HALIFAX, Nova Scotia, July 4 (UPI) -- A Canadian doctoral student says hands-free cell phones are not safer and may even be more dangerous than hand-held cell phones.

Yoko Ishigami, an international student from Shizuoka, Japan, at Dalhousie University, presented her findings at the national conference of the Canadian Association of Road Safety Professionals last month in Whistler, British Columbia.

"Talking and listening are such complicated tasks, especially if you're thinking ahead to what you're going to say," Ishigami said in a statement. "The conversation is what takes all your attention."

Ishigami examined research on cell phone use showing that talking on the phone, regardless of phone type, has negative impact on performance, especially when the driver is confronted by complex or unpredictable situations. Performance while using a hands-free phone was rarely found to be better than that a hand-held phone.

"People tend to be over confident with hands-free and drive faster. They're thinking, 'I'm OK because I've got on the headgear,'" she said. "Whereas if they were driving with a hand-held phone, they tend to drive slower."

One Canadian study demonstrated that talking on a cell phone while driving increased the risk of an accident four-fold, and that whether the phone was hand-held or hands-free made no difference, Ishigami said.