Why Executive Functions Seem to Come and Go
"They did it yesterday."
"They know how to do it."
"They can focus when they want to."
These are some of the most common statements I hear from parents, educators, and professionals working with neurodivergent children and young people.
When executive function abilities appear inconsistent, it's easy to assume the person is choosing not to use them at time. It can look like a motivation problem, a behaviour issue, or even laziness.
But in many cases, the executive function ability itself may not be the sole factor. The barrier may also be the individual’s capacity to access their executive functions in that moment, with both ability and capacity influencing performance.
Executive Function Is Not Just About Ability
Executive functions are a set of cognitive abilities that help us plan, organise, start tasks, manage emotions, shift attention, remember information, and monitor our behaviour. Traditionally, we think about executive functions as a set of abilities that can be learnt and practised. In this view, if we learn new skills and practice them enough, we should be able to use them when we need.
While this is true, there is another important factor that is often overlooked when thinking about executive functioning; Our capacity to access executive functions in the moment. We may have the ability, but not always the capacity to access it.
Think about a child who can pack their school bag independently on some mornings, yet seems completely unable to do it on others. Or a teenager who can use a planning strategy beautifully during therapy sessions but struggles to apply it at school. Or an adult who manages a busy workload one week, and feels completely overwhelmed the next.
In many cases, the executive function ability itself may not be fluctuating. Instead, the person's capacity to access and use those skills in the moment may be changing.
Why Capacity Changes
There are three main reasons why our capacity to access executive function abilities may fluctuate:
1. Stress and Sleep
Executive functions rely heavily on networks involving the prefrontal cortex. These networks are closely connected with other brain systems involved in emotion, stress, alertness, and survival, or those “instinctive” areas of our brain. When these instinctive areas of our brain sense disruption, the brain might go into survival mode (i.e., “fight, flight, or freeze”). And when in survival mode, the brain prioritises automatically responding to those immediate demands.
By prioritising an automatic response this lowers the brain’s capacity to access other areas of the brain. And given the prefrontal cortex has direct connections to these instinctive parts of the brain, this makes executive functioning very sensitive to changes in stress, emotions, alertness, and other threats to survival.
In everyday life, this may present as child who can usually follow a morning routine independently, but who may suddenly need frequent reminders after several nights of poor sleep.
2. Motivation and Interest
Capacity can also fluctuate due to motivation and interest. For some neurodivergent individuals, particularly many people with ADHD, motivation plays a significant role in executive functioning. ADHD researcher Dr William Dodson describes ADHD as an 'interest-based nervous system', where engagement is often influenced more strongly by interest, novelty, challenge, or urgency than by importance alone.
So when a child struggles to begin cleaning their room, it could reflect weaknesses in planning and organisation, however, for this (boring) task, a lack of motivation may also be a large barrier to starting. A good way to check if motivation is the main barrier, is to make the task more interesting (can they clean their room while creating a time lapse video?).
3. Sensory overwhelm
Many neurodivergent individuals are also managing significant sensory demands throughout the day. Processing noise, movement, bright lights, busy environments, clothing discomfort, social interactions, and constant transitions requires mental effort. When the brain is using substantial resources to manage sensory information, fewer resources may be available for executive functioning.
For example, a child may appear capable of organising themselves well at home, but struggle after spending a full day navigating a noisy classroom, bright lights, social demands, and multiple transitions. The executive function challenge may not be a lack of skill, but the cumulative impact of sensory and cognitive fatigue.
When we understand these influences on executive functioning, a different picture emerges. A child who struggles today may not have lost the skill they demonstrated yesterday. Instead, they may have less capacity available to access that skill. Recognising this difference helps us move from asking 'Why won't they do it?' to asking 'What might be getting in the way right now?'"
Ability or Capacity? A Helpful Question to Ask
One useful way to determine whether a challenge in completing tasks is related to ability or capacity is to address the factors of stress, sleep, motivation, and/or sensory overwhelm, and observe if anything changes.
If the person can access the executive function ability when additional supports are provided, capacity may have been the primary barrier. And if they do have lower capacity in some environments, that’s a great clue that we may need to increase the scaffolding support around their executive functioning.
For example:
A teenager has learnt how to plan and organise their homework. During the busy end of term period, they start sleeping later, stressing about upcoming exams, and all the organisational systems fall by the wayside. Instead of assuming they have slipped backwards in their organisational abilities, they are supported to increase their sleep, use strategies for stress, and to ask for adult input when feeling overwhelmed. Within a couple of weeks, they are back to using their planning and organisational system for homework.
The ability to plan and organise appeared to be present. What seemed to be limiting their performance was the teens capacity to access and consistently use that ability at the time.
A child is able to get ready independently for sport on weekends by 8am, but struggles to leave the house on time for school during the week. When they work with an adult to highlight what motivates them each day to attend school (a morning downball game with their mates before class!), they require significantly less prompting from parents.
Again, the issue may not have been a lack of ability. It was more likely to have been the impact of low motivation for a non-preferred task, inhibiting their ability to engage their executive function abilities.
Supporting Executive Functioning in Everyday Life
When executive function difficulties arise, it can be useful to both support the executive function skills required for the task AND to check and support their capacity to engage their executive functions at that particular time.
To support their capacity, strategies may include:
Reducing environmental distractions
Providing visual supports and reminders
Breaking tasks into smaller steps
Building in movement or sensory regulation breaks
Connecting tasks to personal interests and motivation
Adjusting expectations during periods of stress or fatigue
Supporting emotional regulation before demanding executive function
A Different Way of Understanding Executive Function
For many families and professionals, learning that executive functioning does not operate in isolation from other parts of the brain, and that executive functioning can fluctuate with capacity can be one of life’s great “a-ha” moments.
Understanding that both executive function ability and capacity to access these skills can both impact performance, helps explain why someone can demonstrate an ability one day and struggle with it the next. It moves us away from assumptions about effort and toward a more compassionate and supportive understanding of what is happening.
Where to Next?
If you'd like to learn more about the role motivation plays in executive functioning, explore our new “PINCH for motivation” resource in the Dandelion Hub Resource Library.
If you’d like to learn more about the impact of stress on the brain, watch this super short video by Dr. Dan Seigal as he explains how our brains “flip the lid” when stressed.
______________________________________________
Written by: Dr. Ruth Tesselaar, Neuropsychologist and Founder of Dandelion Hub