Cell Fu

Cognitive psychologists, neurologists and other researchers are beginning to study the impact of constant multitasking, whether behind a desk or the wheel or on foot. It might stand to reason that someone looking at a phone to read a message would misstep, but the researchers are finding that just talking on a phone takes its own considerable toll on cognition and awareness.

Sometimes, pedestrians using their phones do not notice objects or people that are right in front of them — even a clown riding a unicycle. That was the finding of a recent study at Western Washington University in Bellingham, Wash., by a psychology professor, Ira Hyman, and his students.

One of the students dressed as a clown and unicycled around a central square on campus. About half the people walking past by themselves said they had seen the clown, and the number was slightly higher for people walking in pairs. But only 25 percent of people talking on a cellphone said they had, Mr. Hyman said.

He said the term commonly applied to such preoccupation is “inattention blindness,” meaning a person can be looking at an object but fail to register it or process what it is.

Particularly fascinating, Mr. Hyman said, is that people walking in pairs were more than twice as likely to see the clown as were people talking on a cellphone, suggesting that the act of simply having a conversation is not the cause of inattention blindness.

One possible explanation is that a cellphone conversation taxes not just auditory resources in the brain but also visual functions, said Adam Gazzaley, a neuroscientist at the University of California, San Francisco. That combination, he said, prompts the listener to, for example, create visual imagery related to the conversation in a way that overrides or obscures the processing of real images.

By comparison, walking and chewing gum (that age-old measure of pedestrian skill at multitasking) is a snap.

“Walking and chewing are repetitive, well-practiced tasks that become automatic,” Dr. Gazzaley said. “They don’t compete for resources like texting and walking.”

Further, he said, the cellphone gives people a constant opportunity to pursue goals that feel more important than walking down the street.

“An animal would never walk into a pole,” he said, noting survival instincts would trump other priorities.

via www.nytimes.com