What are Executive Functions?

In a constantly changing environment, executive abilities allow us to shift our mind set quickly and adapt to diverse situations while at the same time inhibiting inappropriate behaviors. They enable us to create a plan, initiate its execution, and persevere on the task at hand until its completion. Executive functions mediate the ability to organize our thoughts in a goal-directed way and are therefore essential for success in school and work situations, as well as everyday living.¹

Though there is no official definition of the term “executive function(s),”² researchers agree that they can be defined as the cognitive control mechanisms that “allow us to shift our mind set quickly and adapt to diverse situations,” and “organize our thoughts in a goal-directed way,” enabling us to “create a plan, initiate its execution, and persevere on the task at hand until it’s completion.”²

Without a clear definition, then, it’s unsurprising that there is also no definitive list of which cognitive processes constitute individual executive functions. Currently the most frequently researched executive function terms in the scientific literature as a whole are working memory, inhibition, set-shifting (cognitive flexibility), planning, and fluency. ³ Not only are those only the tip of the EF iceberg, they aren’t even necessarily independent EFs at all. For example, the commonly-considered EF we call “planning” is actually a result of the core EFs of updating, shifting, and inhibition working together. ⁴

So, to keep things simple here at EDRA we usually list executive functions based off the eight EF subdomains identified in the Behavior Rating Inventory of Executive Function (BRIEF),^5,6 but it’s important to remember that it’s more of a “major factors” shortcut than anything like a comprehensive list.

• Working Memory
• Shifting/Cognitive Flexibility
• Inhibition/Impulse Control
• Planning/Prioritizing
• Task Initiation
• Self-Monitoring
• Organization (of materials)
• Emotional Control

The Three Core Executive Functions

The Three “Core EFs”

Common EF (formerly called & still inclusive of “Inhibition”)^1,4,7,8

Working Memory/Updating^1,4,9

Shifting (cognitive flexibility)^1,4,9

According to

• Working Memory^7,1,8
  • Verbal (Phonological Loop) (words, letters, numbers)¹
  • Visuospatial (shapes, patterns, spatial locations)¹
  • Central Executive (attention shifting)¹
  • Maintenance^1,8
  • Manipulation^1,8
  • Updating^1,8
• Common EF, formerly called & still inclusive of “Inhibition”^7,1,8
  • Response Inhibition(behavioral inhibition/self control)^2,7
  • Interference control (cognitive inhibition, selective attention, resisting distractions from irrelevant info in the environment or memory)^7,8
  • “poor common EF is associated with behavioral disinhibition, a general vulnerability factor hypothesized to underlie externalizing behavior problems, such as ADHD, conduct disorder, substance use, and novelty seeking/risk taking” ¹
  • “the ability to actively maintain task goals and use this information to provide top–down support for task-relevant responses”¹
  • There are ‘broad patterns of impairment in EF across most disorders” with similar effect sizes “across the core EF domains” which is consistant with the idea that people with multiple psychopathologies have impairments in the Common EF or teh Executive Attention network.⁴
  • defined similarly as the Executive Attention Network⁴
    
• Cognitive Flexibility(shifting)^1,7
  • goal maintenance (stability)¹
  • shifting (flexibility)¹
  • Simple alternation (10.1017/S1355617704104086)
  • Mental flexibility (same)
  • Perseveration (same)
  • perceptual shift (same)

From these come the “higher-order” EFs, such as:

• Reasoning⁷
• Problem Solving⁷
• Planning^1,2,7–9

Others listed:

• Stopping prepotent or automatic responses⁸
• Switching between task sets⁸
• dual tasking⁸
• monitoring^2,8,9
• verbal and design fluency^1,8
• Word fluency^{10 as quoted in 2}
• organizing²
• behavior initiative²
• thought process flexibility²
• implementation of strategies for problem solving²
• item addition⁹
• active maintenance⁹
• breaking habits¹
• making decisions¹
• evaluate risk¹
• planning for the future¹
• prioritize & sequence our actions¹
• cope with novel situations¹
• item deletion for updating⁹
• Lezak listed 4 components of exec functions:
  • Goal formation^{11 as quoted in 2}
  • planning ^{11 as quoted in 2}
    
  • carrying out goal-directed plans^{11 as quoted in 1,2}
  • effective performance^{11 as quoted in 2}
  • (Lezak added that these behaviors are all necessary for appropriate, socially responsible and effec-tively self-serving adult conduct. As long as executive functions are intact, a person who has sustained consider-able cognitive loss can still continue to be independent and productive (Lezak et al. 2004). -213) ^{11 as quoted in 2}
• It can be hard to really identify these, as many tasks we test probably use multiple EFs/cognitive processes. Things like planning probably use multiple cognitive processes so may not even be a single EF itself. ¹

Executive Functions & Intelligence

Despite some research finding moderate links between certain EFs (such as updating) and intelligence, other EFs, such as inhibition & shifting do not. ¹² Overall, few significant correlations have been found between executive function measures and IQ scores.^{13 as quoted in 2}

• THE 18 EFS FOUND AFTER ANALYSIS³
• Working Memory
  • Efficiency to retrieve words from memory/temporal coding
  • concentration/carry out a sequence of actions
• Strategy generation
  • Conceptualization
  • Maintain set/attentional set formation
• Executive Memory
• Goal Setting
  • Central Executive
• Impulsivity
• Initiation
• Inhibition
  • interference control, control of response, mental control
  • Visual Search
  • Sustained attention or vigilance
• Resistance to distraction
• Problem Solving
• Controlling of Actions
• Plan Development
  • Execute Plan
  • Planning/goal management
• Organization
• Strategy use
  • self-generative behavior/self-monitoring
  • set shifting/selective attention/ shift of attention/attentional control/cue-directed attention
• Cognitive flexibility
• concept formation
• Abstraction
• Fluency
  • response suppression/ response modulation/response generation/control of response
  • verbal efficiency/spontaneous verbal formation
• Sequencing
  • Information processing
• Perseveration
  • Reasoning

Sources:

Executive functions are integral to all aspects of one’s life, including
academic performance & attainment, occupational advancement
& job stability, social functioning, physical health, mental health,
and overall quality of life.¹