LOS ANGELES, CA (Catholic Online) - At the typical social event, there is music is playing, glasses clinking and dozens of conversations drive up the decibel level. However, with all those distractions, the average person can zero in on the one conversation that they want to hear.

This ability to hyper-focus on one stream of sound amid a cacophony of others is what researchers call the "cocktail-party effect." Researchers have pinpointed where that sound-editing process occurs in the brain. This function resides in the auditory cortex just behind the ear, not in areas of higher thought. The auditory cortex boosts some sounds and turns down others so that when the signal reaches the higher brain, "it's as if only one person was speaking alone," principle investigator Edward Chang says.

As published in the journal Nature, the study underscores why people aren't very good at multitasking. Our brains are wired for "selective attention" and can focus on only one thing at a time. This has helped humans survive in a world buzzing with visual and auditory stimulation. But we keep trying to push the limits with multitasking, sometimes with tragic consequences. Drivers talking on cell phones, for example, are four times as likely to get into traffic accidents as those who aren't.

Many accidents can be traced to "inattentional blindness," in which people can turn a blind eye to things they aren't focusing on. Images land on our retinas and are either boosted or played down in the visual cortex before being passed to the brain, just as the auditory cortex filters sounds.

"It's a push-pull relationship -- the more we focus on one thing, the less we can focus on others," Diane M. Beck, an associate professor of psychology at the University of Illinois says.

"We largely see what we expect to see," Daniel Simons, one of the study's creators and now a professor of psychology at the University of Illinois. In his book, "The Invisible Gorilla," co-authored with Christopher Chabris, the more attention a task demands, the less attention we can pay to other things in our field of vision. That's why pilots sometimes fail to notice obstacles on runways and radiologists may overlook anomalies on X-rays, especially in areas they aren't examining.

In order to prevent our brains from ignoring the obvious, researchers have a list of suggestions:

- Recognize your limitations. The brain can only fully attend to one thing at a time.

- Make your senses work together. If you're trying to listen to someone in a noisy room, look directly at the speaker.

- Focus on what's important. Many professions, from pilots to police officers, depend on keen powers of observation. Training and practice help. But experts say things like chess and video games won't likely expand your overall attention skills.

- Allocate blocks of time to specific tasks. Sometimes a deadline can force people to focus.

- Avoid distracted driving. Don't talk on a cell phone, text or give voice commands while at the wheel.

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