Driving for more than two hours a day negatively affects IQ levels, scientists have warned.

科学家警告称，每天驾驶时间超过2小时会对智商产生消极影响。

In what might come as unwelcome news for middle-aged¹ commuters, a recent study found that long periods behind the wheel could speed up the effects of age on the brain.

最近的一项研究发现，长期驾车会加速大脑老化，这对中年通勤族而言并非好消息。

The researchers said that the results could be explained by the fact that the mind is less active on long car journeys.

研究人员表示，产生这一结果的原因可能是在长时间驾驶过程中，大脑不如往常活跃。

The mammoth² project saw more than half a million Britons aged 37-73 studied over a period of five years. Out of these some 93,000 of them drove more than two or three hours a day.

这个规模庞大的研究项目在五年间观察了超过50万名37岁至73岁的英国人。他们中有约93000人每天驾驶时间超过两三个小时。

Researchers found that not only did this proportion of subjects typically have lower brainpower to begin with but their IQ score declined more rapidly over the course of the study than those who did little or no driving.

研究人员发现，通常这部分研究对象不仅在一开始智商水平就偏低，而且研究期间他们的智商下降得比很少开车或不开车的研究对象快。

Kishan Bakrania, a medical epidemiologist at the University of Leicester, told The Sunday Times: 'We know that regularly driving for more than two or three hours a day is bad for your heart. This research suggests it is bad for your brain too, perhaps because your mind is less active in those hours.'

莱斯特大学的流行病学家齐山·巴克兰尼亚向《星期日泰晤士报》透露：“我们知道每天驾驶时间经常超过两三个小时对心脏有害。这项研究表明，每天驾驶时间太长对大脑也有害，这可能是因为大脑在驾车期间不如往常活跃。”

Previous studies have found that long periods of inactivity have a detrimental³ affect on brainpower and Dr Bakrania's research shows similar results for those who watched more than two hours of television a day.

以往的研究已经发现，大脑长时间不活跃会对智力造成不良影响。巴克兰尼亚博士的研究表明，每天看电视时间超过两个小时也会造成类似的后果。

But the study also found using computers actually boosted people's cognitive⁴ stills, leading the scientist to propose another potential factor for driving's negative effects.

但该研究也发现，使用电脑的确会提高人们的认知能力，这使得科学家们对长时间驾驶会产生负面影响的可能原因提出另一种解答。

'Driving causes stresses and fatigue⁵, with studies showing the links between them and cognitive decline.'

“驾驶使人感到紧张和疲惫，研究显示这两者与认知水平下降有关。”