Executive functions of children born very preterm—deficit or delay?

Abstract

This cross-sectional study examined the performance of children born very preterm and/or at very low birth weight (VPT/VLBW) and same-aged term-born controls in three core executive functions: inhibition, working memory, and shifting. Children were divided into two age groups according to the median (young, 8.00-9.86 years; old, 9.87-12.99 years). The aims of the study were to investigate whether (a) VPT/VLBW children of both age groups performed poorer than controls (deficit hypothesis) or caught up with increasing age (delay hypothesis) and (b) whether VPT/ VLBW children displayed a similar pattern of performance increase in executive functions with advancing age compared with the controls. Fifty-six VPT/VLBW children born in the cohort of 1998-2003 and 41 healthy-term-born controls were recruited. All children completed tests of inhibition (ColorWord Interference Task, Delis-Kaplan Executive Function System (D-KEFS)), working memory (Digit Span Backwards, HAWIK-IV), and shifting (Trail Making Test, Number-Letter Sequencing, D-KEFS). Results revealed that young VPT/VLBW children performed significantly poorer than the young controls in inhibition, working memory, and shifting, whereas old VPT/VLBW children performed similar to the old controls across all three executive functions. Furthermore, the frequencies of impairment in inhibition, working memory and shifting were higher in the young VPT/ VLBW group compared with the young control group, whereas frequencies of impairment were equal in the old groups. In both VPT/VLBW children and controls, the highest increase in executive performance across the ages of 8 to 12 years was observed in shifting, followed by working memory, and inhibition. Conclusions: This study provides evidence that (a) poor performance in inhibition, working memory, and shifting of young VPT/VLBW children might reflect a delay rather than a deficit and (b) that VPT/VLBW children are likely to display a similar pattern of performance increase in these three executive functions compared with that of controls.

Executive Function in Adolescents Born <1000 g or <28 Weeks: A Prospective Cohort Study

“…Furthermore, longitudinal reports of EF in EP/ELBW samples into adolescence are scarce. 9,10 Catch-up to age-expected levels by adolescence has been reported for some cognitive skills (receptive vocabulary) but not others (general intellectual functioning). 11 In a cross-sectional study, EF deficits appeared more pronounced in younger preterm children than in older preterm children, relative to controls.…”

“…11 In a cross-sectional study, EF deficits appeared more pronounced in younger preterm children than in older preterm children, relative to controls. 10 Of clinical importance, however, this has not been well-explored in longitudinal data sets. Adolescence is an important period of development for EF skills, 12 and hence it is crucial to assess EF skills comprehensively and longitudinally in contemporary adolescent cohorts.…”

“…Altered maturational trajectories have been identified in other cognitive domains in preterm adolescents, 11 and in EF from early to middle childhood. 10,43 However, longitudinal reports of EF into older adolescence are limited. Although ceiling effects of tests are an important consideration in longitudinal studies of cognitive development, the RCF is used widely in children and adults, and we saw improved accuracy toward normative young adult levels 44 in both groups over the follow-up period.…”

Effects of two different memory training approaches in very preterm-born children

“…On a cognitive [34] but also on a neural [35] and functional network level [36,37] group differences were significantly more pronounced between our preterm and control samples at a younger (7-8 and 9-10 years) age than at an older (11-12 years) age. The observation of a maturational catch-up at early school-age in very preterm-born children might be associated with high training-induced plasticity after our rather short memory training programs.…”

Physiotherapy intervention for 4-5 year old children born extremely preterm and/or extremely low birth weight

“…Persistence of executive dysfunction challenges the suggestion by Ritter et al that problems related to executive function are more of a delay rather than a deficit (Ritter et al, 2013). However, comparison between the findings by Burnett et al with those by Ritter et al needs caution as the studies differ, in terms of age of the children and degree of prematurity.…”