A Western Washington University study found 25 per cent of cell-phone users did not notice the clown on the unicycle. (Journal of Applied Cognitive Psychology)

Never mind driving while talking on a cellphone, new U.S. research shows people have a hard time even walking while talking on a mobile.

In a study out of Western Washington University, researchers planted a polka-dot-dressed clown with a big red nose riding a unicycle around a campus square and measured those who noticed the clown and who didn't.

Just 25 per cent of people talking on their cellphones saw the unicycling clown, compared to 50 per cent of people walking alone, in pairs and even those listening to portable music players.

"We asked, 'Did you notice anything unusual today?' And if they didn't volunteer the clown, we asked them directly, 'Did you see the unicycling clown?'" psychology professor and lead researcher Ira Hyman said in an interview on CBC Radio's As It Happens on Tuesday.

"As you can imagine, cellphone users were the most oblivious," he said.

Almost always, cellphone users were shocked when their lack of awareness was pointed out.

"They're like, What!' And they turn and they're surprised they could have missed that," said Hyman, adding this lack of awareness is one of the "real hazards" of using a mobile.

"When you're on a cellphone you may feel like you're aware of the world around you and it seems that you're connected, but you're unaware of the things you've missed and this is a problem because most people may think, 'I do just fine. I'm aware of what's going on around me.'

"But when you actually show them things they've missed, they can be utterly surprised and wonder how it is that I could have missed such things."

Study after study has shown drivers are less reactive and notice fewer events when talking on a cellphone. Newfoundland and Labrador, Quebec and Nova Scotia have banned drivers from talking on hand-held devices. A similar ban comes into effect in Ontario on Oct. 26.

Interesting results

People often make the argument that talking on a cellphone is no less distracting than listening to a radio or talking to a passenger. Not so, said Hyman.

In a second part of his study, researchers simply observed people talking on mobiles as they walked through crowds.

"Compared to people who were just walking by themselves or walking while listening to their iPhone, or even walking in pairs, cellphone users are slower, they change directions more frequently, they weave and they're much less likely to acknowledge any other people around them."

Ultimately, "it's something about the cellphone conversation which is disrupting," he said.

"Walking is a heck of a lot easier than driving a car. It's something people have been doing their whole lives, and if you can't manage to walk effectively and keep track of the world around you, how much harder is it going to be with the task of driving, which is a much more demanding task."

The study is published in an upcoming issue of the journal Applied Cognitive Psychology.