Relationship Between Executive Functioning and Adaptive Functioning within Autism Spectrum Disorder (ASD).

Background:  Autism Spectrum Disorder (ASD) is a heterogeneous disorder with varying abilities across domains such as cognition, executive functioning, and adaptive skills. Cognitive abilities range from impaired to well above average with approximately 31% of diagnosed children having an intellectual disability (ID; Baio, 2014). Deficits in Executive Functioning (EF) are also commonly observed, but EF abilities are varied (Hill, 2004). Prior research has explored the relationship between EF and adaptive functioning in individuals with ASD (McLean, Harrison, Zimak, Joseph, & Morrow, 2014), but there is little literature examining this relationship in individuals with ASD with intellectual impairment. In individuals with ASD and typical cognitive abilities, deficits in the EF skills of metacognition have been associated with deficits in adaptive functioning (Gilotty, Kenworthy, Sirian, Black, & Wagner, 2002). By examining the relationship between EF and adaptive functioning in a population with cognitive deficits, greater understanding of the relationship between EF and adaptive functioning can be gained.

Objectives:  To 1) explore the relationship between EF and adaptive functioning in ASD and 2) expand our understanding of this relationship by incorporating children with ASD and cognitive impairment.

Methods:  Participants were 82 children who met strict (ADOS, ADI) criteria for ASD participating in a study focused on the biological basis of ASD (64 male, M_age = 12.41, range = 5.33-17.67). Forty-six individuals had an IQ of 70 or greater, and 36 individuals had an IQ of less than 70. Correlations were conducted between composites of the BRIEF and the composite and subdomain scores of the VABS. A series of hierarchical linear regressions were also conducted to determine the amount of variance in each of the VABS composite and domain scores that was accounted by IQ, Metacognitive Index (MCI) scores, and Behavior Regulation Index (BRI) scores.

Results:  Significant negative correlations were found between the BRI, MCI, and the four VABS measures for individuals with unimpaired cognitive functioning. Within this subgroup, MCI was a significant predictor of VABS Daily Living Skills (β = -.439, t(42) = -2.507, p < .05), and BRI was a significant predictor of VABS Composite (β = -.416, t(42) = -2.451, p < .05) and Socialization (β = -.569, t(42) = -3.410, p < .01). For individuals with IQs less than 70, significant negative correlations were found between the MCI and the VABS Composite, Communication, and Daily Living Skills. However, regression analyses indicated that only IQ significantly predicted performance on the VABS domains in this subgroup.

Conclusions:  Our results support previous findings indicating that in individuals with ASD and typical cognitive abilities, EF abilities are associated with adaptive skills. However, we found that EF abilities in the realm of behavior regulation were greater predictors of adaptive functioning than metacognitive abilities. While moderate correlations are found between metacognition and adaptive functioning domains in individuals with cognitive impairment, it does not appear that metacognitive abilities are significant predictors of adaptive functioning. Overall, findings suggest that the relationship between EF and adaptive functioning differs in individuals with ASD and cognitive impairment than individuals with ASD with intact cognitive abilities.