DEFICIT OR DELAY? EXECUTIVE FUNCTIONS IN 8-TO 17-YEAR-OLDS WITH BORDERLINE INTELLECTUAL FUNCTIONING

Background
Executive functions (EFs) in children and adolescents with mild intellectual disability (MID) or borderline intellectual functioning (BIF) are frequently perceived as ‘deficient’ compared to typically developing peers. This cross-sectional study diverges from pointing out EF-deficits, but investigates if there may be delayed development of EFs from 8-17 years particularly for youth with BIF.

Methods
409 youths participated (aged 8.02-17.99; stratified per year), with MID, BIF or average intelligence (AIQ). EFs working memory, focused attention, cognitive flexibility, and inhibition were measured with performance tasks in a mobile app.

Results/Aims
BIF and MID youth scored similarly on cognitive flexibility from 8-to-12 years old, both lower than AIQ (F=8.46,p<.001). From 13 years old on, cognitive flexibility scores of BIF youth were similar to AIQ (F=20.69,p<.001). These delay-patterns for BIF were also found for focused attention; reaching similar levels as AIQ youth during adolescence. Working memory scores of children with MID and BIF were similar from 8-12; both lower than AIQ (F=6.65,p<.01). During adolescence working memory scores diverged for all three IQ-groups, who differed significantly from one another (F=22.58,p<.001). In-depth analyses on inhibition are forthcoming.

Conclusions
This cross-sectional study shows a potential delayed development of EFs: focused attention and cognitive flexibility for youth with BIF from 8-to-17.
From Science to Practice
Our study provides a positive perspective for delayed versus deficient abilities of 8-to-17-year-olds with BIF. This impacts the lowering of our expectations about their cognitive abilities and overestimation during childhood, and focuses on supporting development of these cognitive attention abilities more so during adolescence, for example for academic performance.