I’m Nick Hunt-Davis. I’m writing down some of the things I think and say about brains and machines and how to make them best buddies. This is what I do all day at Convious as head UX honcho.

— — — —

“Cognitive fatigue” A very impressive sounding UX buzzword.
It’s right up there with “Gamification” and “Growth Hacking”.

Cognitive fatigue means something very real, despite its relentless misappropriation by designers and product owners around the galaxy (I assume).

What is Cognitive Fatigue?

Your brain is the most intricately complex thing in the universe! It is capable of processing fully-realised, high-definition, 4d visuals, it grants you superpowers like echolocation, time manipulation and memory storage greater than every hard drive on the planet. Your brain does this all day, every day, casually.

It’s hungry work for your brain! He consumes about 20% of your total energy spend. That leaves just 80% for walking, talking, breathing, jumping, sexing, designing, coding and everything else (All of which are managed by your brain anyway). He’s a super-duper busy guy.

He gets tired.
You’ve all felt it.

Cognitive fatigue is what happens when your thinking bits get tired.

There’s only so much he can comfortably do in a day.

Every morning your brain wakes up with a set and finite number of “F**ks to give”. As he goes about his brainy day, doing different brainy things, he spends some of his “f**ks to give” allowance. It’s exhausting.

Not every action takes the same toll on your poor brain mind you. Most of his daily activities are automatic, and your brain completes these tasks as easily as we sit through 14 hours of Game of Thrones.

It’s the manual tasks that get the little guy really tuckered out.

Manual vs. Automatic thought.

Automatic actions don’t really cost him any “F**ks”. He can do that stuff blindfolded, it almost happens on its own.

Here, I’ll prove it.
What’s 2 + 2 = ?

Easy right? You already knew that one. No real thinking required. This is an automatic brain action that requires a very little cognitive load. Answering 2 + 2 results in practically no cognitive fatigue at all.

Okay, how about 13 x 27 = ?

You could answer that last one sure (maybe), but without a calculator, it’s not quick. It certainly isn’t automatic. You’d have to really engage the thinker. You’d have to spend a few f**ks. Your hear-rate increases, your pupils dilate, you burn extra calories (that’s right! Thinking hard burns calories!) and you’d have to chip away at today’s limited f**k quota.

The harder the problem, the more f**ks you have to spend to solve them.

Even relatively easy tasks like choosing which outfit to wear have a small cost. It’s why Mark Zuckerberg wears that same miserable grey t-shirt every day. That way he gives his brain a little breather so it can work harder on commoditising people later on.

Turning the Manual into the Automatic

This is probably your brain’s most incredible trick! Your brain can totally turn manual tasks into automatic ones! And it does this on its own.

Think back to a time when you were driving in your car, going somewhere familiar (like your daily commute), nodding to some sweet tunes, enjoying the wind through your hair and the glorious sunshine tanning one arm to bronzed perfection — you suddenly realise you have no idea how you got where you are! I mean, you know that you drove there, but you can’t recall in any level of detail the past few kilometres of driving! Turns, dodging taxis, navigating broken traffic lights — a whole mess of complicated decisions that your brain made without your conscious consent. Naughty brain.

Now think back to when you first learned to drive. Remember how difficult it was? Operating a giant, combustion-engine-powered-exoskeleton isn’t easy in the beginning. It takes a lot of manual thought and concentration to not stall in front of all the pretty girls (or boys).

Today though, after years of driving. All of that complication has become so second nature, so automatic, that you can literally drive across town without being actively aware of most of what you’re doing. The very same things that were so difficult at first, have become effortless.

Our brains, through repeated action, are able to turn a manual thought process into an automatic one.

Aren’t we clever! (Our brains at least)

“Nick! If you do the dishes every day, it stops being a chore and then it’s just a weird thing that your body does while you think of other stuff.”
– Jess Jardim-Wedephol (Dear friend and once-upon-a-time housemate)

That’s probably not exactly what she said, I don’t remember verbatim. It was probably something like that, but a little dorkier.

But she’s absolutely right.

So how can we harness this to improve interaction design?

Jolly good question!
In my next article, I’ll discuss some practical examples and ideas for creating habit-forming design patterns. Turning manual interaction, into automatic ones. I’ll even teach you a trick on where switching from automatic interaction to manual can enhance your user experience.