The Shallows: What the Internet is Doing to Our Brains, By Nicholas Carr

Even if internet usage is rewiring our brains, is it necessarily a threat to all human culture?

When Nicholas Carr begins his new book – a dissection of the internet's effect on the modern mind – by bringing up Socrates, you can read his naked ambition. This will not be another survey of the megalith that is Google or an investigation of the breakdown of social relationships since the advent of Facebook. No, Carr is going to write about all human knowledge in a mere 300 pages.

The headline-grabbing concept of The Shallows is that the internet is rewiring our brains to negative effect. Carr recognises that he is placing himself in a proud tradition of Jeremiahs bemoaning technological advancements, from Socrates, who fretted that the written word would create "forgetfulness", via the Gutenberg press naysayers, to those who were disturbed by the unfettering of the written word, the speed of the telegram, and finally the internet, a vast, seething jungle of distraction and inanity.

His argument is twofold. The first, and less interesting part concerns the neuroscientific aspect of the problem. He begins by restating the media theorist Marshall McLuhan's mantra, "The medium is the message", as a prelude to a lengthy analysis of how we react differently to words on the web from those in a book.

Central to this is an experiment by the American psychologist Gary Small, who took a group of people who hadn't used the internet before and found that spending a week on the web triggered major activity in the dorsalateral prefrontal cortex, an area which is regarded as the decision-making and problem-solving part of the brain.

But, of course, that is the internet for you. Inherent in using it is the art of making snap choices about which link to follow, which email to read, which person to follow on Twitter, and the feeling of satisfaction of locating information fast. Carr concedes that this decision-making is a part of keeping the human mind sharp. But what concerns him is that, while the dorsalateral prefrontal cortex is in a frenzy of electrical pulses, other parts of the brain go into abeyance. In particular, the areas involved in the consolidation of thoughts and their transfer into long-term memory.

Evidence for this conjecture turns out to be rather thin, at which point Carr deftly moves away from neuroscience and into a more interesting argument regarding our communal understanding of culture. All that internet browsing has reduced our ability to concentrate on long-form reading, and the greatest victim has been the book. Carr is not merely talking about dumbing down. What he posits is more significant: that human culture has been built steadily over our literate history by deep and meditative reading, and the internet threatens to undo this process.

Many of us, for instance, have read War and Peace in a calm and meditative state, and absorbed not only the words and information but also the ideas and significances, and transferred those into our long-term memory. As such, each of us carries part of the weight of human culture in our minds. Should we abandon the book, we would also abandon this collective knowledge, leaving it to be arbitrarily outsourced to Google searches and Wikipedia.

Carr is also deeply wedded to the predominance of the single linear thought that is represented by the book – a closed form without hyperlinks, bright flashing adverts and email distractions. He recalls Steven Johnson's brilliant line in Everything Bad is Good For You that reading a book "understimulates the senses", and argues that this is a good thing.

But what Johnson actually wrote in Everything Bad... pre-empts Carr. Johnson found that the human brain can deal with far more than a mere linear narrative and has a natural hunger for complex thought, from the intricate political and cultural references in The Simpsons to the expansiveness of networked computer games. Witness, also, the phenomenon of The Wire. It was not a book, but was frequently referred to as Dickensian, required an extended attention span, and has been committed to our culture as a 21st-century reference point. It could hardly be called shallow or easily forgotten.

All this happened alongside the internet. While we know how to ride the blizzard of information, conversely we also still seem to have the capacity to sit back, think slow, and participate in richly connected intellectual environments.

Our brain wants more, our culture delivers more. And as for the death of the book, Carr might like to note the news from Amazon this summer that downloads of ebooks have outstripped sales of the hardback. Digital reading, it seems, doesn't have to be bitesized.