Why multitasking doesn't work

As the brain is forced to respond to several stimuli at the same time which results in the brain switching between tasks and thus losing time as it determines which task to perform.

Joshua David Bell, 43, is an American Grammy Award-winning violinist whose shows all over world run to packed houses.

At 7.51am, on Friday, January 12, 2007, Bell started to play his Stradvarius violin, for which he had paid more than $3million, at the L'Enfant Plaza subway stop at Washington D.C in the United States.

In the next 43 minutes, Bell played six classical pieces. During the time 1,097 people passed by. Bell had his violin cases open to take donations.

This experiment was the brainchild of Gene Weingarten, a staff writer at the Washington Post.  After the experiment occurred Leonard Slatkin, music director of the National Symphony Orchestra, was asked what he thought would happen if a world famous violinist decided to play his violin incognito at rush hour time and with an audience of around 1000 odd people.

"Let's assume that he is not recognised and just taken for granted as a street musician... Still, I don't think that if he's really good, he's going to go unnoticed. He'd get a larger audience in Europe... but, okay, out of 1,000 people, my guess is there might be 35 or 40 who will recognize the quality for what it is. Maybe 75 to 100 will stop and spend some time listening."

Well things turned out much worse for the award winning violinist who earns as high $1000 per minute and whose concert tickets can cost $100 per ticket. As Weingarten wrote in a later article in the Post "In the three-quarters of an hour that Joshua Bell played, seven people stopped what they were doing to hang around and take in the performance, at least for a minute. Twenty-seven gave money, most of them on the run -- for a total of $32 and change. That leaves the 1,070 people who hurried by, oblivious, many only three feet away, few even turning to look."

Bell, used to appreciation, found six moments particularly painful. As Weingarten put it "It's what happens right after each piece ends: nothing. The music stops. The same people who hadn't noticed him playing don't notice that he has finished. No applause, no acknowledgment."

In his article Weingarten wondered "If we can't take the time out of our lives to stay a moment and listen to one of the best musicians on Earth play some of the best music ever written; if the surge of modern life so overpowers us that we are deaf and blind to something like that -- then what else are we missing."

Christopher Charbis and Daniel Simons in their book The Invisible Gorilla - And Other Ways Our Intuition Deceives Us refer to this situation as inattentional deafness. "When people are focussing attention (visual and auditory) on task - getting to work - they are unlikely to notice something unexpected - a brilliant violinist along the way," write the authors.

But in this day and age this is a rare situation where people are focusing on just one thing. The typical tendency is to try and do multiple things at the same time.  One of the most the common multitasking situation is using a mobile phone while driving. As Charbis and Simons point out "the driving impairments caused by talking on a cell phone are comparable to the effects of driving while legally intoxicated."

Now this is something that we all know about. The solution proposed is using a hands-free while driving. Turns out a hands-free is equally bad. "Experiment after experiment has shown no benefit whatsoever for hands-free phones over handheld ones. In fact, legislation banning the use of handheld phones might even have the ironic effect of making people more confident that they can safely use a hands-free phone while driving," write the authors.

Speaking on multitasking, neurologist Jordan Grafman told the Time magazine: "Kids that are instant messaging while doing homework, playing games online and watching TV, I predict, aren't going to do well in the long run."

Research carried out by psychologists at the University of California, Los Angeles, found that multitasking affects how you learn. What you learn while multitasking is less flexible and is difficult to retrieve later on.

Research carried out by psychologist Rene Marois shows that the human brain faces a "response selection bottleneck". This occurs as the brain is forced to respond to several stimuli at the same time which results in the brain switching between tasks and thus losing time as it determines which task to perform.

Charbis and Simons summarise it best when they say "the main conclusion from studies of multitasking is that virtually nobody does it well: As a rule, it is more efficient to do tasks one at a time rather than simultaneously."

But then it is easier said than done. Multitasking is so much a part of our lives that at times we don't even realize it. As I wrote this article, I was on Gmail chat, chatting up with my friends. I was also replying to emails that were popping up all the time. Other than this, I checked my bank balance on my internet banking account.

In between I replied to a couple of smses and also answered three calls. Half way through the piece I remembered I had to book tickets to New Delhi. After I had booked the tickets I realised I had booked the Mumbai to New Delhi ticket twice, instead of booking return tickets. So much for writing on the perils of multitasking.