A few things to know about cognitive load
In simple terms, the brain has two memory systems: working memory, which is limited and effortful; and long-term memory, which is (near) permanent and easy to access. Here’s a fun way to test the limitations of your working memory:
Tap your foot in a steady rhythm while saying 2+2 is 4, 4+2 is 6, 6+2 is 8, and so forth. How long can you count and still maintain the rhythm?
Now, try the experiment again but say 2×2 is 4, 4×2 is 8, 8×2 is 16, and so forth.
Did you notice how much harder it was to keep a steady rhythm when multiplying? Why is that?
The simple answer is that (for most of us) multiplication tables aren’t as committed to memory as low-number sums. At some point, rather than relying on efficient long-term memory, you had to start calculating with working memory, which is limited and easily overwhelmed. So, a steady rhythm is easy to maintain when most of your working memory is free, but gets harder (or impossible!) when you’re faced with a complex task.
Cognitive load refers to the amount of working memory resources our brain is using at any one time. In the second half of the example, by the time you got to 64 your cognitive load was probably already too high for you to keep tapping. Cognitive load is important to know because (1) we can be easily overwhelmed when our cognitive load is too high, and (2) feeling overwhelmed prevents us from transferring concepts and skills to long-term memory (learning).
Cognitive load theory is concerned with how the limitations of working memory affect learning. It’s a theory that has several implications for educators. First, as you saw from the exercise, we become easily overwhelmed when faced with a new, complex task. Our ability to process information is limited by the constraints of our working memory. However, when we are able to dedicate sufficient working memory resources to a task, we can begin encoding concepts and skills into long-term memory, where they become easy to retain and to access. For example, when you first learned to drive, it probably required all your attention. At that point, it was a complex task and it required a huge cognitive load. But once you got used to it, you found you could drive and talk and probably even listen to music. Now, only when there’s something unusual on the road do you really need to focus. This is because your driving skills slowly got encoded into near effortless long-term memory.
A second implication of cognitive load theory is that if our cognitive load is too high when we’re trying to learn, it hampers the transfer of new schema from working memory to long-term memory. The transfer of concepts and skills to long-term memory is critical because it’s what allows us to get better and faster at increasingly complex tasks. Therefore, if we are to learn (to encode concepts and skills to long-term memory), we must concentrate on the task at hand (germane cognitive load) and reduce irrelevant distractions (extraneous cognitive load) that attract our attention.