Despite the potential impact on development, few studies have examined
the influence of prefrontal lesions occurring prior to maturation of the
central nervous system. This study investigates the effect of prefrontal
lesions in general, as well as the impact of lesion laterality, with
respect to attentional abilities. The sample comprised 36 children with
prefrontal lesions and 40 healthy controls. Attentional function was
assessed across four domains: selective, shifting and divided attention,
and processing speed. Group mean performances for children with prefrontal
lesions indicated global attentional deficits, with greatest difficulties
for “higher-order” skills including shifting and divided
attention. Children with left prefrontal lesions performed similarly to
controls, with a specific deficit characterized by difficulties with
on-line processing of auditory-verbal information. Right prefrontal
lesions were primarily associated with impairments in day-to-day executive
functions, including reduced monitoring, poor shifting attention and
disinhibition. Children with bilateral prefrontal lesions performed worse
than controls on tasks requiring greater cognitive resources. These
results provide evidence of the important role played by prefrontal cortex
in the development of attentional skills, and the particular role of the
right prefrontal cortex. The pattern of attention deficits observed
following early prefrontal lesions suggests some lateralization of
function within the frontal lobes, even during childhood. (JINS,
2005, 11, 817–831.)Source of
funding: Australian National Health and Medical Research Council,
Australian Research Council, Murdoch Children's Research
Institute.