two
hemispheres to coordinate activity via the corpus callosum.
Twenty-one children with fetal alcohol spectrum disorders (FASD) and 17
non-exposed control children (CON), matched closely in age, sex, and
ethnicity were tested. For trials with visual feedback (WV), children
with FASD were slower than CON children but were equally accurate.
Although statistically significant group differences were not observed
on most trials completed without visual feedback (WOV), accuracy of the
FASD group on WOV trials was highly variable. Group differences in
accuracy on WOV angles approached significance after accounting for
performance on the WV angles, and children with FASD were significantly
less accurate on an individual angle believed to be particularly
sensitive to interhemispheric interaction. These results indicate that
children with FASD are slower than CON children but equally accurate on
basic visuomotor tasks. However, as task complexity and reliance on
interhemispheric interaction increases, children with FASD demonstrate
variable and inaccurate performance. Preliminary analyses suggest that
inaccurate performance on the bimanual coordination task, and
presumably impaired callosal functioning, may be related to the
attention and problem solving impairments commonly reported in children
with FASD. (JINS, 2004, 10, 536–548.)