Researchers in the US have found your brain waves change when sending text messages on your smartphone.

Sending text messages can change the rhythm of your brain waves, according to a new study.

To find out more about how the brain works while sending a text message on a smartphone, a team of US researchers at the Mayo Clinic in Jacksonville, Florida have analysed data from 129 patients over 16 months.

Their brain waves were monitored electroencephalograms (EEGs) combined with video footage.

Professor of neurology William Tatum says they found a unique "texting rhythm" in approximately one in five patients.

The patients were asked to perform activities such as message texting, talking on the phone and finger tapping in addition to tests of attention and cognitive function.

Only text messaging produced the newly observed brain rhythm, which was different than any previously described brain rhythm.

"We believe this new rhythm is an objective metric of the brain's ability to process non-verbal information during use of electronic devices and that it is heavily connected to a widely distributed network augmented by attention or emotion," Dr Tatum said.

Next to smartphones, the "texting rhythm" was also found in iPad users, according to the study published in the medical journal Epilepsy & Behavior.

It is believed the this new brain rhythm may be due to the devices smaller screens, which require more concentration.

With little known of the neurological effects of smartphone use, this finding could have significant implications for brain-computer interfacing, gaming - and, perhaps most importantly, driving.

"There is now a biological reason why people shouldn't text and drive - texting can change brain waves," Dr Tatum said.

There is still a lot more research needed but Dr Tatum says they have begun to unravel the responses generated by the brain when it interacts with computerised devices.