Inhibition difficulties in preterm children: Developmental delay or persistent deficit?

Among executive functions (EFs), research has highlighted specific inhibition difficulties in preterm children. The present paper reviews and classifies the studies that assessed response inhibition and interference control abilities in preterm children and adolescents aged 3 to 16 years. Most behavioral studies agree on a developmental delay at early school age in inhibition abilities and a catch-up before adolescence, with lesser response inhibition difficulties at pre-adolescence. However, persisting interference control difficulties have been reported into early adulthood. These results are discussed, along with functional magnetic resonance imaging (fMRI) findings. Finally, this paper outlines methodological issues that need to be overcome in order to define the developmental trajectory of inhibition abilities in the preterm population.     

Development of the ability to inhibit a prepotent response: Influence of working memory and processing speed

This study aimed to examine developmental trends in response inhibition during childhood and to control for possible developmental influence of other basic cognitive processes (such as working memory and processing speed). In addition, we explored the relationships between response inhibition, working memory, and processing speed, as they are thought to be integral to cognitive control. Therefore, we assessed these three cognitive abilities in 159 children aged from 5 to 12. Results showed an improvement in response inhibition ability from 5 to 10 years of age. This improvement remained significant after controlling for the influence of working memory and processing speed. Furthermore, the developmental relationships showed an early differentiation between response inhibition, working memory, and processing speed. Thus, these processes were independent and need to be treated as such in further studies.     

Response inhibition difficulties in preterm children aged 9–12 years: Relations with emotion and behavior

Previous studies with children have demonstrated inhibition difficulties associated with prematurity, but the question of potentially catching up with a delay in inhibition processes before adolescence still remains. Moreover, preterm adolescents are more at risk than their term-born peers for presenting behavioral problems such as emotional difficulties and attention deficit/hyperactivity disorder. In addition to examining response inhibition, this study addressed, for the first time, the impact of an emotional context on response inhibition abilities and its relation to behavioral problems in late school-aged preterm children. Fifty-eight preterm children aged 9–12 years were compared with 61 controls on two versions of a stop-signal task, the Delay Frustration Task, and the Strengths and Difficulties Questionnaire. Results showed general difficulties in inhibiting a response, rather than a specific impact of emotional context in preterm children. Compared with controls, these children exhibited more and longer button presses in a delay situation, as well as faster go reaction times associated with lower probability of inhibition in the stop-signal tasks. These difficulties reflected impulsivity and were associated with higher hyperactivity/inattention and conduct problems. Additionally, intrauterine growth restriction was found to be an additional perinatal risk factor for hyperactivity/inattention symptoms. These findings suggest that remaining inhibition difficulties in the preterm population at preadolescence could reveal increasing behavioral issues.     

Gestational age and gender influence on executive control and its related neural structures in preterm-born children at 6 years of age

Within preterm-born children, being born male and at a lower gestational age (GA) have both been associated with a heightened risk for developmental difficulties. However, in this population little is known about the combined effect and the influence of these risk factors on cortical structures and executive control. In the present study, 58 preterm-born children (GA ranging from 24.0 to 35.1 weeks) were administered the computerized Child Attention Network Task at 6 years of age. Brain magnetic resonance imaging was performed and analyzed using Voxel-Based Morphometry (VBM) in all children. At a behavioral level, boys born <28 weeks of GA had significantly less executive control than preterm-born girls <28 weeks (p = .001) and preterm-born boys ≥28 (p = .003). The reduced executive control in preterm-born boys <28 weeks gestation was related to lower cortical densities in the inferior frontal gyrus (IFG) and dorsolateral prefrontal cortex (DLPFC). The current study links the higher incidence of reduced executive control in preterm-born boys to a higher degree of prematurity (low GA) and identifies brain structural abnormalities in the prefrontal cortex related to these deficits. The implications of these results are discussed.     

Basic visual perceptual processes in children with typical development and cerebral palsy: The processing of surface,length, orientation,and position

The present study aims to assess how the processing of basic visual perceptual (VP) components (length, surface, orientation, and position) develops in typically developing (TD) children (n = 215, 4–14 years old) and adults (n = 20, 20–25 years old), and in children with cerebral palsy (CP) (n = 86, 5–14 years old) using the first four subtests of the Battery for the Evaluation of Visual Perceptual and Spatial processing in children. Experiment 1 showed that these four basic VP processes follow distinct developmental trajectories in typical development. Experiment 2 revealed that children with CP present global and persistent deficits for the processing of basic VP components when compared with TD children matched on chronological age and nonverbal reasoning abilities.