EXECUTIVE FUNCTIONS AND ADHD

WHAT ARE EXECUTIVE FUNCTIONS?

It is difficult to find an exact definition of executive function deficits. However, they are believed to underlie numerous, if not all, psychiatric disorders in young people and adults (Carr-Fanning, 2012).By their very definition they are the brains ability to regulate itself.

The concept of executive function is neuropsychological in origin, moreover, by definition it refers to the brains ability to regulate itself. In order to function, humans use internal mental processes (e.g., attention, memory, planning, etc.) to adapt to the demands of their environment (Eyesneck& Keane, 2007).

Over the past few decades research into the causative factors in ADHD has blossomed, and our understanding of the neurological basis and the cognitive deficits associated with them has emerged.

ADHD is now attributed to an atypical balance in the neurotransmitters (brain chemicals) responsible for regulating the prefrontal cortex, which is responsible for higher cortical (cognitive) functioning, also known as executive functions. While an exact definition of executive functions is debatable, in general, they are considered to be higher cognitive processes which control an individual’s ability to attend in a persistent way to a task, and organize behaviour in the pursuit of long-term goals (Dawson &Guare, 2004; Hart & Jacobson, 1993; Weyandt, 2005; Willcutt, Doyle, Nigg, Faraone, Pennington, 2005).

EXECUTIVE FUNCTIONS:

1. Working Memory
2. Mental Flexibility
3. Planning
4. Organization
5. Inhibition
6. Attention

Thomas Browns (2004) vividly constructed metaphor provides an illustrative example for executive function defects in those with Attention Deficit Hyperactivity Disorder (ADHD), with their function being likened to or represented as the ‘conductor’ of the “symphony of the brain” (p. 22).

Both the brain and an orchestra contain a number of individual parts which may be viewed as functioning separately. For example, the brain is made up of numerous different systems which operate as semi-autonomous structures, such as memory, attention, emotions, and so forth. Whereas, the former includes processes such as memory, attention, and emotion, while the latter components include drums, violins, and pipes. The conductor of an orchestra is much like executive functions, not in control of how each functions, but responsible for their activation, regulation, and integration as a whole. Brown noted that, “Without a good conductor the symphony will not produce good music …” (2004; p. 23) nor would the brain be able to effectively accomplish tasks.

MODEL OF EXECUTIVE DYSFUNCTION

Russell Barkley (1998, 2006) breaks executive functions down into four areas:

1. Self-regulation of affect, motivation, and arousal
2. Nonverbal working memory
3. Internalization of Speech (verbal working memory)
4. Reconstitution (planning and generativity)

BARKELY’S (1998) MODEL:

1. Self-Regulation
2. Working Memory
3. Internal Monologue
4. Reconstruction

However, he maintains that ADHD is predominantly associated with deficits of response inhibition, also known as self-regulation or self-control.

Thomas Brown (2006) has proffered another influential model which breaks executive functions down into six different “clusters”, which work together in various combinations. Unlike Barkley’s emphasis on self-regulation, Brown does not suggest that one of these clusters characterises ADHD more than any of the others.

1. Organizing, prioritizing and activating for tasks
2. Focusing, sustaining and shifting attention to task
3. Regulating alertness, sustaining effort and processing speed
4. Managing frustration and modulating emotions
5. Utilizing working memory and accessing recall
6. Monitoring and self-regulating action

BROWN’S (2004) MODEL:

1. Activation
2. Focus
3. Effort
4. Emotions
5. Memory
6. Actions

It is important to note here that while the concept of executive functions are interesting and a good body of findings implicate them in ADHD and numerous other condition, their definition, measurement, and role in behaviour and adaptive functioning is complex and not fully understood (Fletch, 1996; Willcutt et al., 2005).

EMOTIONAL DYSREGULATION

A key difference between Brown and Barkley’s models is how they deal with affect, especially emotional dysregulation.

While the DSM-IV does not contain any criteria related to what Paul Wendler (1995) calls “affective lability” (e.g., board or demoralized mood swings, irritability, low frustration tolerance, outbursts of anger, or uncontrollable excitability), it is frequently seen in individuals with the condition. Indeed, some argue for its inclusion as the third core construct of ADHD (Kooji, 2011), alongside ‘hyperactive-impulsive’ and ‘inattentive’.

Discussion does not permit a comprehensive account of these issues, but it is important to note that Brown suggests people with ADHD feel more intensely while Barkley suggests they feel the same as everyone else, but they cannot inhibit their responding to those feelings. Brown acknowledges that response-inhibition is also an issue.

EXECUTIVE FUNCTIONS, SOCIAL COGNITION AND BEHAVIOUR

According to Russell Barkley (1998) observed “ADHD is not a problem of knowing … it’s a problem of doing what you know …” (p. 16).

In the opinion of Zacks and Tversky (2001) “the human mind has a gift for bringing order to chaos …” (p. 3). However, as Hallowell and Ratey (2001) suggest, the ADHD brain is the disorganized brain, possibly explicable, by absent or faulty executive functions or the conductor of the symphony of the brain (Brown, 2004).

It may be that these young people have the knowledge or skills required to function appropriately. However, they may experience significant difficulties in the moment monitoring and interpreting their environment, and also inhibiting emotional responses and selecting the appropriate response in the moment (DuPaul& Stoner, 1994; Tannock, 1996; Young et al., 2005). However, it would explain why children often reporting knowing what the ‘should’ have done upon reflection (e.g., Kinsbourne, 1989).

EXECUTIVE FUNCTIONS IN ACADEMIA

CYP spend a significant amount of their daily functioning in educational settings with teachers and peers (Houghton, 2006).

In order for attainment (i.e., actual learning) to take place, the pupil must possess the intellect, foundation skills (e.g., verbal comprehension is a prerequisite of reading), and behaviours related to academic performance. It is important to distinguish between attainment (acquired knowledge, curriculum criterion mastery, etc.) from achievement, exam results. A comprehensive account of the issues which executive function deficits would play at each of these stages is beyond the scope of discussion, sufficed to say, there are numerous and significant.

Authors of the article: Kate Carr-Fanning and Conor Mc Guckin, the School of Education, Trinity College Dublin, 2012.