Multitasking

According to Meyer, Evans and Rubinstein, converging evidence suggests that the human "executive control" processes have two distinct, complementary stages. They call one stage "goal shifting" ("I want to do this now instead of that") and the other stage "rule activation" ("I'm turning off the rules for that and turning on the rules for this"). Both of these stages help people to, without awareness, switch between tasks. That's helpful. Problems arise only when switching costs conflict with environmental demands for productivity and safety.Although switch costs may be relatively small, sometimes just a few tenths of a second per switch, they can add up to large amounts when people switch repeatedly back and forth between tasks. Thus, multitasking may seem efficient on the surface but may actually take more time in the end and involve more error. Meyer has said that even brief mental blocks created by shifting between tasks can cost as much as 40 percent of someone's productive time.

The process of switching back immediately to a task you've just performed, as many multitaskers try to do, takes longer than switching after a bit more time has passed, say findings published last fall by researchers from the National Institute of Mental Health. The reason is that the brain has to overcome "inhibitions" it imposed on itself to stop doing the first task in the first place; it takes time, in effect, to take off the brakes. If you wait several seconds longer before switching tasks, the obstacles imposed by that shutting-off process are reduced.Managing two mental tasks at once reduces the brainpower available for either task, according to a study published in the journal NeuroImage. Marcel Just of Carnegie Mellon University asked subjects to listen to sentences while comparing two rotating objects. Even though these activities engage two different parts of the brain, the resources available for processing visual input dropped 29% if the subject was trying to listen at the same time. The brain activation for listening dropped 53% if the person was trying to process visual input at the same time."It doesn't mean you can't do several things at the same time," says Dr. Just, co-director of the university's Center for Cognitive Brain Imaging. "But we're kidding ourselves if we think we can do so without cost."

The mental habit of dividing one's attention into many small slices has significant implications for the way young people learn, reason, socialize, do creative work and understand the world. Although such habits may prepare kids for today's frenzied workplace, many cognitive scientists are positively alarmed by the trend. "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," says Jordan Grafman, chief of the cognitive neuroscience section at the National Institute of Neurological Disorders and Stroke (NINDS). Decades of research (not to mention common sense) indicate that the quality of one's output and depth of thought deteriorate as one attends to ever more tasks. Some are concerned about the disappearance of mental downtime to relax and reflect. Roberts notes Stanford students "can't go the few minutes between their 10 o'clock and 11 o'clock classes without talking on their cell phones. It seems to me that there's almost a discomfort with not being stimulated--a kind of 'I can't stand the silence.'"

ALTHOUGH MANY ASPECTS OF THE networked life remain scientifically uncharted, there's substantial literature on how the brain handles multitasking. And basically, it doesn't. It may seem that a teenage girl is writing an instant message, burning a CD and telling her mother that she's doing homework--all at the same time--but what's really going on is a rapid toggling among tasks rather than simultaneous processing. "You're doing more than one thing, but you're ordering them and deciding which one to do at any one time," explains neuroscientist Grafman.

"The bottom line is that you can't simultaneously be thinking about your tax return and reading an essay, just as you can't talk to yourself about two things at once," he says. "If a teenager is trying to have a conversation on an e-mail chat line while doing algebra, she'll suffer a decrease in efficiency, compared to if she just thought about algebra until she was done. People may think otherwise, but it's a myth.

The big finding of a 2005 survey of Americans ages 8 to 18 by the Kaiser Family Foundation, co-authored by Roberts, is not that kids were spending a larger chunk of time using electronic media--that was holding steady at 6.5 hours a day (could it possibly get any bigger?)--but that they were packing more media exposure into that time: 8.5 hours' worth, thanks to "media multitasking"--listening to iTunes, watching a DVD and IMing friends all at the same time. Increasingly, the media-hungry members of Generation M, as Kaiser dubbed them, don't just sit down to watch a TV show with their friends or family. From a quarter to a third of them, according to the survey, say they simultaneously absorb some other medium "most of the time" while watching TV, listening to music, using the computer or even while reading.

He said our brains are not actually physically capable of handling multiple active tasks at the same time. Active tasks require attention. He said there are two types of multitasking: switch-tasking and background-tasking.

“Background tasking is where something mindless or mundane is happening in the background, that would be like running on the treadmill while you’re watching TV,” Crenshaw said. “That’s not really multitasking.”

He said in contrast, switch-tasking involves more active tasks like driving while talking on the cell phone or surfing the Internet while listening to a lecture. When we do two active tasks simultaneously, Crenshaw said, our brain under-performs because it is actually switching rapidly between tasks. Crenshaw said every switch incurs a switching cost, which equals lost time and effort

Chunking describes how human memory utilization works. It is important to remember this concept as we look at doing several tasks "simultaneously." We are in fact switching between them rather than doing them at the same time.

Multitasking was once heralded as a fantastic way to maximize one’s time and get more done in a day. Then people started realizing that when they had a phone in their ear and were making calculations at the same time, their speed and accuracy (not to mention sanity) suffered. Rather than multitasking, try a new strategy known as “chunking.”

