Are executive skills primarily mediated by the prefrontal cortex in childhood? Examination of focal brain lesions in childhood

Abstract

Introduction Based on the study of adults with brain insult, traditional localizationist views have argued that executive skills are primarily mediated by prefrontal cortex. It remains unclear whether a similar pattern of localization exists in childhood.Methods To investigate this hypothesis, we compared the performance of children, aged 7-16 years, with radiological evidence of brain pathology. The sample was divided according to lesion location as follows: frontal pathology (n=38), extra-frontal pathology (n=20), generalized pathology (n=21) and healthy controls (n=40). Using a multidimensional model of executive function described by Anderson (2002) and Anderson (1998; Anderson et al., 2001c, 2001d), these groups were compared on a range of executive function domains including: attentional control, goal setting, cognitive flexibility, and information processing. Additional, non-executive measures were also administered.Results Contrary to adult lesion-based studies, there was little differentiation in executive processes between frontal and extra-frontal groups.Conclusions These results provide support for contemporary models which propose a distributed, but integrated neural network for executive skills, suggesting that the integrity of the entire brain is necessary for adequate executive functions in childhood. Further, focal lesions to any brain region during development may render children vulnerable to a range of executive deficits that would not normally be expected following similar pathology in adulthood.