Executive function is affected in autism spectrum disorder, but does not correlate with intelligence.

INTRODUCTION

Studies of executive function in autism spectrum disorder without intellectual disability (ASD-WID) patients are contradictory. We assessed a wide range of executive functioning cognitive domains in a sample of children and adolescents with ASD-WID and compared them with age-, sex-, and intelligence quotient (IQ)-matched healthy controls.

METHODS

Twenty-four ASD-WID patients (mean age 12.8±2.5 years; 23 males; mean IQ 99.20±18.81) and 32 healthy controls (mean age 12.9±2.7 years; 30 males; mean IQ 106.81±11.02) were recruited.

RESULTS

Statistically significant differences were found in all cognitive domains assessed, with better performance by the healthy control group: attention (U=185.0; P=.0005; D=0.90), working memory (T51.48=2.597; P=.006; D=0.72), mental flexibility (U=236.0; P=.007; D=0.67), inhibitory control (U=210.0; P=.002; D=0.71), and problem solving (U=261.0; P=0.021; D=0.62). These statistically significant differences were also found after controlling for IQ.

CONCLUSION

Children and adolescents with ASD-WID have difficulties transforming and mentally manipulating verbal information, longer response latency, attention problems (difficulty set shifting), trouble with automatic response inhibition and problem solving, despite having normal IQ. Considering the low executive functioning profile found in those patients, we recommend a comprehensive intervention including work on non-social problems related to executive cognitive difficulties.