Prefrontal lesions and attentional skills in childhood.

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 prefrontaj 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.