What is executive function?

Wallace defines executive function (EF) as an umbrella term describing a set of cognitive processes that dictate behavioral regulation and influence the ability to attain proximal goals. These processes include working memory, cognitive flexibility, inhibitory control, and more (3:28). The speaker demonstrates how EF processes regulate thoughts, actions, and emotions to achieve goals like math homework, group chats, and adaptive functioning (5:41). Therefore, he continues, EF is critical to independence and our ability to function optimally in daily life as it provides context and longitudinal predictability for real-world outcomes (6:27). 

EF was first linked to autism in the 1970s (7:54) and described using the Wisconsin Card Matching Test, which assesses cognitive flexibility (11:50). Cognitive flexibility, the most frequently occurring EF challenge in autism, affects one’s ability to transition from one activity to another, accept changes in routines, and manage violations of expectations (12:20). 

Research questions and methods

Wallace details the Behavior Rating Inventory of Executive Function (BRIEF) (16:32) and presents research questions addressed by him and his team (19:40): 

1. What is the profile of real-world EF problems among autistic children, adolescents, and young adults? 
2. Do these EF issues predict co-occurring psychopathology (i.e., anxiety and depression symptoms), which negatively impact outcomes in autistic children, adolescents, and young adults?

The speaker and his colleagues conducted three studies to address these questions. Each study utilized the BRIEF and a second rating scale specific to participant age and study purpose. Results split aspects of EF into two categories: the Behavior Regulation Index (BRI), which includes flexibility and inhibition, and the Metacognition Index (MI), which includes working memory and planning/organizing. Researchers ran controlled regressions (age and IQ) for each study.  

Study 1: Executive function profile of autistic children and adolescents

210 autistic children and adolescents (5 – 18 years old) without intellectual disability (83% male) completed the BRIEF and the Child Behavior Checklist (CBCL) (20:38). The EF profile showed clinically significant scores (1.5 standard deviations) across numerous domains, with the highest in flexibility (21:10). Regression analyses revealed that BRIEF indices predicted symptoms of depression and anxiety well beyond the influence of age and IQ. Specifically, BRI predicted anxiety symptoms, and BRI & MI predicted depression symptoms (22:33). 

Study 2: Executive function profile of autistic young adults

Thirty-five autistic young adults without intellectual disability (31 male) completed the BRIEF and the Adult Behavior Checklist (ABCL) (24:11). Results showed high scores across the board, with planning and organizing as the most clinically significant. Regressions found that BRI predicted anxiety symptoms while MI (alone) predicted depression symptoms (24:51). 

Wallace asserts that these two studies reveal autistic children, adolescents, and young adults have difficulties with flexibility. However, MI issues are more prominent than BRI issues in autistic young adults which could be due to earlier maturation of BRI in the non-autistic population or expectations of adulthood that align with MI skills (26:30). As MI and BRI predicted depression and anxiety symptoms, the speaker posits that EF as a treatment target could have positive downstream influences on co-occurring symptoms that negatively impact life satisfaction and quality (28:14). 

Study 3: The role of executive function challenges in outcomes for autistic individuals

This study aimed to evidence the way EF challenges play in outcomes (community-based paid employment) for autistic individuals, especially those with intellectual disabilities (28:52). 628 participants with an autism diagnosis (59% female) from diverse socioeconomic backgrounds with an average age of 39 completed a series of self-reports and outcome measures (BDEFS, FS-R) as well as subjective quality of life (QoL) and daily living skills assessments (WHOQOL-BREF, ASQOL, W-ADL) (31:20). Controlled linear regressions (35:24) revealed that ER difficulties are related to lower physical and psychological QoL and that social relationship QoL decreases with autistic traits, and EF, and age. Increased EF correlates with lower autism-specific QoL (36:30), and living skills increased with age, although low inhibitory control and flexibility correspond with poorer daily living skills (39:09). 

Conclusions

Based on these findings, Wallace concludes that EF is linked to subjective QoL and daily living skills outcomes across autistic adulthood. Further, he continues, such links between EF and adult outcomes suggest that differential interventions, accommodation, and support services must be based on a desired development or improvement (40:00). The speaker asserts that these studies evidence the critical importance of EF to real-world outcomes in autism. While intervention developments for children and adolescents are well underway, services and supports beyond early adulthood are severely lacking (43:26). Wallace touches on future research directions (41:34) before opening the question and answer session, where he discusses apparent gender biases and more (45:15).