Neurobehavioral evidence for working-memory deficits in school-aged children with histories of prematurity

Abstract

Cognitive performance in 7- to 9-year-old preterm neonatal intensive-care survivors was compared with that in age-matched control children. Non-verbal memory span, spatial working-memory abilities, planning, set-shifting, and recognition memory for both spatial and patterned stimuli were assessed using the Cambridge Neuropsychological Testing Automated Battery. Relative to children in the control group, neonatal intensive-care unit (NICU) survivors demonstrated 25% more memory errors on the spatial working-memory task. Their use of strategy on this task was similar to a control group of 5-year-olds. Planning times on 'Tower of London' problems were long relative to those of term controls. NICU survivors demonstrated poorer pattern recognition as well as a shorter spatial memory span. The groups did not differ in visual-discrimination learning or in spatial-recognition memory. No specific neonatal risk factor accounted for the observed differences, although scores on the Neurobiological Risk Score (NBRS), a composite measure of neonatal risk, did predict several aspects of later task performance. Whether these data reflect a developmental delay in brain maturation in NICU survivors or the presence of a permanent information-processing deficit due to adverse neonatal events must be assessed through continued follow-up.

Everyday Memory and Cognitive Ability in Children Born Very Prematurely

“…It is not known as yet whether the individual children with everyday memory difficulties reported here also demonstrate insult to the hippocampus\medial temporal lobe . Frontal-cortical pathways have recently been suggested as an organic basis for cognitive deficits in premature children that contribute to difficulties on more complex measures of short-term or working memory (Luciana, Lindeke, Georgieff, Mills, & Nelson, 1999).…”

Executive functioning in preschool children born very preterm: Relationship with early white matter pathology

“…These skills refer to a set of processes necessary for purposeful, goal-directed behavior (Welsh & Pennington, 1988). Several studies suggest that by school-age, very preterm children are characterized by a range of executive difficulties, including poor planning and problem solving, impaired working memory and disinhibition (Anderson et al, 2004;Luciana et al, 1999;Taylor et al, , 2006. Importantly, these difficulties have been shown to predict later educational outcomes (e.g., mathematics; Assel et al, 2003).…”

Perinatal pH and Neuropsychological Outcomes at Age 3 Years in Children Born Preterm: An Exploratory Study

“…On average, children born preterm perform lower on intelligence tests than their fullterm peers by 5 to 11 points, with a "dose-response" effect noted as a function of birth weight, even after adjusting for sociodemographic influences. As these observed differences on intelligence tests can be considered to represent the amalgam of skill discrepancies in more discrete cognitive operations (Aylward, 2005), finer-grained examinations of specific neuropsychological abilities reveal deficits in motor coordination and tone (e.g., Breslau, Chilcoat, & Johnson, 2000), fine motor-visuomotor skills (e.g., Dewey, Crawford, & Creighton, 1999;Whitfield, Eckstein-Grunau, & Holstik, 1997), and attention and executive functions, particularly working memory (e.g., Anderson & Doyle, 2004;Espy et al, 2002;, Luciana, Lindeke, Georgieff, Mills, & Nelson, 1999;Taylor, Hack, & Klein, 1998). In preschoolers, language delays are common.…”

“…Second, perinatal pH was unrelated to performance on tasks that demanded maintaining information in working memory. Working memory often is impaired in samples of children born preterm (e.g., Espy et al, 2002;Luciana et al, 1999), even in those at low risk. If pH is a generalized marker of neural integrity, pH would be expected to be related to working memory task performance as well.…”