LONDON: Driving cars may be sending your brain into reverse, warn scientists - including one of Indian origin - who have found that regularly spendingover two hours a day behind the wheel reduces intelligence.Researchers found that brain power fell faster in middle-aged people who drove long distances every day.They suggest that people who want to protect their brains against the ravages of ageing should minimise their time on the road and find activities that are more mentally stimulating, such as socialising."We know that regularly driving for more than two to three hours a day is bad for your heart," said Kishan Bakrania , from the Leicester University in the UK. "This research suggests it is bad for your brain, too, perhaps because your mind is less active in those hours."Researchers studied lifestyles of more than 500,000 Britons aged 37-73 over five years, during which they took intelligence and memory tests."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 time spent driving," Bakrania said.Researchers found that the 93,000 people who drove for more than two to three hours a day typically had lower brainpower, 'The Times' reported.Over the following five years, their brainpower kept declining faster than for people who did little or no driving."Driving causes stress and fatigue, with studies showing the links between them and cognitive decline," Bakrania said.