IN 2002 America's Defence Advanced Research Projects Agency, best known for developing the internet four decades ago, embarked on a futuristic initiative called Augmented Cognition, or “AugCog”. Commander Dylan Schmorrow, a cognitive scientist with the navy, devised a crown of sensors to monitor activity in the brain such as blood flow and oxygen levels. The idea was that modern warfare requires soldiers to think like never before. They have to do things that require large amounts of information, such as manage drones or oversee a patrol from a remote location. The system can help soldiers make sense of the flood of information streaming in. So if the sensors detect that the wearer's spatial memory is becoming saturated, new information will be sent in a different form, say via an audio alert instead of text. In a trial in 2005 the device achieved a 100% improvement in recall and a 500% increase in working memory.

Is this everybody's future? Probably not. But as the torrent of information increases, it is not surprising that people feel overwhelmed. “There is an immense risk of cognitive overload,” explains Carl Pabo, a molecular biologist who studies cognition. The mind can handle seven pieces of information in its short-term memory and can generally deal with only four concepts or relationships at once. If there is more information to process, or it is especially complex, people become confused.

Moreover, knowledge has become so specialised that it is impossible for any individual to grasp the whole picture. A true understanding of climate change, for instance, requires a knowledge of meteorology, chemistry, economics and law, among many other things. And whereas doctors a century ago were expected to keep up with the entire field of medicine, now they would need to be familiar with about 10,000 diseases, 3,000 drugs and more than 1,000 lab tests. A study in 2004 suggested that in epidemiology alone it would take 21 hours of work a day just to stay current. And as more people around the world become more educated, the flow of knowledge will increase even further. The number of peer-reviewed scientific papers in China alone has increased 14-fold since 1990 (see chart 3).

“What information consumes is rather obvious: it consumes the attention of its recipients,” wrote Herbert Simon, an economist, in 1971. “Hence a wealth of information creates a poverty of attention.” But just as it is machines that are generating most of the data deluge, so they can also be put to work to deal with it. That highlights the role of “information intermediaries”. People rarely deal with raw data but consume them in processed form, once they have been aggregated or winnowed by computers. Indeed, many of the technologies described in this report, from business analytics to recursive machine-learning to visualisation software, exist to make data more digestible for humans.

Some applications have already become so widespread that they are taken for granted. For example, banks use credit scores, based on data about past financial transactions, to judge an applicant's ability to repay a loan. That makes the process less subjective than the say-so of a bank manager. Likewise, landing a plane requires a lot of mental effort, so the process has been largely automated, and both pilots and passengers feel safer. And in health care the trend is towards “evidence-based medicine”, where not only doctors but computers too get involved in diagnosis and treatment.

The dangers of complacency

In the age of big data, algorithms will be doing more of the thinking for people. But that carries risks. The technology is far less reliable than people realise. For every success with big data there are many failures. The inability of banks to understand their risks in the lead-up to the financial crisis is one example. The deficient system used to identify potential terrorists is another.

On Christmas Day last year a Nigerian man, Umar Farouk Abdulmutallab, tried to ignite a hidden bomb as his plane was landing in Detroit. It turned out his father had informed American officials that he posed a threat. His name was entered into a big database of around 550,000 people who potentially posed a security risk. But the database is notoriously flawed. It contains many duplicates, and names are regularly lost during back-ups. The officials had followed all the right procedures, but the system still did not prevent the suspect from boarding the plane.

One big worry is what happens if the technology stops working altogether. This is not a far-fetched idea. In January 2000 the torrent of data pouring into America's National Security Agency (NSA) brought the system to a crashing halt. The agency was “brain-dead” for three-and-a-half days, General Michael Hayden, then its director, said publicly in 2002. “We were dark. Our ability to process information was gone.”

If an intelligence agency can be hit in this way, the chances are that most other users are at even greater risk. Part of the solution will be to pour more resources into improving the performance of existing technologies, not just pursue more innovations. The computer industry went through a similar period of reassessment in 2001-02 when Microsoft and others announced that they were concentrating on making their products much more secure rather than adding new features.

Another concern is energy consumption. Processing huge amounts of data takes a lot of power. “In two to three years we will saturate the electric cables running into the building,” says Alex Szalay at Johns Hopkins University. “The next challenge is how to do the same things as today, but with ten to 100 times less power.”

It is a worry that affects many organisations. The NSA in 2006 came close to exceeding its power supply, which would have blown out its electrical infrastructure. Both Google and Microsoft have had to put some of their huge data centres next to hydroelectric plants to ensure access to enough energy at a reasonable price.

Some people are even questioning whether the scramble for ever more information is a good idea. Nick Bostrom, a philosopher at Oxford University, identifies “information hazards” which result from disseminating information that is likely to cause harm, such as publishing the blueprint for a nuclear bomb or broadcasting news of a race riot that could provoke further violence. “It is said that a little knowledge is a dangerous thing,” he writes. “It is an open question whether more knowledge is safer.” Yet similar concerns have been raised through the ages, and mostly proved overblown.

Knowledge is power

The pursuit of information has been a human preoccupation since knowledge was first recorded. In the 3rd century BC Ptolemy stole every available scroll from passing travellers and ships to stock his great library in Alexandria. After September 11th 2001 the American Defence Department launched a program called “Total Information Awareness” to compile as many data as possible about just about everything—e-mails, phone calls, web searches, shopping transactions, bank records, medical files, travel history and much more. Since 1996 Brewster Kahle, an internet entrepreneur, has been recording all the content on the web as a not-for-profit venture called the “Internet Archive”. It has since expanded to software, films, audio recordings and scanning books.

There has always been more information than people can mentally process. The chasm between the amount of information and man's ability to deal with it may be widening, but that need not be a cause for alarm. “Our sensory and attentional systems are tuned via evolution and experience to be selective,” says Dennis Proffitt, a cognitive psychologist at the University of Virginia. People find patterns to compress information and make it manageable. Even Commander Schmorrow does not think that man will be replaced by robots. “The flexibility of the human to consider as-yet-unforeseen consequences during critical decision-making, go with the gut when problem-solving under uncertainty and other such abstract reasoning behaviours built up over years of experience will not be readily replaced by a computer algorithm,” he says.

The cornucopia of data now available is a resource, similar to other resources in the world and even to technology itself. On their own, resources and technologies are neither good nor bad; it depends on how they are used. In the age of big data, computers will be monitoring more things, making more decisions and even automatically improving their own processes—and man will be left with the same challenges he has always faced. As T.S. Eliot asked: “Where is the wisdom we have lost in knowledge? Where is the knowledge we have lost in information?”