Cathy Payne, USA TODAY
Hands down - left-brain thinkers use their right hand to hold their cellphone, a new study finds.
The study shows a strong correlation between brain dominance and the ear used to listen to a cellphone, says Michael Seidman, the study's lead author. If your hearing ability is the same in both ears and you hold your phone to your right ear, you are likely to be left-brain dominant. Your speech and language centers are likely to be on the left. If you hold your phone to the left side, you are likely to be right-brain dominant.
Among 717 survey respondents, 90% were right-handed, 9% left-handed and 1% ambidextrous. Among those who were right-handed, 68% said they hold the phone to their right ear. About 25% used the left ear and 7% used both ears.
People reported that they use the right ear because "it sounds better," Seidman says. "If you put a phone to your right ear, 90-plus percent of the messages are going to the left side. The left side of the brain controls the right side of the body. It is a quicker route to the speech and language centers."
Left-brain-dominant people are more likely to use their right hand for daily tasks, such as writing. Right-brain-dominant people are more likely to use their left hand.
But Seidman says the practice of right-handed people listening with their right ear is illogical. It is challenging to hold the phone and take notes at the same time with the right hand, he adds.
Susan Bookheimer, director of the Staglin Imaging Center for Cognitive Neuroscience at UCLA, says in an e-mail that the results show about equal proportions of right-handers holding the phone with their right hand and left-handers using the phone with their left hand. "The logical conclusion should be that individuals are more likely to hold the phone in their dominant hand than in their non-dominant hand," she says.
Seidman says, "Our findings have several implications, especially for mapping the language center of the brain."
"By establishing a correlation between cerebral dominance and sidedness of cellphone use, it may be possible to develop a less invasive, lower-cost option to establish the side of the brain where speech and language occur rather than the Wada test," says Seidman, director of the division of otologic and neurotologic surgery in the Department of Otolaryngology-Head and Neck Surgery at Henry Ford Hospital in Detroit. The Wada test is a procedure that injects an anesthetic into the carotid artery to put part of the brain to sleep in order to map activity, he adds.
Seidman says studies are underway to look at tumor registry banks of patients with head, neck and brain cancer to evaluate cellphone usage. Concerns persist around a potential link between cellphone use and tumors. Seidman advises using hands-free modes for calls until this is fully understood.
The study was published online today in JAMA Otolarynology-Head & Neck Surgery