Ever feel like you're effectively stuck in reverse gear while at the wheel? New research has shown the monotony of driving isn't only having an adverse effect on your back - but your IQ as well.

Scientists have said spending more than two hours a day in your car will eventually reduce your intelligence. The claim will certainly support those who think taxi drivers and bus drivers behave like automatons when you engage with them on the roads.

Kishan Bakrania, a medical epidemiologist at Leicester University, said: "We know that regularly driving for more than two to three hours a day is bad for your heart.

"This research suggests it is bad for your brain. too, because your mind is less active in those hours."

It comes after researchers reviewed the lifestyles of more than 500,000 people aged between 37-73. The five-year study measured their intelligence and memory through a series of tests.

One of the main takeaways from the study was that nearly a fifth - some 93,000 - who drove for more than two to three hours a day had 'lower brainpower' than when they began.

Bakrania told The Sunday Times: "Cognitive decline is measurable over five years because it can happen fast in middle-aged and older people. This is associated with lifestyle factors such as smoking and bad diet - and now with your time spent driving."

The same findings are believed to roughly apply to those who watch more than three hours of TV daily over the same period.

Rather conversely, playing games on a computer were said to improve muscle memory.

"Cognitive skills were boosted in people who used computers up to two to three hours a day," Bakrania said. "When watching TV, your brain is less active but using a computer is stimulating."

He pointed to other reasons other than inactivity whilst driving as the reason for a fall in intelligence. "Driving causes stress and fatigue, with studies showing the links between them and cognitive decline."

Researchers in China claimed two years ago that a driver can control a car with his or her mind. The car can be controlled by wearing a headgear that picks up the driver's brain signals, which a computer program sorts and analyses to figure out the driver's command to the car.

Scientists at Nankai University said it took them two years to build the country's first mind-controlled car, which can move forward, backwards, stop and lock and unlock without the driver ever using his or her limbs.

"The [brain signal-reading] equipment comprises 16 sensors that capture EEG [electroencephalogram] signals from the driver's brain. They developed a computer program that selects the relevant signals and translates them, enabling control of the car," researcher Zhang Zhao told Reuters.