Inhibitory Control Following Perinatal Brain Injury

Evidence from developmental, lesion, and neuroimaging studies indicates that the prefrontal cortex plays a major role in executive abilities, including inhibitory control. Proficient executive performance, however, relies not only on the integrity of the prefrontal cortex but also on its interactions with other brain regions. In the current study, the authors focused on the effect that early damage to the white matter tracts interconnecting prefrontal and other brain regions has on inhibitory control. Data were collected from 13 children with bilateral spastic cerebral palsy and from a control group of 20 children with no history of neurologic compromise. Converging evidence from 3 separate paradigms is presented that strongly suggests these children experience impairments in inhibitory control. Findings are discussed within the context of current cognitive and neuroanatomical models of inhibition. Executive ability is a broad term used to describe an assemblage of higher order cognitive abilities such as strategy use, cognitive flexibility, and inhibitory control (Pennington, 1997; Stuss, 1992). Although spanning a broad spectrum, all of these abilities require the efficient coordination and integration of information across a variety of sensory modalities and cognitive domains (e.g., visuoperceptual, language, and memory). From a neuroanatomical perspective, cognitive integration of this nature appears to be most heavily mediated by a common brain region, the prefrontal cortex (Stuss, Alexander, & Benson, 1997). Because the prefrontal cortex has numerous interconnections with other brain regions, it is well suited to support the synchronization of widely distributed neural activity (Cummings, 1995; Thatcher, 1997). The prefrontal cortex is the last brain region to reach maturity, with development continuing into early adulthood (Krasnegor, Lyon, & Goldman-Rakic, 1997). A particularly important aspect of prefrontal development, and the subsequent enhancement of executive abilities, is the refinement of intricate white matter connections between the prefrontal cortex and other brain regions. Thatcher (1997) suggested that the refinement of prefrontal connections stems from cyclical patterns of neural growth during which synapses are rapidly generated and then selectively pruned. The re