Intelligence and executive functioning in adolescence: comparing autism spectrum disorder and typical development

Area of Science:

• Neurodevelopmental Disorders
• Cognitive Neuroscience
• Developmental Psychology

Background:

• Autism Spectrum Disorder (ASD) is a neurodevelopmental condition impacting social communication and behavior.
• Executive functions (EF) are crucial cognitive processes, including planning and cognitive flexibility.
• Understanding the interplay between intelligence and EF in adolescents with ASD without intellectual disability (ASD-WID) is vital for targeted support.

Purpose of the Study:

• To investigate the relationship between intelligence (IQ) and executive functions (EF) in adolescents with ASD-WID.
• To examine the influence of IQ level and sex differences on EF.
• To compare EF performance between ASD-WID and typically developing (TD) peers matched for age and IQ.

Main Methods:

• 214 adolescents (118 ASD, 96 TD; aged 12-18) were assessed.
• Executive functions were measured using the Wisconsin Card Sorting Test (WCST) and Color Trails Test (CTT).
• Cognitive ability was assessed using WISC-R/WAIS-R; non-parametric statistics were applied due to non-normal data distribution.

Main Results:

• No overall EF differences were observed between ASD and TD groups when matched for age and full-scale IQ.
• Higher IQ correlated with better planning and cognitive flexibility in both ASD and TD groups.
• High-IQ ASD adolescents performed comparably to high-IQ TD peers, suggesting potential compensatory mechanisms. Lower IQ in ASD was associated with more perseverative errors.

Conclusions:

• Intelligence, particularly perceptual reasoning, significantly influences EF outcomes in adolescents with and without ASD.
• High IQ may mitigate EF deficits in ASD-WID, while lower IQ is associated with pronounced executive control difficulties.
• Assessment and interventions should consider individual cognitive profiles rather than relying solely on diagnostic status.