High/Low Autism Spectrum Behaviors and Executive Function

Background: Last year, we demonstrated the usefulness of the Executive Function Index (EFI, Spinella, 2004) with regard to a non-clinical sample by examining the relationship between high functioning Autism Spectrum disorder (HFA), as measured by the Autism Spectrum Quotient (ASQ) questionnaire, and underlying neuropsychological performance (frontal lobe, executive function).  The EFI is a quick, reliable, and valid indicator of various domains of executive function and appears useful for those investigating the impact of frontal lobe deficit on HFA individuals.  The ASQ can also rapidly quantity where an individual falls on the autism-normality continuum by distinguishing clinically significant levels of autistic traits.
Objectives: We used the High/Low ASQ score dichotomy (Lindell et al, 2009, Laterality; High ASQ scores of 16-30), Low ASQ scores of 5-15).  They found reduced hemispheric asymmetry for language processing, which has been highlighted in autistic populations, can be observed in a normal, non-clinical sample using theHigh/Low ASQ dichotomy.  We applied this High/Low dichotomy to provide converging evidence.
Methods: One-hundred undergraduates took the ASQ (50 questions, 10 each in 5 domains including social skill, attention switching, attention to detail, communication, and imagination) and the EFI.  (27 self-report items that measures areas associated with frontal lobe function including motivational drive, strategic planning, organization, impulse control, empathy, plus a total score).  In 2009, we showed that increases in ASQ score (suggesting more HFA behaviors), resulted in decreases in EFI scores (suggesting more executive function deficit, especially for Motivational Drive, Organization, and EFI Total Score).  We used the Lindell et al (2009) dichotomy to further test this relationship. 
Results: A total of 67 subjects scored in the Low ASQ range (5-15, mean ASQ = 10.99, SD = 2.52); 33 scored in the High ASQ range (16-30, mean = 20.27, SD = 3.52).  None scored above 32, a cut-off established by Baron-Cohen et al. (2001).  The correlations of ASQ and EFI across subjects remained the same as in 2009: Motivation/ Drive (r = - .22, p < .02), Impulse Control (r = -.04, p = .36), Empathy (r = - .16, p = .056), Organization (r = - .26, p < .01), Strategic Planning (r = - .11, p = .15),  EFI Total (r = - .26, p < .01).  A one-way ANOVA, with High ASQ/Low ASQ as the between-subjects factor, resulted in a similar pattern: Motivation/Drive F = 2.69, p = .10; Impulse Control F = .96, p = .33; Empathy F = 1.33, p = .25; Organization F = 3.67, p = .058; Strategic Planning F = 2.05, p = .14; EFI Total F = 5.86, p < .02.   
Conclusions: The significant associations observed in 2009 persisted (as ASQ increases, EFI decreases) using the High/Low ASQ dichotomy.   EFI Total score results suggest that the various EFI components all show decrement with ASQ increases.  We are refining these results by examining these relationships using the  RBANS (Randolph, 1998) neuropsychological test battery.