Have you ever tried to follow a recipe while your kids are yelling, the dog is barking, and the smoke alarm is going off? That overwhelming feeling — where your brain just can't handle one more thing — is cognitive overload.
Now imagine being a child in a therapy session, learning something genuinely hard, while also trying to sit still, listen carefully, remember what was said, ignore the noise in the hallway, and work out what the therapist wants you to do.
That's a lot of brain work. And understanding how much "brain work" a child can handle at any given moment is one of the most important things we think about as speech pathologists. Cognitive load theory shapes how we design every therapy session.
What Is Cognitive Load Theory?
Cognitive load theory was developed by educational psychologist John Sweller in the late 1980s, and it's become one of the most influential ideas in education and learning science (Sweller, 2011).
The basic idea is simple: our working memory — the part of the brain that holds and processes information in the moment — has limited capacity. We can only handle so much at once. When the demands on working memory exceed its capacity, learning breaks down.
Think of working memory like a small table. You can fit a few things on it at a time, but if you keep piling things on, stuff starts falling off the edges. Cognitive load theory is about being thoughtful about what goes on that table.
Three Types of Cognitive Load
Sweller identified three types of cognitive load, and understanding them helps us design better learning experiences for children:
1. Intrinsic Load
This is the difficulty that's built into the task itself. Some things are just harder to learn than others, and that's okay.
For example, learning to say the /b/ sound is relatively simple — it involves pressing your lips together. Learning to say the /r/ sound is much more complex — it involves coordinating the tongue, jaw, and airflow in a very precise way. The intrinsic load of /r/ is higher than /b/.
We can't eliminate intrinsic load (the task is what it is), but we can manage it by breaking complex tasks into smaller steps and building up gradually.
2. Extraneous Load
This is the unhelpful "noise" that makes a task harder without adding to the learning. It comes from how information is presented, not from the task itself.
Examples of extraneous load in therapy might include:
- Cluttered, visually busy materials
- Instructions that are too long or complicated
- Background noise or distractions in the room
- Switching between too many different activities
- Unfamiliar or confusing task formats
Extraneous load is the type we want to minimise as much as possible. It uses up precious working memory without helping the child learn.
3. Germane Load
This is the good kind of load — the mental effort that actually contributes to learning. It's the work of understanding, making connections, and building new knowledge.
When a child is concentrating hard on forming a new sound, figuring out a grammar rule, or working out how to structure a sentence — that's germane load. We want to protect and support this kind of thinking by reducing everything else that's competing for brain space.
Why Does This Matter in Speech Therapy?
Children who come to speech pathology are, by definition, working on skills that are challenging for them. They're already carrying a higher intrinsic load than their peers for many communication tasks.
On top of that, they might be dealing with:
- Anxiety about getting things wrong
- Sensory sensitivities that make the environment overwhelming
- Fatigue from working hard all day at school
All of these add to the total cognitive load a child is carrying. If we're not careful about managing that load, we can push children past their capacity — and that's when learning stops.
Gillam and Gillam's work on applying cognitive load theory to language intervention has been particularly influential in our field. They argue that speech pathologists need to carefully consider the cognitive demands of every aspect of a therapy task — not just the language target itself, but the instructions, the materials, the social demands, and the task format (Gillam & Gillam, 2014).
How Cognitive Overload Shows Up in Sessions
Children don't usually say, "Excuse me, I'm experiencing cognitive overload." Instead, they show us through their behaviour. Here are some common signs:
- Shutting down — going quiet, looking away, becoming passive or withdrawn
- Frustration and upset — getting angry, crying, saying "I can't do it" or "This is stupid"
- Increased errors — making mistakes on things they could previously do well
It's really important to recognise that these behaviours are often signs of overload, not defiance or laziness. A child who refuses to try isn't necessarily being difficult — they may be telling us that we've asked for too much at once. When I've worked with children who are quietly overloaded, the smallest changes — a shorter instruction, fewer things on the table — often make the biggest difference.
The Goldilocks Zone
The goal in therapy (and in learning generally) is to find the sweet spot — what some educators call the "zone of proximal development" — where the task is challenging enough to promote growth, but not so demanding that the child's working memory is overwhelmed.
This zone is different for every child, and it changes from day to day depending on how they're feeling, how much sleep they've had, what's happened at school, and dozens of other factors. A good therapist is constantly reading the child's cues and adjusting the demands of the task to keep them in that productive zone — which is part of why we move fluidly between child-led and clinician-led approaches within the same session.
What Does This Mean for Parents?
Understanding cognitive load can change the way you think about your child's learning:
- If your child melts down during homework, it might not be a behaviour problem — they might be overloaded
- If your child can do something in therapy but not at home, the cognitive demands of the home environment might be different (more distractions, less support, end-of-day fatigue)
- If your child seems to "forget" skills they've already learned, they might be carrying too much load for those skills to be accessible right now
In our companion article, we'll explore practical strategies for reducing cognitive load — both in therapy sessions and at home.
If you're noticing signs of overload in your child, or you'd like to understand how we manage cognitive demands in therapy, we'd love to talk it through.
Ready for practical strategies? Read our companion article: Reducing Cognitive Load in Therapy: Strategies for Better Learning | Brisbane
Alexandra Bouwmeester is a Senior Speech Pathologist (MSPA, CPSP) with a research-informed approach and over 14 years' experience. She designs learning-friendly sessions for children across Brisbane's south side and Logan.
References
Gillam, S. L., & Gillam, R. B. (2014). Improving clinical services: Be aware of fuzzy connections between principles and practices. Language, Speech, and Hearing Services in Schools, 45(2), 137–144.
Sweller, J. (2011). Cognitive load theory. In J. Mestre & B. Ross (Eds.), The Psychology of Learning and Motivation (Vol. 55, pp. 37–76). Academic Press.
Sweller, J., van Merriënboer, J. J. G., & Paas, F. (2019). Cognitive architecture and instructional design: 20 years later. Educational Psychology Review, 31(2), 261–292.
