A huge difficulty with research into learning is that learning cannot be observed, only implied from outcomes. What happens in the brain is highly complex and the number of variables involved is huge. The outcomes from research studies can inform you what might work in your classroom, but not necessarily what will work. This is my take on cognitive load theory, but I don’t claim to be an expert.
We live in a very complicated world, constantly bombarded with smells, sights, sounds, tastes and touches. If you stop for a moment and analyse everything that your senses are picking up you will probably notice how little we really notice. To learn something, our working (short-term) memory first needs to separate the ‘signal’ from the ‘noise’ to determine what is important. Usually, this is easier when there are no other distractions like background noise, although even this isn’t as simple as quieter is better. It then tries to make sense of the information before encoding it into our long-term memory. Our long-term memory appears to be unlimited, the bottleneck to infinite knowledge is our working memory.
When we first learn to drive the sheer number of things we have to do can be overwhelming. Synchronising the clutch, gears accelerator and brake as well as steering is a huge cognitive load. For those first steps, it isn’t a good idea to start to learn to drive in Times Square or Central London. Trying to have a conversation with the novice driver is also a really bad idea. As we become experts (over 90% of us think we are better than average) these basic functions become automatic and we can deal with harder driving conditions. Most drivers would still struggle with heavy traffic in unfamiliar areas but experience improves capability. However, confidence can easily outstrip competence.
A model to test the effects of mobile phone use on drivers reaction time showed that in the case of driving towards a pedestrian crossing, the phone use tasks: simple conversation, complex conversation, simple texting and complex texting caused 40%, 95%, 137% and 204% increment in the reaction times.
The increase in reaction times due to the complexity of the communication is probably due to the higher cognitive load, complex testing being the highest.
Cognitive Load is a measure of the amount of mental effort being used by the working memory’ If the working memory becomes overloaded then learning is hampered. We can optimise learning by designing activities that neither overload (confusing) nor underload (boring) working memory.
Here are 2 ways of finding out about cognitive load. A video and a written explanation. Which do you find most effective?
1 – Watch a video
I feel this video explains things well, but I was immediately irritated by the slow speech. It was cognitive underload and I got bored. I increased the playback speed to 1.25 x and was much happier. Try to notice what you are thinking and learning. I regularly focussed on the images rather than listening to her narration and started looking for inconsistencies.
2 – Traditional Blog
Consider a simple model architecture of memory.
Our senses detect stimuli and transfer them to the brain. In the classroom, the information transmitted is usually in the form of auditory and visual data. However, there is evidence that smells can affect memory performance with lavender having an inhibitory effect and rosemary a positive. The vast majority of what we sense is almost instantly forgotten unless it is actively processed by the working memory. This is why it is hard to recall the details of regular journeys to a place of work unless something remarkable occurred. If you now stop for a moment and consider what you can feel, smell, hear, see and taste you will notice how little of our sensory input we really take notice of and memorise.
Single events or learning episodes are often forgotten. Long-term memories are more likely to be encoded and be able to be retrieved if they are rehearsed through drills, repeated practice or ideally through interleaving
Our working memory attempts to categorise and make sense of the information. It creates knowledge structures called schema which are then encoded and stored in the long-term memory. The capacity of the long-term memory appears to be limitless.
A couple of examples of your memory in action
Test 1 Which of these is a blue-ringed octopus?
In order to answer this question, we need to have a schema for blue. The images all have blue parts so we cannot dismiss any of them (I am colourblind hence I cannot create a true schema for blue – they could be purple) If we have a schema for ‘ringed’ we can now discount the one on the left. At an early age, most of us learned about octopuses and created schema for them. Hence we should be able to identify the middle one as the deadly poisonous blue-ringed octopus.
But how big is a blue-ringed octopus? You are unlikely to know unless you have a schema with more knowledge than the basic shapes of octopi. Most of us have an idea that they are football to basketball sizes. The blue-ringed is a tiddler at about the size of a golf ball and having the same mass as a packet of crisps.
If you clicked on the link above to find out more then your octopus schema will now be more detailed than it was before, but not all of the information would be encoded in such a way to allow retrieval. If tested now, tomorrow, in a week and in a year it is likely that the amount you could remember will be diminished unless there is some rehearsal and repetition.
The more knowledge we have about a topic the quicker and more accurately we can make decisions about them.
Test 2 – Spend one minute drawing a bicycle to see what schema you have about bikes.
Most people can accurately draw wheels, saddles and handlebars. Frames pedals, chainsets are a different matter though! There is an interesting series by Gianluca Gimini who creates images of bikes form peoples drawings. See more here
Cognitive load in the classroom
Evidence suggests that working memory can deal with 5 to 9 individual elements at one time. Any more than this we become confused and struggle to remember things. These elements could be 7 random letters or 7 random words, or 7 sentences, or 7 book summaries as long as they have been encoded in a schema. The more we know the more we can deal with at any moment in time.
Test 3 – Where do you reach cognitive overload?
Look at each string of numbers for 30 seconds or less, then look away. Then add 3 to each of the digits in turn.
So if the string was 163 you would do 1+3=4, 6+3 = 9, 3+3 = 6 and the answer is 496
The string 1546 would become 4879
If a number is 7 then 7+3 = 10 then ignore the 1 and make it 0. Similarly, 8 becomes 1 and 9 becomes 2
so 679 becomes 902
So try these one at a time. Write your answers down
3, 16, 973, 3964, 12345, 48251, 555555, 436792, 6753257
You probably found that they became increasingly difficult until 12345 – This counts as only a single element as it is already known. 436792 is much more challenging. Similarly, 555555 is much easier than 436792
Answers to the cognitive load questions
6, 49, 206, 6297, 45678, 71584, 888888, 769025, 9086580
Of crucial importance to educators is that the visual and auditory channels appear to operate separately ie 5-9 of these elements can be processed simultaneously. This means that information presented with both images and sound is much more efficient than just images or sound.
More of how to use this in your classroom in Part 2 – Coming soon