Over-loaded brains and shorter attention-spans

Did you know that on average 130,000 new books are published every year in the UK (190,000 in the US), that around 20gb of video is uploaded to the Internet every minute and that a week's worth of the New York Times contains more information than a person was likely to come across in a lifetime in the 18th Century.

Through emails, telephone, texting, social networking, reading, the radio and other media, it is estimated that the average person living in the western world sees or hears around 100,000 words per day. Indeed, the University of California, San Diego, estimate that during the last 30 years the total number of words we "consumed" has more than doubled. In the US this has gone from 4,500 trillion in 1980 to 10,845 trillion in 2008.

If you look at the data relating to the total amount of information that exists rather than simply at that which we see of hear, the figures are even more frightening. The same team at the University of California estimate that by the end of 1999 the sum of human-produced information (including all audio, video recordings, text/books and every word ever spoken) was equivalent about 12 exabytes of data, where 1 exabyte equals 1 billion gigabytes, but that today 4 exabytes of data is added to the Internet each year!

The figures are just as impressive as the technology that makes it all possible, but what effect is this deluge of information having on us, our brains and the way we behave?

The neuroscientist Baroness Susan Greenfield has expressed serious concerns. Her point is that due to the phenomenon known as 'plasticity', every experience you are exposed to causes your brain to modify itself. If that experience is changing, it follows that the brain will adapt in responses. Since the changes that have come about as a result of the computer revolution are so profound, it is not unreasonable to suppose that it could have a significant impact on the ways in which our brains work.

In particular, Greenfield highlights the impact these changes are having on young people, where she believes that the combined effects of the greater plasticity of the brains of young people and the extensive exposure to television, computers and video games is leading to a shortening of attention spans. Possibly the phenomenal growth in the popularity of Twitter, where each message is limited to just 140 characters, is testament to this change.

Edward Hallowell, a psychiatrist who specialises in attention deficit disorders recently said: "Never before in human history have our brains had to process as much information as today." He went on to say that as a result, people are "losing the tendency to think and feel" and "sacrificing depth and feeling and becoming cut off and disconnected from other people."

However, other observers argue that, far from making us less sociable, the growth in social networking sites such as MySpace and Facebook is actually making us more sociable and the technology is enabling us to increasing our network of contacts. However, just because someone connects to you as a "friend" on Facebook, it does not mean that are an actual friend in the real world.

This "Facebook effect" has been investigated by Robin Dunbar, Professor of Evolutionary Anthropology at Oxford University. In the 1990s Dunbar developed a theory known as "Dunbar's number" which claimed that the size of the neocortex, the part of the brain used for conscious thought and language, limits the size of the social circles we can manage to around 150 friends, no matter how sociable we are.

Dunbar derived this result from studying social groupings in a variety of societies, from Neolithic villages to modern offices. In the case of the Internet, he has found that his theory still holds true. Despite the fact that a person may have more than a thousand "friends" on Facebook, Dunbard has found that when you analyse the traffic on the site, that for each individual the majority of the traffic revolves around an inner circle of up to 150 people.

So it appears that the technology is not enhancing our abilities, but could it be that the constant stimulation created by all this information is improving our IQ - effectively making us smarter?

Colin Blakemore, professor of neuroscience at the universities of Oxford and Warwick said: "One of the things we have learnt over the past 20 years is that the brain does have the capacity to grow and increase in size depending on how it is used. Perhaps the personal experience of having to deal with all this new information will cause new nerve cells to be born and create new nerve connections in the brain."

My own opinion is that to see the deluge of data as either a benefit or a concern is to misunderstand the nature of the way in which we think and process information. We know that the average human being is only capable of consciously processing around 4 pieces of information at any one time (this is why it is easy to miss things if you get distracted) and that in order to cope with this situation, your brain relies on its memory to jump to a conclusion.

Take the famous optical illusion shown here as an example. When you look at the image your eyes scan in the image and your brain gets to work on deciding what it is a picture of. However, contrary to what you might think, your brain does not wait until it has all the information before trying to work it out, as soon as it has the outline it begins comparing what your eyes are seeing with the information stored in your memory. Once it has a match, it makes a decision based more on your memories that on what you are seeing. That is why, once you have seen the image as being either a rabbit or a duck, it is difficult to see it as anything else.

The reason our brain leaps to conclusions in this way is because we simply do not have the time to process all the information. If you have ever tried to draw a picture of a human face you will be aware of how complex it is, yet as humans we are able to recognise the face of a person we know in a fraction of a second. Our brains are therefore used to being bombarded with vast amounts of information and are more than capable of protecting us from overload.

Ironically, this is not the first time in history that people have worried about the human brain being overloaded by too much information; the same concerns were expressed in the Middle Ages following the invention of the printing press!

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Published January 2010

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