The multi-tasking myth

Multi-tasking, or the ability to perform more than one task at the same time, has long been associated with the super-efficient, super-productive lifestyle. Yet a growing body of research shows that the effectiveness of multi-tasking is overrated — and that by focusing on fewer tasks, you just might accomplish more.

A study out of France backs up other recent findings on the limitations of multi-tasking, and in fact, indicates that the brain can perform no more than two complicated jobs at one time.

This doesn’t mean you can’t eat your eggs and drink your coffee while reading the newspaper, but it may mean that you won’t be able to perform the more demanding tasks on your to-do list simultaneously — such as doing your taxes and finishing up a presentation while having a unrelated discussion on your cell phone. In order to perform activities well, the brain can’t handle more than two complex, related activities at once, the study says.

The brain divides and conquers

The reason? The human brain has two lobes that divide the responsibility equally when two tasks are being carried out at the same time, researchers say. Or, in other words, when asked to perform two things at once, the brain divides and conquers by assigning one task to each half of the brain. If given a third mentally taxing task, the brain goes into overload.

“Three-tasking [overwhelms] the capacity of human frontal function. Dual-tasking is alright,” Etienne Koechlin, study co-author and professor at the French National Institute for Health and Medical Research, told HealthDay News. “Human higher cognition is dual in essence, which can explain why people like binary choice and have difficulties in multiple choices [people can easily switch back and forth between two options before making a decision, but not across three alternatives].”

For the small study, published online in Science , researchers used functional used functional magnetic resonance imaging (MRI) to study the brains of people while they were performing fairly complicated tasks that involved letter sequencing.

In the first scenario, study participants were asked to alternate between two different tasks. They were then asked to postpone one task while focusing on completing the other one.

The most surprising finding, Koechlin said, was that when volunteers postponed a task, rather than substituting one for another, the two frontal lobes lit up as they focused on the one task.

After a third task was introduced, the error rate increased three-fold, researchers said.


Tips to boost brain performance

Not surprisingly, sleep, diet, exercise and stress management play a key role in maintaining optimal brain health. It’s advice we’ve all heard before, but healthier lifestyle habits can affect not only your physical well-being, but your cognitive health as well. Here are some tips from the experts:

Reduce your sleep debt. A lack of sleep can lead to reduced productivity — as well as an increase in errors. Experts recommend 8 hours of sleep each night to enhance performance. (See Wanted: More Sleep and Napping Boosts Brainpower.)

Eat mindfully. A diet rich in antioxidants (vitamins C, E and beta carotene), essential fatty acids, B vitamins and magnesium supports memory and other cognitive benefits. Also spices such as curcumin — the yellow pigment found in turmeric – and cinnamon are thought to support brain function. (See Spices of Life.) Experts also advise to be cautious of neurotoxins such as methyl mercury in some seafood.

Calisthenics for the brain. Mental exercise can be important for keeping your brain healthy. Stimulate your brain by taking on new challenges such as learning a new language or mastering a new hobby. Engaging in friendly debate or intellectual conversation stimulates blood flow and strengthens the connections between nerve cells in the brain. And studies show that age-related memory loss can be reduced by activities such as solving puzzles or reading challenging books. (See Boot camp for the brain.)

Exercise regularly. Working out boosts circulation and brain-nurturing chemicals that improve your creativity, reaction time and retention. For a double benefit consider activities that engage both your body and your brain simultaneously such as ballroom dancing.

Manage stress. Prolonged stress has been linked to a reduction in executive functions, motor skills, sleep, mood and the immune system. (See Don’t let stress make you sick.)

Stay positive. After 10 years of research, neuroscientist Richard Davidson at the W.M. Keck Laboratory for Functional Brain Imaging and Behavior found that choosing specific thoughts and emotions can permanently change how the brain works. When participants practiced feeling love and compassion, their brains went into action — connecting and building new circuitry at high speed. Emotions play a strong role in mental acuity and that spending just 10 minutes a day focusing on feeling positive and loving can make you smarter (and happier). (See How to become an optimist.)

Sources: Science abstract and news release; HealthDay News; CareerBuilder

Photo © Stephen Morris

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