"Why is it that with our incredibly complex and sophisticated brain, with 100 billion neurons processing information at rates of up to a thousand times a second, we still have such a crippling inability to do two tasks at once?" Marois, associate professor of Psychology, asked. "For example, what is it about our brain that gives us such a hard time at being able to drive and talk on a cell phone simultaneously?"
Researchers have long thought that a central "bottleneck" exists in the brain that prevents us from doing two things at once. Dux and Marois are the first to identify the regions of the brain responsible for this bottleneck, by examining patterns of neural activity over time. Their results were published in the Dec. 21 issue of Neuron.
"In our everyday lives, we seem to complete so many cognitive tasks effortlessly. However, we experience severe limitations when we try to do even two simple tasks at once, such as pressing a button when a visual stimulus appears and saying a word when a sound is presented. This is known as dual-task interference," Dux, a postdoctoral research associate in the Department of Psychology, said. "We were interested in trying to understand these limitations and in finding where in the brain this bottleneck might be taking place."
The research is particularly timely, as additional states consider banning the use of cell phones while driving.
"While we are driving, we are bombarded with visual information. We might also be talking to passengers or talking on the phone," Marois said. "Our new research offers neurological evidence that the brain cannot effectively do two things at once. People think if they are using a headset with their cell phone while d