About Cognitive Overload - 1
The Factor that Affect Learning 5: Cognitive Overload: 1 of 2
We have come across Cognitive Overload earlier in the book. I wrote about coming home after a very heavy day and having the choice of a difficult book or Hello magazine to read. It was because of my cognitive overload that I chose Hello magazine. The difficult book was too heavy a load for my brain to process.
Cognitive overload has been described by Dylan William, one of the UK’s leading researchers in, and synthesisers about, learning, as ‘the single most important thing for teachers to know.’ It’s a big claim but it is an important one. Dylan William is someone not prone to making outrageous statements about his work. I would only add that it may also be the single most important thing for school leaders, parents and other organisational leaders to know as well.
In this relatively short first of two posts, we’ll try to define exactly what is meant by Cognitive overload.
We have discussed earlier in these posts how the brain uses more energy than any other organ in our body. Because of this, the brain has, over time, developed as an energy conserver. We have seen that this need to conserve energy is one of the main reasons why the brain hardwires repeated experiences. Less energy is used when something becomes ‘automatic’ than when it has to be thought through all the time.
It is really important that we keep in mind that our brain doesn’t have an always on energy source from which to draw. Sometimes we use up the energy the brain needs to work effectively. Cognitive Overload is, firstly, what happens when the tasks that face us require energy that the brain doesn’t have.
We all experience cognitive overload. I don’t want you to think this happens a lot but, a couple of days ago, I was about to come upstairs to write a section of this Substack. Minutes before I did my wife and I had a disagreement that got a little more heated than it should have. As I climbed the stairs, I was full of remorse, running the argument through my head, wondering how it ended like it did and about how my wife was feeling, thinking how I might apologise for my part in it and when would be a good time to do so. By the time I reached the keyboard, my brain had used up much of its available energy and was no longer functioning well enough for me to think about and write the section of the Substack I intended to.
Cognitive overload is very different from simply being distracted. Distraction is a failure to hold my focus. It can be caused by loud music from the next room, the dog barking, an email subject that flashes on my screen and looks more interesting than I should allow it to and so on. With distractions I can, with a little self-discipline, get myself back on track. With distractions, I still have the brain energy to follow them or to control myself and leave them alone.
Meditators know distractions well. Sitting on the mat looking still and focused, the secret of meditation is that meditators’ brains are forever randomly bringing stuff to the forefront of their minds that gets in the way of focusing on the breath. One of the techniques meditators use to re-focus is to note the thought - ‘That was a thought about last night’s concert I went to’ - and then let it float away. Or, as Shunru Suziki once said, ‘Let your thoughts into your brain and let them out again. Don’t just invite them to stay for tea.’ Distractions are part of the experience of meditation.
Cognitive Overload is not a distraction. It’s an inability to process sometimes simple but often complex material because the brain no longer has the energy to do so. We have already emptied our brains’ energy supply before coming to the task in hand. Criminal investigators try and create cognitive overload when they question people for a number of hours at a time. If the suspect is inventing a story, it becomes harder to remember all of the components; as brain energy fades, stories begin to reveal their inconsistencies.
Road rage is often the result of Cognitive Overload. It could, of course, be no more than the actions of someone with a short fuse (although we need to think what having a ‘short fuse’ means) but it often isn’t. The driver of a car, someone who has had a long and difficult day, which they are trying to process, is driving home in the dark, with heavy rain and heavier traffic. They need to be at home at a certain time to see their kids before bed-time (which they haven’t yet managed this week) and are suddenly cut up by a driver squeezing into a too small space because they, too, have had a similar day.
There simply isn’t enough brain energy around to process how to either ignore this relatively minor incident or how to express displeasure with no more than a blast on the car horn. Instead, and before anyone knows it, two people are squaring up to each other. Later, tomorrow morning, after reflection, both may still be cross about the incident but also regretful and slightly embarrassed about their actions. But, at the time….
There is another, related, way in which cognitive overload happens.
