Child Neuropsychol. 2015;21(3):331-53. doi: 10.1080/09297049.2014.906568.
Complementary assessments of executive function in preterm and full-term preschoolers.
Loe IM, Chatav M, Alduncin N.
Division of Neonatal and Developmental Medicine, Department of Pediatrics , Stanford University School of Medicine , Stanford , CA , USA.
Executive functions (EFs) are interrelated cognitive processes that have been studied in relation to behavior, attention, academic achievement, and developmental disorders. Studies of EF skills assessed through parent report and performance-based measures show correlations between them ranging from none to modest. Few studies have examined the relationship between EF skills measured through parent report and performance-based measures in relation to adaptive function. The present study included preschool children born preterm as a population at high risk for EF impairments. Preschool children (N = 149) completed a battery of EF tasks that assess working memory, response inhibition, idea generation, and attention shifting or cognitive flexibility. Parents reported on children’s EF and adaptive skills. Preterm children showed more parent-rated and performance-based EF impairments than did full-term children. The combined use of either parent report or performance-based measures resulted in the identification of a large number of children at risk for EF impairment, especially in the preterm group. Both parent report and performance-based EF measures were associated with children’s adaptive function. EF skills are measurable in young child’ren, and we suggest that EF skills may serve as targets for intervention to improve functional outcomes. We recommend the use of both parent report and performance-based measures to characterize children’s EF profiles and to customize treatment.
KEYWORDS: Adaptive function; Behavior Rating Inventory of Executive Function; Executive function; Premature birth; Working memory
Background. Executive function (EF) is often used as an umbrella term that refers to several interrelated cognitive processes used to regulate and direct one’s behavior. EF skills may include inhibition, the ability to inhibit or resist an automatic response or action; working memory, the ability to recall or hold information in one’s mind despite competing information or while manipulating other information; cognitive flexibility, the ability to switch back and forth between rules or tasks; and other higher-order skills, such as organizing, sequencing and planning. Importantly, EF skills are related to functional outcomes, including academic achievement and social competence. In addition, impairments in EF skills are found in several neurodevelopmental disorders, such as Attention-Deficit/Hyperactivity Disorder (ADHD), autism, and learning disorders. Children with history of preterm birth are also at high risk of EF impairments and associated problems, including inattention and learning difficulties.
Objectives. We sought to characterize EF in preschoolers using both standardized parent ratings of EF skills and performance-based EF measures. We recruited 149 preschoolers, which included 70 children born preterm and 79 children born full-term. The preterm group served as a model of neurobiological risk for EF impairments. We examined the following:
- Group (preterm vs. full-term) differences in parent-rated and performance-based EF
- Age differences in performance-based EF
- Strength of associations between parent-rated and performance-based EF skills; as well as the ability of each method to identify children with EF impairments
- Whether parent-rated or performance-based EF contributed to children’s adaptive skills or overall function
Methods. Parents completed questionnaires about children’s EF skills and adaptive skills, a measure of children’s overall function based on questions about communication, social skills, motor skills, and daily living skills. Children completed a play-based battery of games/tasks that tap EF skills, such as response inhibition, cognitive flexibility, and working memory.
Figure 1. Preschool child completes the 6-boxes working memory task. Each box is baited with a treat, and the child must find each of the treats in the least number of reaches. The lid color or location of the box may be used as an aid for the child to remember which boxes have already been searched.
Results. We found that preterm preschoolers had more EF difficulties than full-term preschoolers based on both parent ratings and performance-based tasks. Younger children performed more poorly on EF tasks than older children.
Figure 2. Preschool child participates in the bird/dragon task, a measure of response inhibition and working memory. The child should follow the directions of the nice bird, but not the directions of the naughty dragon.
Figure 3. Results from the bird/dragon task. The preterm group performed more poorly than the full-term group. There was a main effect of age with younger children performing more poorly than older children. Similar patterns of results were found for the other EF tasks.
There were modest, statistically significant correlations between scores from parent-rated EF scales and performance-based EF tasks, although the EF constructs were not perfectly aligned. Identifying children with EF impairments based on parent ratings or performance-based tasks showed overlap—i.e., the two methods overlapped in identifying the same children with EF impairments; however, each method also identified unique children. Using either parent rating scales or performance-based measures to identify EF impairments raised the sensitivity and odds of identifying children in the preterm group compared to using either method alone.
We also examined whether EF contributed to children’s overall function. The models predicting to children’s overall function showed that both parent ratings of EF and performance-based EF scores made unique contributions to children’s overall function.
This study is important because it went beyond the typical study findings of preterm vs. full-term group differences in EF. We showed how parent-rated and performance-based EF scores correlate with each other, identify children with EF impairments, and are associated with children’s overall function. Past studies suggest that differences in ecological validity explain the discrepancy between parent-reported EF and directly measured/performance-based EF. Parent ratings tap into the use of EF skills in naturalistic settings, providing a global view of children’s behaviors in everyday environments. Lab-based EF tasks have face validity for EF constructs, but also take place in a controlled environment, with one-to-one attention and lack of distractions. Our findings that both parent-rated and performance-based EF contribute to functional outcomes suggest that both types of measures are ecologically valid and should be used as complementary assessments. We recommend standard screening of all children with EF-rating scales and additional monitoring and EF evaluation for high-risk groups, such as children born preterm. Performance-based EF measures may help characterize individual EF profiles and help to customize treatment.
Our other published manuscripts based on this sample also highlight the importance of both parent-rated and performance-based EF. We showed that both types of EF measures contribute to social competence.(1) We also found that EF acts as a mediator of the effects of gestational age on functional outcomes, including behavior problems, adaptive function, and reading.(2) Whether parent-rated and/or performance-based EF acted as a mediator varied as a function of outcome. For adaptive function, both types of measures mediated effects of gestational age; for prereading skills, only performance-based EF acted as a mediator; and for behavior symptoms, only parent-rated EF was significant. Given the associations between EF and functional outcomes, we suggest that EF skills may serve as targets for intervention to improve outcomes. Future research should focus on interventions for EF.
- Alduncin N, Huffman LC, Feldman HM, Loe IM. Executive function is associated with social competence in preschool-aged children born preterm or full term. Early Human Development. 2014;90(6):299-306.
- Loe IM, Feldman HM, Huffman LC. Executive function mediates effects of gestational age on functional outcomes and behavior in preschoolers. J Dev Behav Pediatr. 2014;35(5):323-33.
For more information, please contact:
Irene M. Loe, MD
Division of Neonatal and Developmental Medicine
Stanford University School of Medicine
750 Welch Road, Suite 315
Palo Alto, CA 94304.