Multitasking may be ubiquitous in today's plugged in, multidevice world, but you've probably already heard that not everyone thinks just because you can do multiple things at once that you actually should.

Doctors at Harvard, we've reported, declared war on the practice when a resident nearly killed a patient after a text message distracted her from updating a prescription. Authors Maggie Jackson and Nicholas Carr have both written books and blog posts about the bad things computer-assisted distraction is doing to our brains.

But even if you're familiar with the multitasking backlash, a figure unearthed by blogger Eric Barker will probably shock you. He recently read Your Brain at Work: Strategies for Overcoming Distraction, Regaining Focus, and Working Smarter All Day Long, by David Rock, and pulled out a truly horrifying study finding to share in a post. Brace yourself:

"A study done at the University of London found that constant emailing and text-messaging reduces mental capability by an average of 10 points on an IQ test. It was five points for women, and fifteen points for men. This effect is similar to missing a night's sleep. For men, it’s around three times more than the effect of smoking cannabis. While this fact might make an interesting dinner party topic, it's really not that amusing that one of the most common "productivity tools" can make one as dumb as a stoner."

That means when you're switching between answering emails and doing important tasks for your business, when it comes to mental function, you'd be better off if you were stoned. Or, as another quote from the book highlighted by Barker puts it, "when people do two cognitive tasks at once, their cognitive capacity can drop from that of a Harvard MBA to that of an 8-year-old."

Are you ready to put down the smartphone yet? If you're still clinging desperately to your device and looking for support, be advised that not absolutely everyone has jumped on the anti-multitasking bandwagon. Writing for the HBR blog network, professor Tom Davenport argues that people have been fretting about "information overload" for decades but have never and will never do anything about it. He asks:

"So if information overload is such a problem, why don't we do something about it? We could if we wanted to. How many of us bother to tune our spam filters? How many of us turn off the little evanescent window in Outlook that tells us we have a new email? Who signs off of social media because there's just too much junk? Who turns off their BlackBerry or iPhone in meetings to ensure no distractions? Nobody, that's who -- or very few souls anyway."

And he decides that, though scientists may prove multitasking is harmful due to our never-ending desire for the new, our "information inertia," and our tendency to undervalue our own attention, we'll never do anything to stop. So stop fretting about it.

"Next time you hear someone talking or read someone writing about information overload, save your own attention and tune that person out. Nobody's ever going to do anything about this so-called problem, so don't overload your own brain by wrestling with the issue," he concludes.

Does Davenport make you feel that it's OK if you're unable to put down your phone, or will the finding that multitasking reduces your intellect to stoner levels inspire you to change?