What is executive function?
Executive function (EF) describes the “overarching regulation of goal-directed, future-oriented, higher-order cognitive processes” largely controlled by the frontal cortex (Szczepanski & Knight, 2014; Demetriou et al., 2019). These higher-order functions include skills related to planning, organizing, self-regulation, attention maintenance, emotion regulation, prioritizing, and staying on task. EF skills develop intensely from infancy to the preschool period and steadily improve into early adulthood (Carlson et al., 2013).
Theoretical models describing the development of EF and potential connections to distinct parts of the brain vary. Cognitive and behavioral models tend to focus on attentional control and the distinction between individual EF domains (EFs) (Miyake et al., 2000; Diamond, 2013; Posner, 1980; Shallice & Burgess, 1991). The number of discrete EFs within these models ranges from 2 to more than 30 and they can generally be described as hot – functions supported by emotional awareness and social cognition – or cool – functions related to mechanistic skills where emotions aren’t a factor (Miyake & Friedman, 2012; Baggetta & Alexander, 2016; Perone et al., 2018; Zelazo & Carlson, 2012).
Neurobiological and neural models of EF suggest a broader and more complex interaction of various brain regions where discrete EFs don’t necessarily apply (Barrasso-Catanzaro & Eslinger, 2016). These theories look at the roles of neurotransmitters and genetic factors in EF function and use neuroimaging to assess broader brain networks (Logue & Gould, 2014; Buschbaum et al., 2005; Alvarez & Emory, 2006).
Executive function and autism spectrum disorder (ASD)
Studies linking autism spectrum disorder (ASD) and EF normally use cognitive or behavioral models and primarily focus on comparing discrete EFs function across diagnostic groups. In most cases, discrete functions can be broken down into three processes/EFs (Hill, 2004):
- Working memory, which dictates one’s ability to retain and manipulate information over short periods of time;
- Set shifting/Cognitive flexibility, which assists in maintaining or shifting focus and attention in response to different demands, rules, or settings;
- Response inhibition/Self-control, which enables one to resist impulsive actions and helps in setting priorities
In a 1996 review, Pennington & Ozonoff posited that the above EFs might serve as cognitive markers for discerning between ADHD, ASD, and other neurodevelopmental disorders. A later review by Hill (2004) proposed the executive dysfunction hypothesis which suggested distinct EF domain impairment and notable heterogeneity (diversity) in EF presentation across studies and within groups. Hill suggests that as the investigation of EF profiles in different clinical populations continues, executive dysfunction could serve as a specific diagnostic marker for ASD and other neurodevelopmental disorders in the future.
Extant literature on the link between EF and ASD suggests impairment in various EFs across the life span – where some impaired EFs reduce with age and others persist (de la Vega, et al., 2014; Guerts et al., 2014). Impairment in discrete EFs is confirmed however, uncertainty remains regarding the mechanisms and pathways underpinning EFs presentations. Contemporary studies aim to determine if EFs are differentially impaired or a common mechanism exists (Demetriou et al., 2018; Lai et al., 2017).
The excitation/inhibition hypothesis (EI) suggests the imbalance in neural excitation and inhibition in the brain circuitry contributes to EF impairment in ASD (Rubenstein & Merzenich, 2003; Hegarty et al., 2018). Evidence supporting these assumptions exists, though the links between EF, EI, and ASD have not been substantially explored.
What does executive function impairment (executive dysfunction) look like in autism?
Other EFs described within extant EF literature include planning, organizing, time management, meta-cognitive regulation, attention control, monitoring, social interactions, communication, initiating actions, verbal reasoning, emotional regulation, behavioral regulation, daily living, etc. Due to such diverse presentations (heterogeneity) of EF impairment, a universal EF profile for individuals with ASD has not been determined (Panerai et al., 2014).
In day to day life, EF impairments can present as:
- Forgetting to pack a school bag or packing the wrong things
- Difficulty organizing a calendar
- Struggling with homework (losing, forgetting, not completing)
- Inability to begin or complete a task
- Forgetting or running late for appointments
- Constantly misplacing items
- Accidentally skipping meals or showers
- Inability to drive without GPS
- Difficulty recognizing a task that needs to be done
- Struggling to break a task into smaller steps
- Difficulty self-monitoring, or figuring out what is “wrong” in one’s environment or body
- Forgetting or mixing up practical instructions (i.e. directions, household chores, etc.)
- Difficulty keeping up in conversations
- Forgetting names and/or faces
Presentation of EF impairment depends on the presence of comorbid traits, learning disabilities, and an individual’s age (Happe et al., 2006). Studies suggest that specific EF impairments in individuals with ASD change significantly with age compared to control groups. Specifically, various everyday EFs (i.e. inhibition, working memory, planning, etc) can improve with age while EFs related to emotional control and set-shifting have no significant relationship to age (Kouklari et al., 2018; Noggle et al., 2015).
Treatments and supports
Treatment options are specific to individual cases. For individuals with autism, treating comorbid conditions such as anxiety, depression, GI issues, etc., can help reduce EF difficulties. For some, organizational aids, timers, notebooks, assistive devices, etc. help with organization and memory (Wallace et al., 2016; Robinovici et al., 2015). In other cases, medication and behavior therapy is used. Recent studies have found encouraging results for the positive effect of mindfulness and physical practices on EF impairment. These can include yoga, meditation, martial arts, aerobics, etc., which all require dedicated and repetitive practice (Otero et al., 2014; Tang et al., 2012). If you think you or a loved one is struggling with executive functioning, talk to your general practitioner and consult with your family and/or friends to create a supportive environment and plan.
Learn about the role of underlying neuroanatomy in executive function with Greg Wallace, Ph.D. in his Research Updates Webinar.
Learn practical strategies and activities to strengthen and support EF skills at home with Amy Moor Gaffney, M.A., CCC-SLP in her webinar.