Cognitive load and cognitive offloading

I’ve stated elsewhere that working memory is limited and that these limitations can hamper our ability to learn new things and carry out complex tasks. I’m implying here that learning and remembering are either the same or very similar, so I’m referring to learning in a rather narrow way, but stay with me on this.

Let’s take an example that’s perhaps more about memorising than any expanded conception of learning; remembering a telephone number. I used to have an office job when I was young that involved lots of telephone conversations, most of them brief because, more often than not, all I was doing was taking messages for other people in the organisation. Most of the time I was given a phone number to pass on to one of my superiors. Now, I could have tried to hold the phone number in my working memory and rehearsed it until I could recite it by heart, but this probably wouldn’t have been a particularly productive use of my time. An added complication would have been that if I was given more telephone numbers to memorise, this would further increase the load on my memory and would, no doubt, interfere with the previous and subsequent numbers and messages. Forgetting would, therefore, be either a process of interference or of temporal decay, depending on where you place yourself in this particular debate.

So what could I do to mitigate these high demands on my working memory? The answer is ridiculously simple; I would write the number down and get on with my work. Now the only thing I had to remember was to pass the number on to whomever it was intended. Telephone numbers are a particularly interesting case. I grew up in world without Smartphones; even without landlines that could store phone numbers, so I generally had to memorise a few numbers just to get by. Today, I barely know any. Technology has changed the way we remember many things and we tend to store more information, not in our heads, but on some kind of external device.

Let’s look at another example. When I go shopping I always try to make a list of all the things I need. I find there’s something about supermarkets that make me forget what I needed the moment I pass through the sliding doors (there’s actually a cognitive explanation for this; a future blog post, perhaps). The shopping list is just like the telephone number I wrote down in the previous example. There are, of course, many techniques I could try to remember the shopping list, but why put myself through all that if I could just write all the items down and get on with something else more interesting than rehearsing strings of shopping items.

Messages, shopping lists, reminders, notes and a whole host of other behaviours have been given the name cognitive offloading by psychologists. There are many things in the world that we don’t need to commit to memory, even though we might want to. If you’re a competitor in the World Memory Championship you will certainly want to spend a great deal of your time investigating ways to remember list of words, digits, suits in decks of cards or the value of pi to goodness’ knows how many decimal places. However, the practical implications of being able to do this are limited. As learners, we certainly need to commit some things to memory, yet it’s also useful for us to be able to decide when it’s advantageous to offload this information. Cognitive offloading represents a very simple way to circumvent the limitations imposed on us by our short-term memory. Anything that we hold in working memory can be written down. Similarly, we can use applications to save important dates. We can even set a reminder so that we don’t miss an appointment, a birthday or anniversary.

Who offloads?

But are some people more likely to offload than others? One might assume that people with lower working memory capacity would choose to offload more than those who seem able to hold more information in working memory (their individual working memory capacity). Working memory capacity is often measured subjectively, so we would rely on a participant in an experiment deciding when their higher capacity had been reached. We would assume, therefore, that lower subjective memory ability would lead to higher levels of offloading behaviour, and this does seem to be the case (Gilbert, 2015). We can see this in studies where participants are told not to offload in one condition but have the choice to offload in a second condition; those individuals who displayed higher subjective working memory capacity tended to offload less when given the option (Risko and Dunn, 2015). Our ability to decide when we need to offload is an important metacognitive strategy.

Not surprisingly then, people are more likely to offload as working memory load increases. This means that there is often a time dimension – you probably won’t offload at the start of the task, but as the task increases the load on working memory, you may well choose to do so. But people also offload as attentional resources are reduced. Say you’re trying to memorise a telephone number and someone starts a conversation with you. We know from decades of research that splitting our attention in this way is going to reduce the effectiveness of both tasks: you can keep rehearsing the telephone number or engage in the conversation, but you can’t do both! The best thing to do in this situation would be to write down the telephone number and then have the conversation. However, people may also offload when they don’t need to. This final point is potentially important when we begin to consider the downside of offloading. 

The curious downside of offloading

The benefits of offloading seem simple, but there are also some curious downsides. For example, in a 2011 study, participants who thought they would have access to the learned information later, showed poorer memory for them (Sparrow, Liu & Wenger). This is related to another phenomenon, whereby memory for test items increases when participants are told that they’ll be tested sometime in the future.

This phenomenon had also been found in memory for visual items, such as photographs. In a 2014 paper, Linda Henkel identified the photo-taking impairment effect whereby people who took photographs of items displayed poorer memory for those items later than people who were asked simply to observe the items. It could be that those who took the photographs believed that they didn’t need to remember the items because the camera would do it for them. However, the photo-taking impairment effect was also observed when people didn’t believe they would have access to the photographs later (Soares & Storm, 2017). The authors of the study have suggested that engaging in photo-taking might disrupt the normal cognitive processes of encoding object features, however they admit that more research is needed.

In conclusion, offloading generally benefits performance but can also lead to impairments when the offloaded information isn’t available at the time it’s needed (i.e. if you don’t have your lecture notes when you’re being quizzed, there’s a greater chance you won’t be able to recall the information). Offloading in more likely to occur in people reporting lower subjective working memory capacity coupled with higher cognitive demands (if you believe your working memory capacity is poor, you’ll be more likely to offload). However, we must bear in mind that research into cognitive offloading is still at an early stage, with most studies concentrating on cognitive load without offloading (e.g. in relation to Cognitive Load Theory). Nevertheless, the view that people always need to commit things to memory isn’t compatible with what they actually do in their daily lives, such as writing shopping lists, storing telephone numbers on their devises and jotting down notes. 

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