Scientists at the University of Sussex found conversations can cause the driver to visually imagine what they are talking about.

This uses a part of the brain normally used to watch the road, the University of Sussex study said.

The findings made the case for all phones to be banned from cars, according to the lead researcher.

It is illegal in the UK to ride a motorcycle or drive using hand-held phones or similar devices.

Drivers can get an automatic fixed penalty notice if caught using one. They will get three penalty points on their licence and a fine of £100.

The law currently says drivers can use hands-free phones, sat navs and two-way radios, but if the police think the driver is distracted and not in control of the vehicle, they could get penalised.

(BBC News)