The New York Times brings us more evidence that multitasking doesn't work well:
"Multitasking is going to slow you down, increasing the chances of mistakes," said David E. Meyer, a cognitive scientist and director of the Brain, Cognition and Action Laboratory at the University of Michigan. "Disruptions and interruptions are a bad deal from the standpoint of our ability to process information."A slideshow accompanies the article, with images of New Yorkers talking and texting while biking, skateboarding, and walking.
The human brain, with its hundred billion neurons and hundreds of trillions of synaptic connections, is a cognitive powerhouse in many ways. "But a core limitation is an inability to concentrate on two things at once," said René Marois, a neuroscientist and director of the Human Information Processing Laboratory at Vanderbilt University.
Mr. Marois and three other Vanderbilt researchers reported in an article last December in the journal Neuron that they used magnetic resonance imaging to pinpoint the bottleneck in the brain and to measure how much efficiency is lost when trying to handle two tasks at once.
Study participants were given two tasks and were asked to respond to sounds and images. The first was to press the correct key on a computer keyboard after hearing one of eight sounds. The other task was to speak the correct vowel after seeing one of eight images.
The researchers said that they did not see a delay if the participants were given the tasks one at a time. But the researchers found that response to the second task was delayed by up to a second when the study participants were given the two tasks at about the same time.
In many daily tasks, of course, a lost second is unimportant. But one implication of the Vanderbilt research, Mr. Marois said, is that talking on a cellphone while driving a car is dangerous. A one-second delay in response time at 60 miles an hour could be fatal, he noted.
"We are under the impression that we have this brain that can do more than it often can," observed Mr. Marois, who said he turns off his cellphone when driving.