In Visible Learning and the Science of How we Learn, John Hattie and Gregory Yates devote a chapter to the impact of cognitive load. It’s not a long chapter but it is one of the best chapters in the book. In this chapter, they highlight a related but slightly different aspect of cognitive overload.
Hattie and Yates point out that working memory is the only type of memory that can be monitored and that everything else appears to be hidden until it is brought into working memory.
The evidence about working memory seems to be that:
We have a working memory that stores around seven bits of information but can work on only between two to four bits at any one time;
Working memory is able to deal with information for a few seconds only. All such information is lost within 20 seconds unless refreshed by the rehearsal process.
Hopefully, as a result of some of our previous posts, you can see the links here between these bullet points and both the brain’s energy needs and the need for repetition (or, as Hattie and Yates call it, the ‘rehearsal process’). Both of these very practical ways in which the brain deals with information have risen out of the brain’s need to save energy.
What is fascinating is that these behaviours only apply to working memory. Our long-term memory - when what we have learned has been laid down as ‘sticky’ - alters what happens. Long-term memory creates ‘big pictures’ or schemas which help reduce the load on working memory, largely because the brain sees the coherent big picture in your long-term memory as one bit to work on and not the hundreds and hundreds of things the big picture actually contains.
Let’s just explore this a little further.
I have spent years reading about, talking about and watching learning happen. For me, my working memory has to work much less hard than someone new to all this learning stuff simply because I have an existing big picture working in the background into which I can integrate any new knowledge and ideas. My brain treats this big picture as one bit of information and, therefore reduces my cognitive load.
A newcomer doesn’t have this big picture yet, although they may be at the start of creating it. For the newcomer, each single input counts as one of the few bits that working memory has the energy to handle. For me, the stickiness of my long term memory big picture alleviates the newcomers learning issues.
Just in case this seems boastful on my part, in many aspects of my life I become the newcomer without a big picture. When, on the day before we do our monthly shop, I look into the kitchen cupboard and see a few individual and largely unconnected items, I have no idea what I could make. My wife, on the other hand, has a big picture or schema about food and is able to create a delicious meal out of something that I just can’t see out of the few things that look separate to me.
It happens to all of us. The important thing is, as Hattie and Yates say, (p147):
Your working memory becomes overwhelmed when dealing with novel or disorganised information. The essential organisation to your knowledge stems from how it is stored in your long-term memory. When organisation is lacking, the mind struggles since the goal is to maintain organisation and reduce load.’
Let’s just summarise this one more time.
First, to perform its tasks, the brain requires more energy than any other organ in the body. Anything that diminishes that energy store diminishes the brain’s capability to do what we would like it to do.
Second, in order to preserve energy, our brains have developed in a way that they can only handle a few small individual items at any one time. Even this small number - one to four - doesn’t get dealt with well unless followed by repetition or the ‘rehearsal process.’
Third, this process is eased if the brain has stored a big picture or schema in its long term memory. That big picture is the result of individual items becoming sticky and then coalescing into an overall schema. The process is made easier because the brain treats the schema or big picture as just one of the one to four things it is capable of handling.
It’s a little like me carrying four things into a room. Three are separate items and I have to balance them very carefully to make sure they are secure. The fourth is a single box which contains inside it a large number of small items. The fourth item still needs carrying carefully but this fourth single item brings inside it many other already connected things.
There are no learning benefits to cognitive overload. It is entirely unhelpful to the process of living and to learning and getting better. The relentless daily life of schools requires significant brain energy. Getting better, as we know, even done well, is a good struggle, moving from somewhere we are relatively secure to a new place that we don’t yet know about. That struggle requires brain energy, too. That’s why Dylan William says the cognitive overload is one of the most important things teachers should know about. Not appreciating cognitive overload only has a downside.
In next week’s post, we’ll look at how this manifests itself for students of different ages, for teachers, for school leaders and for parents. Surprisingly, one of the shorter of our posts about the factors that affect learning turns out to be about something that dealt with badly, can have a huge negative impact.
See you next week.
Martin