A CAR鈥橲 judgement on the driver鈥檚 levels of alertness could be more reliable than the driver鈥檚 own perception of it.
So say Eike Schmidt of car manufacturer Daimler in B枚blingen, Germany, and his team, after tests on volunteers during a 4-hour drive along the autobahn. To make the drive as boring as possible, the drivers were asked not to chat or listen to the radio.
Every 20 minutes, the team asked the volunteers how attentive they were feeling. They also tested the volunteers鈥� reaction times by asking them to push a button attached to their thumbs every time they heard a certain tone. Each driver鈥檚 heart rate and brainwave frequency, which are indicators of attentiveness, were also recorded during these tasks.
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The team found that while all measures of alertness declined over the 4-hour period, in the final hour the drivers reported feeling more vigilant than the physiological tests suggested ().
It points to the importance of alertness monitoring systems, Schmidt says. 鈥淚f the person鈥檚 saying, 鈥極h, I鈥檓 awake,鈥� and the system鈥檚 saying, 鈥榊ou鈥檙e not,鈥� the system might very well be right.鈥�
