This is one of those books that everyone should read. It shows how the internet profoundly changes the way the human brain is wired and discusses theThis is one of those books that everyone should read. It shows how the internet profoundly changes the way the human brain is wired and discusses the possibly resulting cultural and social impacts.
The human brain is an incredibly plastic organ. It can change to adapt to even small shifts in our circumstances and behavior. Particular brain circuits are strengthened through the repetition of mental or physical activities. The reverse of the medal is that if you no longer use certain skills, you gradually forget them. The brain map space dedicated to the activities in question is turned over to the skills you practice instead. The habit of reading, for example, operates profound changes in the brain. Experiments have shown that the brains of the illiterate are different from the brains of the literate. They understand language, process visual signals, reason and form memories in different ways.
The changes that happen within the brain also vary according to the media one uses for reading. Reading a book is very different from reading internet content. The online environment favors cursory reading, superficial learning, as well as hurried and distracted thinking. Even worse, the net deliveries “precisely the kind of sensory and cognitive stimuli – repetitive, interactive, addictive – that have been show to result in strong and rapid alterations in brain circuits and functions.” This prevents us from thinking either deeply or creatively. The changes in brain circuitry are not only profound, but also swift. An experiment performed in 2008 “actually showed people's brains changing in response to internet use.” Using magnetic resonance imaging, scientists observed what happened inside the subjects' brains while they navigated Web pages. As little as five hours on the internet (one hour a day) was shown to be enough to significantly rewire their brains.
The reason why one gradually has his/her abilities to concentrate and think deeply impaired has to do with the way the brain handles memories. There are two different kinds of memory: long-term and working memories. The long-term memory is not some kind of warehouse of information. It is actually the seat of understanding. It not only stores facts and experiences, but also complex concepts (“schemas”). The working memory comprises the contents of one's conscientiousness at any given moment. Nothing is stored in the long-term memory without previously passing through the working memory. “The depth of our intelligence hinges on our ability to transfer information from working memory to long-term memory and weave it into conceptual schemas.”
Unlike the long-term memory, the working memory has a very limited capacity. It seems to be incapable of processing more than two to four elements at a time, “with the actual number probably being at the lower rather than the higher end of this scale.” It is a bottle neck. Give it too much cognitive load (links, pop-ups, animated banners, incoming e-mail message alerts, etc) and it will be overwhelmed, hindering your capacity to learn and retain information. As the author puts it:
When we read a book, the information faucet provides a steady drip, which we can control by the pace of our reading. Through our single-minded concentration on the text, we can transfer all or the most of the information (…) into the long-term memory and forge the rich associations essential to the creation of schemas. With the Net, we face many information faucets, all going full blast. Our little thimble overflows as we rush from one faucet to the next. We're able to transfer only a small portion of the information to long-term memory, and what we do transfer is a jumble of drops from different faucets, not a continuous, coherent stream from one source.
Experiments indicate that as we reach the limits of our working memory, it becomes harder to distinguish relevant information from irrelevant information, signal from noise. We become mindless consumers of data (the emphasis is mine). (…) The division of attention demanded by multimedia further strains our cognitive abilities, diminishing our learning and weakening our understanding.
There is much more to the book than what is summarized above. However, that pretty much gives an idea of the seriousness of the problem, showing why the book is a must read.