Don't waste so much of your time trying to multi-task. Instead, make yourself more efficient and more productive by chunking. Set aside chunks of time for specific tasks Reduce the time spent in start-up moments Don't allow interruptions Increase the number and size of chunks during your day and week Recognize that there will still be interruptions no matter how well you chunk.

"Heavy multitaskers are lousy at multitasking... The more you do it, the worse you get," said Stanford communications professor Clifford Nass.

Compulsive media multitaskers are worse at focusing their attention, worse at organizing information, and worse at quickly switching between tasks, the Stanford scientists wrote.

After testing about 100 Stanford students, the scientists concluded that chronic media multitaskers have difficulty focusing and are not able to ignore irrelevant information.

Multitasking, when it comes to paying attention, is a myth. The brain naturally focuses on concepts sequentially, one at a time. At first that might sound confusing; at one level the brain does multitask. You can walk and talk at the same time. Your brain controls your heartbeat while you read a book. A pianist can play a piece with left hand and right hand simultaneously. Surely this is multitasking. But I am talking about the brain’s ability to pay attention… To put it bluntly, research shows that we can’t multitask. We are biologically incapable of processing attention-rich inputs simultaneously.

When most people refer to multitasking they mean simultaneously performing two or more things that require mental effort and attention. Examples would include saying we’re spending time with family while were researching stocks online, attempting to listen to a CD and answering email at the same time, or pretending to listen to an employee while we are crunching the numbers.

So there’s no such thing as multitasking. Just task switching – or at best, background tasking, in which one activity consumes our attention while we’re mindlessly performing another.

Even though the study did not revolve around interruptions from cellphones or other gadgets, one researcher said the results provide a “clear extrapolation” to the impact of a stream of incoming rings and buzzes. “Technology provides so much more of an interference than what we did here,” said the researcher, Dr. Adam Gazzaley, a neurologist at the University of California at San Francisco. Indeed, the paper argues that studies like this are becoming increasingly important as aging adults spend more time in a work force with heavy multitasking demands.

the research shows instead is a “diminished ability” to reactivate the networks involved in the initial task.

A growing body of research shows that juggling many tasks, as so many people do in this technological era, can divide attention and hurt learning and performance. Does it also hinder short-term memory?

When we talk about multitasking, we are really talking about attention: the art of paying attention, the ability to shift our attention, and, more broadly, to exercise judgment about what objects are worthy of our attention.

When people do their work only in the “interstices of their mind-wandering,”

their culture may gain in information, but it will surely weaken in wisdom.

Nass is skeptical. In a recent unpublished study, he and his colleagues found that chronic media multitaskers—people who spent several hours a day juggling multiple screen tasks—performed worse than otherwise similar peers on analytic questions drawn from the LSAT. He isn't sure which way the causation runs here: It might be that media multitaskers are hyperdistractible people who always would have done poorly on LSAT questions, even in the pre-Internet era. But he worries that media multitasking might actually be destroying students' capacity for reasoning.

is whether media multitasking is driven by a desire for new information or by an avoidance of existing information. Are people in these settings multitasking because the other media are alluring—that is, they're really dying to play Freecell or read Facebook or shop on eBay—or is it just an aversion to the task at hand?"

But those scholars also became intrigued by the range of individual variation they found. Some people seemed to be consistently better than others at concentrating amid distraction. At the same time, there were no superstars: Beyond a fairly low level of multitasking, everyone's performance breaks down. People can walk and chew gum at the same time, but not walk, chew gum, play Frisbee, and solve calculus problems.

keeping up several e-mail and instant message conversations at once, text messaging while watching television and jumping from one website to another while plowing through homework assignments.

the researchers realized those heavy media multitaskers are paying a big mental price

Everything distracts them

In every test, students who spent less time simultaneously reading e-mail, surfing the web, talking on the phone and watching TV performed best.

college students who routinely juggle many flows of information, bouncing from e-mail to web text to video to chat to phone calls, fared significantly worse than their low-multitasking peers

We call those high multitaskers ... who are constantly using many things at one time when it comes to media. So let's say they're doing e-mail while they're chatting, while they're on Facebook, while they're reading Web sites, while they're doing all these other things. And low multitaskers are people who really are more one-at-a-time people. When they're texting, they're texting. When they're reading a Web site, they're reading a Web site. So those are the low multitaskers.

It turns out multitaskers are terrible at every aspect of multitasking. They're terrible at ignoring irrelevant information; they're terrible at keeping information in their head nicely and neatly organized; and they're terrible at switching from one task to another.

And when people started a third task, one of the original goals disappeared from their brains,

What that suggests, the researchers say, is that multi-task are more easily distracted by irrelevant information. The more we multi-task, the less we are able to focus properly on just one thing.

we've become habituated to checking e-mails and texts, and turn towards the "safe novelty" of Facebook rather than the important but tricky stuff of real life.

Indeed, media multi-tasking sounds, at first glance, like a boon for productivity. If we can do two things at once, we can do twice the amount in the same length of time, or the same amount in half the time

Even if you learn while multi-tasking, that learning is less flexible and more specialized, so you cannot retrieve the information as easily.

"Our results suggest that learning facts and concepts will be worse if you learn them while you're distracted,