Working Memory and Cognitive Load: Why Your Brain Feels So Full.
Imagine you need some things from the shop. You only need 7 items, so you don’t bother to write a list. However, once you are in the shop, you struggle to remember them all, and when you get home, you realise you have forgotten 2 items.
Why does your brain drop off several items like that? Because it has reached or exceeded the limits of its capacity.
This is a common example of working memory being affected by increased cognitive demands.
What does Working Memory do?
Working memory is the part of memory we use to “keep things in mind” long enough to perform complex tasks on them. This could involve analysing, comparing, sorting, sequencing, organising, calculating, and so on.
All humans have limited working memory – it’s estimated that most adults can hold around 4 items at once. This number seems to decrease with age, and in some people with ADHD, the number can be lower to start with, particularly when manipulating information.
Alan Baddeley and Graham Hitch published a landmark paper on a model for Working Memory in 1974, describing 3 main components: the central executive, which acts as a supervisory system and controls the flow of information from and to its subsystems: the phonological loop and the visuo-spatial sketchpad. The phonological loop stores verbal content, whereas the visuo-spatial sketchpad handles visuo-spatial information. Both subsystems only function as short-term storage centres.
You could think of Working Memory as a small workbench where your brain puts things and then moves them around.
How does Cognitive Load feature?
Cognitive Load is how much demand working memory faces at any given moment. The difficulty comes when you try to put too many things on the workbench.
Things that add to the load are, for instance:
Holding onto information while trying to operate on it at the same time.
Hidden decisions: for example, deciding what outfit to wear to work while calculating what others may think of your choices, how comfortable it will be, what the weather is going to do, and whether the boss will be in today.
Holding something in mind over a long period, like someone’s upcoming birthday, with no prompts (unless we create them for ourselves).
What happens when Cognitive Load is too high?
Items can get dropped out, as in the shopping list example above.
You might muddle up the order of a sequence or find it challenging to do that calculation.
And things you knew a moment ago go missing. For instance, while I was writing this article, I had the choosing-an-outfit example in mind one moment, and the next something else occurred to me, and I lost my thought.
Working memory is also shared with attention-switching costs. So if we have lots of things coming in at once and keep switching from one to another, that takes a toll on our working memory as well.
Interruptions are another example of cognitive load spiking beyond our capacity; they often disrupt working memory and push our previous thoughts out of mind.
It isn’t a character flaw or a lack of effort; it’s simply a capacity limit being put under too much demand.
Working Memory and ADHD
- Working memory and attention levels are closely linked. In people with ADHD, there is a higher chance that memories will not get encoded effectively if our attention is elsewhere.
This is how we put things like keys, phones, and credit cards down and lose track of them. Instead of being aware of what we are doing with these important items, our attention is elsewhere, and we automatically put them down without it registering. No attention = no memory encoded.
- Alderson et al. (2013) conducted a meta-analysis of 38 studies of adults with ADHD. They found moderate differences between adults with ADHD and controls in both phonological and visuospatial working memory. The authors concluded that working-memory difficulties persist into adulthood, although they also found that the task methodology influenced whether a difference was detectable.
- Research consistently finds that working-memory performance is, on average, weaker in people with ADHD than in people without ADHD. However, this is a group-level finding: not everyone with ADHD has a working-memory impairment, and the degree of difficulty varies considerably among individuals.
Key points about working memory and cognitive load.
We cannot enlarge the workbench by much (although chunking can help us hold more of certain items in mind); however, we can put less on it.
Three ways we can do this are:
- Reduce the load,
- Offload it somewhere else,
- Cue it using external methods, e.g. triggers and prompts.
Trying harder to remember things won’t work, whereas reducing demand will.
Reliable systems will build confidence, because you’re no longer relying on memory alone.
In Part 2, we look at the tools, hacks, and strategies you can use to build systems that you can rely on to overcome this common phenomenon/support your working memory function.
If you’d like help building systems to help you keep things in mind, reduce cognitive load, or find strategies to support your working memory you can set up a call with Coach Anna HERE.
Coach Anna, PCC, PCAC, has been supporting people with ADHD for the past 12 years, and would love to hear from you. You won’t need a diagnosis in order to begin coaching.