Have you, like me, found yourself turning off the radio when you want to parallel park your car? Or needing everyone to be quiet while you count how many plates of food to dish up?

We would like to argue that we are able to multitask. The reality is though, our brains cannot multitask. Our brains developed to focus on one thing at a time. This focus was needed to keep us safe from dangers in our environment. And although our world looks a whole lot different from thousands of years ago, our brain’s ability to focus on only one thing at a time has not changed.

What we call multitasking is in fact task switching. We switch or change our attention from one task to another task and back again to the first task, again and again. This all happens so fast we think we are doing it at the same time, but it is not true.

The cost of your (in)attention

Each time our brain switches from one thing to the other there are two costs that lead to a drop in our performance of the tasks.

1.     Cognitive costs of task switching

There is a time delay – albeit one that we are not consciously aware of – as we switch from one task to another and refocus our attention. So, even though we think we’re getting a lot done experiments show that we are a lot less efficient.

Furthermore, when we do something, we need to place the elements of that task into our working memory, which is part of our short-term memory. Working memory is actually surprisingly limited and seems to be able to hold about 5 to 7 pieces of information in it at one time.

We refer to this quantity as the cognitive load. When we change focus, we clear the working memory and replace the items with the new task. And then we shift focus again, it is cleared.

This is why we turn down the radio to park a car, ask for quiet to so some sort of calculation, or even to just think.

As an aside, the notion of cognitive load extends from our personal lives into our classrooms. We’d agree, I am sure, that the goal of education is for people to learn skills and knowledge. For us to learn something new, we need to move the new information from short term memory to long term memory.

Not enough time

A number of issues arise here. (Author’s note: I am leaving the idea of schema or cognitive hooks out of this discussion for another time.)

First, there needs to be enough time for this to happen. This means that there needs to be focus for a long enough time for the transfer to happen. If task switching takes place, then there is not enough time for transfer, and obviously the quality of learning will be poor.

Second, we must appreciate that any task has two types of difficulty associated with it. The first is the intrinsic or internal difficulty of a task. Learning to spell though correctly is difficult – this is the intrinsic difficulty. As teachers we prepare our lessons to ensure that we control the level of intrinsic difficulty for success. The second difficulty that a task has is its extrinsic difficulty.

This is how the task is presented and all the things around the task that make it hard to do – you might even think of these as the distractions around the task. Presentation difficulty could include the amount of text on a page or PowerPoint slide and the complexity of a diagram. Other extrinsic difficulties could include noise, the lack of light and even anxiety around the learning situation.

As a teacher, we need to manage the extrinsic difficulties too if we wish to have successful learners.

2.     Metabolic costs of task switching

There is a metabolic cost too. Each time we move our attention from one thing to another we use oxygenated glucose, the stuff that fuels our brains. This brain fuel is needed so we can focus our attention. As you can imagine, using this fuel in all the switching results in an energy drain and we are going to feel exhausted, and even disoriented after all the task switching.

Focusing your attention

Did you do something else while reading this article? Do you perhaps need to go back and read a section again to be sure you remember the key argument?

I think the research is quite clear – when we think we are multitasking, all we are really doing is giving a little bit of attention to lots of things sequentially. And if that is your goal then that is great.

If, however, you want to get some value from the TV episode you are watching, or the newsfeed you are reading, or your friend you are instant messaging – choose one and give it your full attention. Not only will you gain more from the focus, but you are likely to feel less exhausted later too.

In Part 2 we will explore the consequences of distractions –, especially technological distractions – on learning.