ThinkingYour ability to focus: a limited mental resource

Your ability to focus: a limited mental resource

Psychologists increasingly think that your “executive function” – the part of you that makes decisions and maintains actions – depends on a limited resource. Your ability to do important things, like focus on a task, depends on a certain amount of mental strength or energy. And, it would seem, just like physical strength and energy, you can deplete that resource: eroding your ability to focus.

A great study by Kathleen Vohs and others, in the August 2014 edition of Motivation Science, presents a number of experiments that show how executive function – your ability to maintain focus and exercise self control – can be depleted. Experiment 3 in that paper looked at a group of college students who were asked to think about future choices for their college study. One group was asked to go to the effort of making decisions about their future study, while the control group simply got to read course descriptions. Both groups then were given 15 minutes to prepare for a non-verbal intelligence (maths) test that they were told they would be sitting. They were told this test is a great predictor of future real-world success and that preparing for 15 minutes beforehand (but not more) was shown to be a significant way of improving performance. At that point they were left with practice materials for that test.

Interestingly, the control group – the ones who hadn’t had to make any decisions – studied for that maths test for an average of 11.40 minutes. The other group – the group that had had to make decisions about future course study – only prepared for 8.39 minutes – a performance decline of 26%.

In other words – the group that had been forced to use mental energy (“depleted their executive function resource”) by making decisions then had less mental energy to focus on preparation for the maths test. In the words of the authors:

“Making choices can lead to a breakdown of self-control”.

Or, the energy used to make decisions is then not available to be used to help maintain focus on a subsequent important task.

In simple terms – you only have so much mental energy available in any given day – if you use it on one task it won’t be available for another.

So, how do you make sure you have enough mental energy for the important things? Here are five ideas for maximising your mental energy:

1. Get enough sleep

Obvious but true. If you are well rested you will have more mental energy for the day. This is worth a blog post on its own. But let’s just say this for now: sleep is increasingly seen as being a vital factor in a person’s success.

You would remember the “10,000 hour rule” popularised by Malcolm Gladwell. That was based on a study by K Anders Ericsson of famous violinists. That study found that the biggest predictor of success was the amount of time practicing. But guess what the second biggest predictor of success was? Yep – time spent sleeping – the more time spent sleeping the better violinist they were. (For a discussion on this, see Greg McKeown’s great book “Essentialism“, Crown Business, 2014, p 97).

2. Prioritise your most important tasks

If your ability to focus is driven by a limited resource of mental energy, make sure you attend to your most important things first in your day. If you have to get that paper written for your boss, get it done early on. And, conversely, if you have had to spend all day in a strategy workshop making decisions for your business – don’t expect that you will have the mental energy at the end of the day to be able to focus on hard stuff. Give yourself the evening off!

3. Email is the enemy

As always, email is likely to be an enemy of focus. Not just because of the distraction it causes. But also, because every time you attend to an email you have to make a decision about it: do I do it now; do I delegate it; do I dump it; or, when will I do it? That decision making – let alone any decisions the email itself is requiring of you, will deplete the mental resources that support your executive function.

Remember – email is a great mechanism for responding to other people’s priorities, not your own! So, do your email after you’ve done your key tasks requiring your best focus.

4. Minimise extraneous decisions in your life

Your brain will try to make as many decisions as you present it with. And it will use energy equally on important decisions and unimportant ones. If you use up energy on unimportant decisions, it isn’t going to be there for focus when you need it.

Daniel J Levitin, in his book “The Organised Mind” (Dutton, 2014), puts it well (p6):

“One of the most useful findings in recent neuroscience could be summed up as: The decision making network in our brain doesn’t prioritise.”

As a result, look for ways to not have to make extraneous decisions in your day. Can you get a routine going in the morning so you don’t have to think? Can you delay decisions on trivial stuff to the end of the day?

5. Use tools to help you focus

Acknowledge that focusing on a piece of work will take effort – so look for ways to make that focusing easier. For me, one of the best ways is to think with pen and paper. Always write down your thoughts. Map them out using a Rico cluster. Do anything to minimise the effort your brain requires to keep information in working memory.

Additionally, if you are focusing on one thing and you think of something unrelated – like having to pick up the dry cleaning later today – then have pen and paper ready to write that down. That way your brain gets it out and you can go back to focusing on the task at hand. Mental energy saved!


Let me know if you have any tips for how you preserve mental energy for the demanding tasks in your day. Leave a comment below. Also, if you are enjoying these posts please subscribe to this blog using the blue button on the top right of this page.