When was the last time you sat down in front of a website and read a long piece of writing? And properly read it, without scrolling down, quickly scanning for pertinent sentences or clicking on the first link that looked interesting?
For all its wonderful uses, the internet, as science-fiction writer Cory Doctorow once memorably called it, is "an ecosystem of interruption technologies". But what if the way we read online has a more insidious side effect? What if it is changing the way we actually think?
This was the starting point of a 2008 essay in The Atlantic magazine by blogger, journalist and author Nicholas Carr. He was battling with "an uncomfortable sense that someone, or something, has been tinkering with my brain. Immersing myself in a book or a lengthy article used to be easy. That's rarely the case anymore. Now my concentration often starts to drift after two or three pages. I get fidgety, lose the thread, begin looking for something else to do. I think I know what's going on. I've been spending a lot of time online."
And ironically, most people who read his essay did so online, too. But the response to his ideas - both positive and negative - was so spectacular, he ventured deeper into the subject with best-selling book The Shallows, which earned Carr a nomination for this year's Pulitzer Prize. The paperback publication this summer is likely to ignite the debate all over again. Proof, perhaps, that Carr has touched a nerve.
"A lot of people have found the book disturbing," he says. "And I think that's because it raises concerns about the future that people, in their laudable enthusiasm for the technology, haven't thought carefully about. A lot of people I meet say they had this vague knowledge that something was changing in the way they were thinking, but hadn't understood the full implications or reasons until they read the book."
Through some persuasively readable neuroscience based on the idea that actions repeated again and again change the make-up of our brains, Carr explains that the way we read on the internet actually has an impact on the way the brain functions. By constantly skimming, the brain begins to lose the capacity to process material deeply, which is essential to our critical and analytical faculties, our imagination and most importantly, our ability to acquire and retain knowledge.
Of course, he's not the first person to be concerned about the effect of new technology: Plato was worried that the new-fangled fad of writing would severely affect the art of memory back in 400BC.
"Yes, and I've no doubt we'll survive and adapt to the internet," says Carr. "But I do think the internet is unique in that it's the most intensive media technology that's come along, the first that we carry with us and use all day long. "
The Shallows says that this "always on" culture is dangerous for our minds because it's wholly based on information, rather than knowledge. "Technology has become so good at delivering the precise information that we need at any given moment that we feel we're tapping into knowledge," says Carr. "But knowledge is something we have to build. It consists of the connections we make between the information we have and the experience we have gained, the emotions we feel. It used to be about backing away from the books we'd read and thinking deeply about what we'd learned, but the internet discourages that. It just gives you the most popular answers. It's actually quite worrying how quickly its convenience has begun to push aside ways of research which were central to learning."
The book also contains some intriguing chapters that bounce off Carr's main idea, particularly where he discusses Google's mission "to organise the world's information and make it universally accessible and useful". He also investigates the company's desire to digitise every book ever published.
"A lot of people have huge admiration and trust for the company, and I do have to say, as far as big corporations go, Google is pretty responsible and thoughtful about how it stores and uses information," he argues. "But what worries me is that there's no guarantee that it will be the same in 20 or 30 years' time. Certainly, the people running it won't be the same. So you're placing a whole lot of trust in a company that may change but still has access to all this information."
Carr explains that Google's book projects simply make works of literature "another pile of data to be mined" and moulded to their search tools, rather than actually read. So is there anything he's at all hopeful about in our web-obsessed age?
"Funnily enough, I'm slightly more optimistic than I was when I wrote the book," he laughs. "And that was a most unexpected feeling. There have been a series of other books and articles that look very sceptically and critically at how this technology is having a negative effect on our social and intellectual lives. There are interesting documentaries such as Adam Curtis's All Watched Over by Machines of Loving Grace. It's very difficult for me to know whether all of this is just a rearguard action that isn't going to change how people actually behave. People do seem just as enamoured by Facebook and Twitter as ever. Nevertheless, there seems to be a greater willingness to think about the consequences of living our lives online. Certainly, the discussion has reached a more sophisticated level where we can look at the benefits and the costs."
The upshot is, then, if you've reached this point in the article, well done. The great ecosystem of interruption hasn't snaffled you quite yet.