Call it concentration. Call it flow. Call it focus. Whatever term you want to use for a deep and enjoyable immersion in a single task, experts agree the ability to enter and sustain this mental state is the key to accomplishing exceptional things.

That's probably not news to you. But what might shock you more is new evidence of how far most of us are from this sort of sustained focus at work. Even if you're not one of those who mistakenly believes they can effectively multitask (research-backed news flash: you can't), you're probably abysmal at maintaining concentration.

That's according to research by University of California, Irvine computer sciences professor Gloria Mark, which she recently outlined on Google's re:Work blog.

What can you accomplish in 40 seconds?

Using an array of high-tech gizmos like biosensors to measure stress and cameras to record face-to-face interactions, as well as logs of activity and mood, Mark and her collaborators built up a super detailed picture of how knowledge workers spend our days when we sit down at our computers.

The results? In short, we have the attention span of gnats.

"We have discovered that on average information workers have a very short attention span when working on the computer, with a median duration of focus of just 40 seconds before switching tasks," she writes. Yes, just 40 seconds!

Why is our attention span so short? There's no mystery there -- as you'd guess, most of us are unable to resist the temptation of constant digital distractions, clicking endlessly between email, our main task, social feeds, etc. For instance, study subjects checked their email an average of 74 times a day. (74?!?!) That ridiculous frequency of task shifting led to higher reported levels of stress and lower productivity, of course.

How to fight back and get in the flow

We can all agree that there's absolutely no rational justification for this level of task switching. The only possible explanation is that we're all a bunch of junkies. So how do we fight back against our unhelpful impulses? Mark goes on to offer a handful of helpful tips.

Check out the complete post for her sensible advice such as taking more breaks, working with your natural rhythms of focus and restlessness, mindfulness training, and good, old-fashioned goal setting.

Confess! Do you see yourself in this picture of the constantly distracted knowledge worker?